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http://www.webmedcentral.com/images/Header_Logo.giftext/html2010-09-21T05:56:55+01:00http://www.webmedcentral.com/Mr. Vinod SinghIn Vitro Antibacterial Activity of Lactobacillus Casei Against Enteropathogens
http://www.webmedcentral.com/article_view/698
Background: Lactic Acid Bacteria (LAB) produce various substances that exhibit antagonistic activity against other bacteria. These bacteria as well as the compounds secreted by them have increased attention since they have the potential to inhibit food related pathogens.
Methods: Mild growth inhibitors secreted by Lactobacillus casei in supernatant was used against other pathogenic microorganism. Aim of present study was to determine the antibacterial activity of Lactobacillus casei against enteropathogens. Antibacterial activity was performed with Culture supernatant of Lactobacillus casei against the Klebsiella pneumoniae, Escherichia coli, Salmonella enteritidis and Pseudomonas flourescens. L. casei was inoculated in peptone water for 24 hours incubated at 37 ˚C and supernatant was used for the antibacterial activity. 25μl, 50μl, 75μl and 100μl supernatant were added and Optical density was determined with the help of spectrophotometer at 570 nm.
Results and Conclusions: Our result showed a strong in vitro antibacterial activity against various enteropathogenic bacteria which are the potent source of diarrheal sickness. Highest dose of supernatant shows antibacterial activity in all cases (p< 0.05). Further studies for its potential as an antibacterial agent may be confirmed after in vivo studies.text/html2010-10-02T19:35:34+01:00http://www.webmedcentral.com/Dr. Vinod N SinghAntiinflammatory, antimicrobial and immunomodulatory properties of Lactobacillus casei against Enteropathogenic Escherichia coli
http://www.webmedcentral.com/article_view/873
Purpose: Immunomodulatory as well as in vivo antimicrobial properties of Lactobacillus casei were investigated. L. casei was administered orally in Wistar rats.
Methods: Enteropathogenic Escherichia coli were used. Both live and dead culture of L. casei were used. 2x10 8 CFU/ml of each culture was given to respective group daily from day 1st upto 28th days.
Results: Beneficial effects such as increased adhesive property shown by L. casei, increased hemoglobin content and RBC and decreased WBC counts were observed in LL ( live L. casei ) and LD (dead L. casei ) group when compared with EC group (Administerd E. coli). Serum biomarkers like Serum glutamic pyruvic transaminase (SGPT), Serum glutamic oxaloacteic transaminase (SGOT) and total proteins (TP) were also decreased in LL and LD group. Moreover, L. casei in both live and dead form has decreased the production of pro-inflammatory cytokine (IL-6 and α TNF) while it has increased anti-inflammatory cytokine (IL-10). Histopathological analysis also confirmed the protective effect of L. casei against enteropathogenic E. coli.
Conclusion: Present study revealed that L. casei consumption may provide gastrointestinal tract immunity against enteropathogenic E. coli
Key words: Lactobacillus casei, Enteropathogenic Escherichia coli, IL-6, IL-10, TNF α
Running Title: Lactobacillus casei modulate the expression of anti-inflammatory cytokines in gastrointestinal tract.text/html2010-09-10T16:12:07+01:00http://www.webmedcentral.com/Dr. P RanjanAn Approach to Linezolid and Vancomycin against Methicillin Resistant Staphylococcus Aureus
http://www.webmedcentral.com/article_view/590
In vitro activities of linezolid and vancomycin which were evaluated against methicillin resistant Staphylococcus aureus (MRSA). One hundred clinical isolates of MRSA were collected. The minimum inhibitory concentrations (MICs) of linezolid and vancomycin were determined by the Epsilon-test method. The results showed 100 percent susceptibility of linezolid and vancomycin against MRSA isolates. According to the MIC90 values, linezolid was the most active agent. The heterogeneity of methicillin resistance determined by the dropped plate count revealed homogeneous resistance to methicillin of all isolates.text/html2011-05-27T18:43:22+01:00http://www.webmedcentral.com/Dr. Harry HariharanOccurrence and Antimicrobial Drug Resistance of Potential Bacterial Pathogens from Shellfish, Including Queen Conchs (Strombus Gigas) and Whelks (Cittarium pica) in Grenada
http://www.webmedcentral.com/article_view/1943
The trade of mollusks and other shellfish play a significant role in the economy of Grenada. The objective of this study was to gather information on the presence of potential human pathogens in clams, oysters, queen conchs, and whelks (West Indian top shell), and to determine the antimicrobial susceptibility patterns of the bacterial isolates. A total of 110 shellfish consisting of 40 clams, 30 oysters, 20 queen conchs, and 20 whelks, was obtained from three different bays along Grenada’s coast and examined for bacterial pathogens by culture of whole soft tissue, intestines, feces, and/or meat. Selective media, including thiosulfate-citrate-bile-sucrose agar, were used with the aim to isolate various bacteria, particularly the members of the Vibrionaceae family. The isolates obtained were identified based on phenotypic properties, including reactions obtained with the API bacterial identification strips. Of 59 isolates, 35 were identified with >80% probability, with the most prevalent being Vibrio alginolyticus (8), followed by Shewenella putrefaciens (6), and Enterobacter sakazakii (3). Other potential human pathogens included Vibrio fluvialis (2), Stenotrophomonas maltophilia (2), and Vibrio parahaemolyticus (1). All types of shellfish yielded potential human pathogens, including known diarrheal pathogens, Vibrio fluvialis from conch and oysters, and V. parahaemolyticus from clams. On the antimicrobial drug susceptibility tests for the 35 isolates, using a standard disk diffusion method against 10 antimicrobial drugs, none of the isolates demonstrated resistance to the fluoroquinolone drug enrofloxacin. Rate of resistance among other drugs was highest to ampicillin (60%), and lowest to ciprofloxacin and trimethoprim-sulfa (2.9%). In conclusion, this study revealed the presence of potential human pathogens, as well as antimicrobial drug resistance among bacterial isolates from shellfish in Grenada. SHORT RUNNING TITLE: Bacterial pathogens from shellfish in Grenada, and their drug resistanceKEY WORDS: Shellfish, bacterial pathogens, drug resistance, Grenadatext/html2012-05-17T16:28:10+01:00http://www.webmedcentral.com/Dr. Rajdeep DasAn Overview of Changing Trends in Systemic Fungal Infections
http://www.webmedcentral.com/article_view/3386
Background:Invasive mycoses are a significant and growing public health problem. The increasing use of invasive monitoring and aggressive therapeutic technologies in intensive care units has resulted in improved survival of individuals with life-threatening illnesses, but has also contributed to an increase in number of persons at risk for fungal infections. This review discusses the changing patterns in the risk factors, epidemiology; the impact of changes in medical practice on the incidence of systemic fungal infection and the emergence of antifungal resistance.Materials and Methods:Relevant English-language articles were identified through search on four databases [PubMed, ProQuest, Medline and Embase (all, 2000-2011)] conducted in September 2011 using keywords “systemic fungal infection”, “aspergillosis”, “candidosis” and “antifungal”. Original research and review articles related to patients with systemic fungal infection were considered for the review.Result:Despite marked reduction in the rates of invasive fungal infections, in developed countries, the burden is increasing largely in developing countries. Infections with Candida albicans may be decreasing in frequency, the number of persons at risk for them continues to grow. Prolong and deep neutropenia and treatments neutralizing macrophage inflammatory cytokines have increased the likelihood of opportunistic infections. Extensive use of fluconazole in neutropenic patients has resulted in marked decrease in the incidence of invasive candidosis but it has resulted into a shift from highly susceptible to less susceptible Candida sppConclusion:Continued research is required to meet the challenges associated with changes in epidemiology and resistance development.text/html2010-09-17T18:04:24+01:00http://www.webmedcentral.com/Prof. Laila NimriCommunity-Acquired Urinary Tract Infections in a Rural Area in Jordan: Predominant Uropathogens, And their Antimicrobial Resistance
http://www.webmedcentral.com/article_view/660
Introduction:
Urinary tract infections (UTIs) are among the most common bacterial infections and frequently recurring problems encountered by clinicians in community practice. The approach to these infections remains a difficult and sometimes controversial issue, especially in asymptomatic and symptomatic bacteruria. The objectives of this study were to determine the incidence of community acquired UTI in a rural area, the clinical characteristics, risk factors, the uropathogens and their antimicrobial susceptibilities to commonly used antimicrobials.Methods:
Urine cultures and urine analysis were performed on 250 urine specimens collected from patients diagnosed as having a urinary tract infection upon admission. Quantitative bacteriologic cultures, identification of isolates, and antimicrobial susceptibility tests were performed by standard methods.Results:
Escherichia coli was the predominant uropathogen (46.4%) isolated from acute uncomplicated infections (46.4%), followed by Candida spp. (14.9%) Klebsiella spp, Proteus spp., and Pseudomonas spp. Staphylococcus saprophyticus accounted for (7.8%) of the female cases and was associated with uncomplicated UTIs. The lowest incidence of UTIs (10%) was seen among the 13-20 year old age group. Complains of frequent infections of the lower urinary tract accounted for 40.5% of the cases. Resistance of the isolates to used antimicrobials were consistent with those reported in the literature.Conclusions:
The incidence of UTIs is high and was influenced by the patient’s age, sex, and previous antibiotics use. The high frequency of single and multiple antimicrobial resistance of the pathogens to the prescribed antibiotics in this rural community demonstrated decreased usefulness of common antibiotics and emphasizes the need for frequent re-evaluation of the prevalence of uropathogens in such areas and the adjustment of the empirical first-line treatment accordingly.text/html2010-09-20T16:35:07+01:00http://www.webmedcentral.com/Prof. Laila NimriCommunity-Acquired Urinary Tract Infections in a Rural Area: Predominant Uropathogens, and their Antimicrobial Resistance
http://www.webmedcentral.com/article_view/679
Introduction: Urinary tract infections (UTIs) are among the most common bacterial infections and frequently recurring problems encountered by clinicians in community practice. The approach to these infections remains a difficult and sometimes controversial issue, especially in asymptomatic and symptomatic bacteruria. The objectives of this study were to determine the incidence of community acquired UTI in a rural area, the clinical characteristics, risk factors, the uropathogens and their antimicrobial susceptibilities to commonly used antimicrobials.Methods: Urine cultures and urine analysis were performed on 250 urine specimens collected from patients diagnosed as having a urinary tract infection upon admission. Quantitative bacteriologic cultures, identification of isolates, and antimicrobial susceptibility tests were performed by standard methods.Results: Escherichia coli was the predominant uropathogen (46.4%) isolated from acute uncomplicated infections (46.4%), followed by Candida spp. (14.9%) Klebsiella spp, Proteus spp., and Pseudomonas spp. Staphylococcus saprophyticus accounted for (7.8%) of the female cases and was associated with uncomplicated UTIs. The lowest incidence of UTIs (10%) was seen among the 13-20 year old age group. Complains of frequent infections of the lower urinary tract accounted for 40.5% of the cases. Resistance of the isolates to used antimicrobials were consistent with those reported in the literature.Conclusions: The incidence of UTIs is high and was influenced by the patient’s age, sex, and previous antibiotics use. The high frequency of single and multiple antimicrobial resistance of the pathogens to the prescribed antibiotics in this rural community demonstrated decreased usefulness of common antibiotics and emphasizes the need for frequent re-evaluation of the prevalence of uropathogens in such areas and the adjustment of the empirical first-line treatment accordingly.text/html2010-09-24T19:00:58+01:00http://www.webmedcentral.com/Mr. Mariza P De MeloToxicity of indole-3-acetic acid combined with horseradish peroxidase on Staphylococcus aureus
http://www.webmedcentral.com/article_view/695
We investigated the action of indole-3-acetic acid (IAA) combined with horseradish peroxidase (HRP) on Staphylococcus aureus death. S. aureus is a pathogen microorganism capable of causing several diseases. S. aureus was incubated for 1.5, 3.0, and 6.0 h in the absence (control) and presence of IAA, HRP or both IAA/HRP and was then examined: Colony formations, membrane integrity and membrane depolarization. Hydrogen peroxide (H2O2) and superoxide anion (O2.-) production by IAA/HRP and their roles in S. aureus death were also evaluated. The gathered data were tested by ANOVA and Tukey test, using P-.text/html2010-10-20T15:19:29+01:00http://www.webmedcentral.com/Mr. Shanmugavel LingathuraiBacteriological Quality And Safety Of Raw Cow Milk In Madurai, South India
http://www.webmedcentral.com/article_view/1029
The microbiological quality and safety of raw milk from 60 dairy farms in Madurai were determined. Milk samples were collected at 60 centers from four regions, namely northern, eastern, western and southern (NEWS) according to stratified random sampling design. Samples were analyzed for Total plate count (TPC), psychrotrophs, thermophiles, Staphylococcus aureus, coliform, Escherichia coli 0157: H7 and Salmonella. The mean counts per ml for TPC, psychrotrophs and thermophiles were 12.5x106, 5x103 and 6.85x103 respectively. From the 60 milk samples tested, coliform bacteria contaminated approximately 90% and 70% were E. coli positive, with mean counts ranged from 103to 104 cfu ml-1. S. aureus was isolated from more than 61.7% of the samples and the mean count per ml was 6.2x103. Meanwhile, E. coli 0157: H7 was also detected in 39 (65%) samples. However, Salmonella was only detected in 8 (13.3%) of the samples with the southern region having the highest frequency of isolation.text/html2010-12-10T19:38:14+01:00http://www.webmedcentral.com/Ms. Vaishnavi M AnsingkarIncidences Of Endophytic Human Pathogens In Fresh Produce
http://www.webmedcentral.com/article_view/1299
The frequency of documented outbreaks of human illness associated with consumption of consumption of raw fruits and vegetables has increased in recent years. In present study 10 different fresh produce were proceed for standard plate count to evaluate the existence of endophytic bacterial human pathogens. This study revealed that out of the tested samples 60% were found to be contaminated with Salmonella spp. While 50% were loaded with endophytic Escherichia coli O157:H7. Maximum contamination was observed in leafy vegetables like spinach and coriander. While in Carrot, onion and radish pathogens was not observed. The potential internalization of pathogens in fresh produce is a concern of food safety and enlight the chances of epidemic outbreaks.
Key Words: Endophyte, Salmonella spp., Escherichia coli O157:H7, Fresh produce.text/html2011-01-10T13:17:50+01:00http://www.webmedcentral.com/Dr. Shobha KLPrevalence Of Non-fermenters In Urinary Tract Infections In A Tertiary Care Hospital
http://www.webmedcentral.com/article_view/1464
Background and Objective: Aerobic nonfermenting gram-negative bacilli (non-fermenters) are now emerg­ing as important uropathogens. This study was done to know the prevalence of non-fermenters in Urinary Tract Infections (UTI) along with their antibiotic sensitivity.
Method: 5436 mid stream urine specimens received in six months period from July to December 2007 were subjected to Gram,s staining ,semi-quantitative culture, biochemical tests and antibiotic sensitivity testing as per the standard procedures in the routine microbiology laboratory and the results were noted.
Results: Out of the 1271 culture positive cases with significant bactereuria, 120 (9.44%) were caused by non-fermenters. Among the non-fermenters, Pseudomonas spp. was the most common (80.84%) followed by Acinetobacter spp. (19.16%). Majority of patients belonged to the age group of 15 to 50 years and most of them were females. Antibiotic sensitivity testing revealed that, among Pseudomonas spp., 75.25% isolates were sensitive to Piperacillin, 71.13% sensitive to Amikacin, 43.30% sensitive to Ciprofloxacin, 31.95% sensitive to Ceftazidime and 91.66% sensitive to Imipenem. In the case of Acinetobacter spp., 73.91% isolates were sensitive to Amikacin, 34.78% sensitive to Norfloxacin and all were sensitive to imipenem. Out of the 18 non-fermenter isolates which were resistant to commonly used antibiotics, 15 were from inpatients indicating the possibility of nosocomial infection.
Conclusion: The non-fermenters are emerging as important cause of Urinary Tract Infections. In this study, Pseudomonas spp. was the most common non-fermenter isolated in significant numbers in MSU specimens. But, Acinetobacter spp. appeared to be more resistant to invitro antibiotics in general.text/html2011-01-25T20:46:17+01:00http://www.webmedcentral.com/Prof. Laila NimriGenetic Homogeneity Of Clinical Isolates Of Brucella Melitensis: A Single Ribotype
http://www.webmedcentral.com/article_view/1508
Introduction: One of the genetic targets frequently used for strain identification and strain phylogeny is the rRNA operon, particularly the 16S rRNA gene. Ribosomal genes in Brucella have been implicated in recombination events that promoted the division of a chromosome into two chromosomes. These genes are highly conserved and diverge very slowly.
Methods: Brucella was cultured or isolated from 100 blood samples that were collected from clinical cases from a rural endemic area in Jordan. The primers used were genus-specific designed to amplify a 905 bp fragment of the highly conserved region within the 16S rRNA of the genus Brucella. The PCR products were subjected to restriction fragment length polymorphism analysis by digestion with HaeIII and MspI separately.
Results: All isolates had the same rRNA gene restriction pattern and identical ribotype. Ribotyping confirms the high levels of DNA-DNA relatedness among Brucella species supporting the conclusion that Brucella is actually a monospecific genus.
Conclusions: Results demonstrated the limited genetic diversity of Brucella isolates and that the rRNA gene might not be a good locus to differentiate between Brucella strains.text/html2011-07-19T19:30:30+01:00http://www.webmedcentral.com/Dr. Hing ChanRecycling of Nutrients from Trash Fish Wastewater for Microalgae Production as Health and Pharmaceutical Products and Renewable Energy
http://www.webmedcentral.com/article_view/2027
Trash fish feeding of cage fish can result in marine pollution. Whole and chopped trash fish can leach pollutants such as ammonia, phosphate and protein into surrounding waters. Reduction of pollution can be achieved by recycling the wastewater generated from trash fish feeding for cultivation of microalgae. Apart from larviculture, microalgae are potent candidates for the production of health and pharmaceutical products. Two microalage, Chlorella saccharophila and Nannochloropsis sp. have the potential to produce high amounts of polyunsaturated fatty acids called ω-3. 31.8 mg of EPA (Eicosapentaenoic acid, C20:5n-3) can be obtained from 1 g dry weight of Nannochloropsis sp. Furthermore, high oil content ranging from 10.7 to 13.6% for Chlorella saccharophila and 9.3% for Nannochloropsis sp. TFA (Total fatty acids/cell dry weight) can be extracted from them respectively. An alternative biofuel derived from microalgae is feasible due to the fact that there is no competition for terrestrial occupation.text/html2011-08-12T18:20:33+01:00http://www.webmedcentral.com/Dr. B N NagpalMicrobiological Quality of Drinking water in the Villages, Rehabilitation and Resettlement Colonies Located in the Area of Major Dams of Narmada Basin, India
http://www.webmedcentral.com/article_view/2084
Microbiological health risks are of major concern during construction of Dam reservoir. Therefore, drinking water was examined for the presence/absence of Salmonella, Citrobactor, Escherichia and Vibrio species in the Indira Sagar/ Omkareshwar Project (ISP/OSP) affected areas and Rehabilitation/Resettlement (RR) colonies of Sardar Sarover Project (SSP) in Madhya Pradesh. V. cholerae and V. parahaemolytica were positive in 24 and 6 water samples respectively. Salmonella and Citrobactor species were found in 21water samples. Drinking water samples of most of the villages located at bank of Narmada River were positive with Vibrio species. While Salmonella and Citrobactor species were present in the drinking water of the nearby villages, Rehabilitation/Resettlement colonies and command areas of the river/ canal. Seasonal variation was also observed in the presence/absence of tested microbes in different survey. Thus, there may be the role of reservoir water in the groundwater microflora change in the nearby areas.text/html2011-10-05T12:46:57+01:00http://www.webmedcentral.com/Dr. Daniel N TagoeBacterial Contamination of Mobile Phones: When Your Mobile Phone Could Transmit More Than Just a Call
http://www.webmedcentral.com/article_view/2294
Background: Mobile phones have become one of the most indispensable accessories of professional and social life. However, several researches have indicated the potential colonization of surfaces and their ability to transmit diseases (fomites) of which the mobile phone is no exception. Thus this present study investigates bacterial contamination of mobile phones and their antibiotic susceptibility patterns.Methodology: Surfaces of 100 mobile phones of randomly selected university students were aseptically swabbed. Serial dilution was used in quantification of bacterial with blood and MacConkey agars used in bacterial isolation. Gram reaction and biochemical reactions were applied in identification and the Kirby Buaer method employed in Antibiotic Sensitivity Testing.Results: There was 100% contamination of all the mobile phones surfaces with a mean bacterial count of 9.915x107cfu/ml with a total of 11 bacteria spp. isolated. The higher isolates include Bacillus cereus (23%) and Proteus mirabilis (19%), whilst the least isolate were Salmonella spp. (3%) and Shigella. spp. (2%). Pathogenic isolates made up 81.8% of all isolates 18.2%. Salmonella spp. and Shigella spp. showed the most resistance to the antibiotics (87.5%) each whilst Escherichia coli was the most susceptible bacteria to the antibiotics (75%). Amikacin (71.4%) and Gentamicin (63.6%) were the most effective antibiotics whilst Ampicillin, Penicillin, Cloxacillin showed the least effectiveness with 100% bacteria resistance.Conclusion: Thus mobile phones can be heavily colonized by high quantities of pathogenic bacteria and thus potential sources of disease transmission requiring application of sound personal hygiene as preventive methods.text/html2011-11-30T09:41:09+01:00http://www.webmedcentral.com/Prof. Laila NimriClinical Relevance of vacA, cagA, and iceA Genotypes of Helicobacter pylori
http://www.webmedcentral.com/article_view/2515
Introduction: Helicobacter pylori infection is associated withvariable clinical outcomes, including gastroduodenal diseases, and genetic factors may be relevant in this process. The aim of this study was to investigate any association between the H. pylori genotypes and the clinical out come in patients diagnosed with gastrointestinal diseases.Methods: Antral gastric biopsy specimens were collected from 250 patients with gastritis. Clinical diagnosis was based on histology, and endoscopy. Specimens were tested for H. pylori genotypes by PCR, and the presence of vacA s and m regions, cagA, and iceA genotypes were analyzed for association with the clinical disease.Results: Significant associations were found betweenthe genotypes vacA s1 with gastritis (P=0.052), and atrophy (P= 0.001), vacA s2 and vacA m2 with erosion (P= 0.004, and < 0.001 respectively), cagA with duodenitis (P= 0.005). Several genotypes present in certain diseases were significantly associated with the patients’ gender, while, no association between the genotypes, and the age of the patient was found.Conclusions: This study reports the genotypes of three virulence genes in H. pylori for the first time in Jordan; it adds new pieces of information in this respect. Overall, the results demonstrated that certain H. pylori genotypes showed significant correlation with the clinical outcome, and their presence might be used to predict the disease outcome.text/html2011-12-18T07:15:00+01:00http://www.webmedcentral.com/Ms. Wendy OngChoices of Antibiotics for MRSA Infection in Malaysia
http://www.webmedcentral.com/article_view/2675
Methicillin-resistant Staphylococcus aureus (MRSA) are found to be common in many countries. A study was done in Hospital Universiti Sains Malaysia (HUSM) showed that there is a gradual reduction in MRSA infection rates from 2002 to 2006. Vancomycin, Linezolid, Daptomycin, Tigecycline, Rifampicin and Teicoplanin are the most common and popular antibiotics for treating MRSA infection in Malaysia. A study show that the patients that treated with Daptomycin achieve clinical success on day 3 (93%) compared to that having Vancomycin treatment (57%). Daptomycin showed 100% efficacy towards killing MRSA strains. In addition, only 10% of patients will complain about the adeverse effects of vancomycin. The most common side effects associated with usage of Teicoplanin are hypersensitivity (2.6%), abnormal liver function (1.7%), fever (0.8%), abnormal renal function (0.7%) and ototoxicity (0.3%). Monitoring and dose adjustment should be carried out to reduce the side effects of the antibiotics used.text/html2012-01-02T09:28:52+01:00http://www.webmedcentral.com/Mr. Olumide A OdeyemiBiofilm Producing Vibrio Species Isolated from Siloso Beach, Singapore : A Preliminary Study
http://www.webmedcentral.com/article_view/2631
This research aim to preliminarily investigate biofilm production among Vibrio species isolated from Siloso beach, Singapore. 100 µL of sea water sample collected was plated on Congo Red Agar (CRA) using spread plate method. The plates were incubated at 30°C for 24 hours. Forty – six biofilm producing black colonies with dry crystalline consistence were further transferred aseptically into freshly prepared Thiosulfate-Citrate-Bile salts-Sucrose agar (TCBS), a selective medium for isolation of Vibrio spp. All the isolates were found to grow on TCBS after 24 hours incubation at 30°C. Biofilm production in marine bacteria is of significance important to public health. The result of this preliminary study speaks volume of the health related danger in recreation water bodies.text/html2012-07-18T19:45:16+01:00http://www.webmedcentral.com/Dr. Birgit PruessThe Role of Activated Acetate Intermediates in the Control of Escherichia Coli Biofilm Amounts
http://www.webmedcentral.com/article_view/3577
A previous study postulated that acetate metabolism was a metabolic sensory mechanism that related information about E. coli’s environment to the formation of biofilms (Prüet al., Arch. Microbiol. 2010). Considering that mutants in pta ackA (no acetyl phosphate) and ackA (high acetyl phosphate) exhibited similarly increased biofilm amounts and three dimensional structures, the hypothesis for this study was that acetyl Co-A was a more likely mediator of the acetate effect than acetyl phosphate. The effect of acetate metabolism on biofilm amounts was detailed by using single carbon sources rather than the previously used mixed amino acid medium, as well as mutations in additional genes that contribute to acetate metabolism (ldhA, pflA, pflB). In summary, the mutations in ackA, pta ackA, and ldhA increased biofilm amounts in the presence of maltose, D-trehalose, D-mannose, and L-rhamnose, all of which get converted to acetyl-CoA. The ackA mutant also exhibited increased biofilm amounts in the presence of inosine and thymidine. The mutation in pflA decreased biofilm amounts in the presence of maltotriose, uridine, D-serine, and acetate. Since ackA, pta ackA, and ldhA mutants are expected to exhibit increased intracellular acetyl-CoA levels, and pflA and pflB mutants likely exhibit decreased acetyl-CoA concentrations, we believe that acetyl-CoA is the activated acetate intermediate that controls biofilm amounts.text/html2012-11-17T22:22:41+01:00http://www.webmedcentral.com/Dr. Hala AwadallaAvian Flu: A possible pandemic threat
http://www.webmedcentral.com/article_view/3830
Background: Influenza viruses infect a wide range of animal hosts and cause yearly wintertime epidemics among people living in temperate zones. Because of their ability to mutate, re-assort gene segments, and cross species, influenza viruses can also lead to pandemics in which immunologically naive people are exposed to a new, highly contagious subtype. In the last century, these pandemics were caused by influenza viruses whose surface attachment proteins, or hemagglutinins, were derived from birds, the natural reservoir of influenza virus. Vaccines are the primary means to provide protection for people at risk for inter-pandemic influenza, and new vaccines, directed against avian-potentially pandemic-strains are now being tested.
Aim: The aim of this study is to examine available information on influenza pandemic in order to create awareness of preventive measures against influenza pandemic and to suggest future research areas in developing control strategies.
Method: Data sources: Review of literature via Internet, articles and journals. Data extraction: Abstracts and articles identified were accessed, read to establish relevance to this review. Data synthesis: Important points were prioritized and then included as subtitles; below each subtitle, published works were included. text/html2013-02-02T07:10:44+01:00http://www.webmedcentral.com/Ms. Vaishnavi M AnsingkarStudies on Survival of Salmonella Typhimurium in Phytopathogen Damaged and Healthy Fresh Produce
http://www.webmedcentral.com/article_view/3988
The ecology of vegetable surface is important to the survival of enteric pathogens. Understanding changes in ecological parameters during the preharvest stages of production can lead to the development of approaches to minimize the hazard of contamination of vegetables with foodborne pathogens. In the present study, survival of Salmonella typhimurium at the time of harvest were compared among the phytopathogen damaged and healthy vegetables. The population density of Salmonella typhimurium decreased over time in the fresh produce regardless the treatment. The salmonella typhimurium count was found to be higher in phytopathogen damaged produce than the healthy produce. The present investigation revealed that, maintaining healthy plants and minimizing biological damage around the time of harvest might improve the safety of fresh produce.
Key words: Salmonella typhimurium, Xanthomonas campestris, spinach, tomato, cucumber, cabbage, Cauliflower.text/html2013-05-09T05:44:56+01:00http://www.webmedcentral.com/Dr. Narotam Sharma Human Papillomavirus Genotyping by Dual Priming Oligonucleotide Technology And Its Clinical Efficacy in Cervical Cancer Management
http://www.webmedcentral.com/article_view/4214
Infection with oncogenic human papillomavirus (HPV) is a necessary source for the progression of cervical cancer. Several types of human papillomaviruses (HPVs) are associated with a range of benign and malignant lesions including genital condyloma and anogenital cancer as well as for the development of genital warts. Six patients came positive for Human papillomavirus. Patients with low grade squamous intraepithelial lesion (LGSIL) and high grade squamous intraepithelial lesion (HGSILS) were highest in number (05). LGSIL positive cases harbored HPV type 16 (03 cases) where as patients with HGSIL were HPV type 16, HPV type 18, HPV mixed types and HPV type 11 positive. A case with cervitis harbored HPV type 16. Discussion: Thus the conventional PCR using DPO technology is helpful for detecting and screening clinically significant HPV genotypes so that the existing vaccines for the particular genotype can be prescribed as well as for HPV types causing generalized and genital warts, proper treatment can be given to the patient. However more epidemiological research on the prevalence of various HPV types is required before the need for regionally-tailored vaccines is confirmed.text/html2013-05-27T12:18:34+01:00http://www.webmedcentral.com/Dr. Julie O OsayandeFerripyoverdine Receptors: A Probable Entrance Route for the good, the bad and the ugly
http://www.webmedcentral.com/article_view/4261
Pseudomonas aeruginosa produces pyoverdine in order to chelate iron, the ferri-pyoverdine complexes formed are internalized by ferripyoverdine transporters (fpvA) present on its outer membrane, three fpvA’s are known (fpvAI, fpvAII, and fpvAIII), the fpvAI was cloned in 1993 by Poole et al. and the other two fpvA’s were cloned by De Chial et al. 2003. Following the speculation that some pyoverdine negative Pseudomonas aeruginosa isolates present in the lungs of cystic fibrosis patients ( De Vos et al. 2001) and that an fpva mutant were growth stimulated by iron, an alternative receptor, termed fpvB was identified by Ghysels et al. 2004. A fragment of this gene was determined by Polymerase Chain Reaction, (PCR). For the first time, using PCR procedures, the complete fpvA and fpvB gene sequences were determined and the sequences from this determination have been deposited in the GenBank database (Bodilis et al. 2009) and some variants of these receptor genes are presented.text/html2013-06-25T04:05:28+01:00http://www.webmedcentral.com/Dr. Julie O OsayandeCystic Fibrosis, an Alternative Ferripyoverdine Receptor, Probable Remedy?
http://www.webmedcentral.com/article_view/4295
Cystic Fibrosis, a common autosomal, recessive hereditary disease which affects many different parts of the body including the lungs, gastrointestinal tract, pancreas, reproductive organs and sinuses is caused by mutation in a gene called the Cystic Fibrosis Trans-membrane Conductance Regulator (CFTR), a gene known to help create sweat, digestive juices and mucus ( Boyle and Boeck, 2013) . Two copies of this gene are found in the system of healthy individuals and only one gene is sufficient enough to prevent cystic fibrosis. It has been documented that approximately 3.3% of white Americans, or nearly 10 million persons, are carriers of a CFTR mutation; the carrier state is also found in 2.2% of Hispanic persons, 1.5% of African American persons and 1.1% of Asian American persons, with a homozygous prevalence in the United States of approximately 1 per 3500 white persons ( Hernanz-Schulman, 2012, Cystic Fibrosis Foundation Report, Plant et al. 2013).Two prevalent theories surrounding this gene mutation disorder have been explained some decade ago and they are termed the “high salt hypothesis” and the “low volume hypothesis “. CFTR gene encodes a protein anchored to the outer membrane of cells in the sweat glands, lungs, pancreas and other surrounding organs; this protein crosses the membrane and acts as a channel connecting the inner part of the cell (cytoplasm) to the surrounding fluid. This channel is primarily responsible for controlling the movement of negatively charged chloride ions outside the cell into the cell and as such a dysfunctional CFTR would mean an accumulation of these negatively charged ions outside the cells, where also are present positively charged ions like sodium, an electric attraction occurs between sodium and chloride ions and a combination of this results in the formation of salt which is lost in high magnitude in the sweat of individuals suffering from cystic fibrosis disease as compared to healthy individuals, this explains the “high salt hypothesis”. On the other hand, the low volume hypothesis supports identical high salt concentration in healthy individuals and cystic fibrosis patients; this hypothesis also states that lack of the CFTR gene enhances sodium absorption accompanied by chloride from the airway surface liquid which passes either through a second pathway (non-CFTR) or paracellularly. The airway surface cells form a monolayer that is leaky to water and as such increased absorption of salt and water in cystic fibrosis collapses the cilia and hence a ceasation in normal ciliary function which include movement of mucus, and it is this ceasation that forms the basis of lung colonization by bacteria since the normal vehicle that moves bacteria out of the lungs cease to function. However, a common feature of these propositions is that majority of the damages observed in cystic fibrosis is due to blockage of the narrow passages of affected organs with dehydrated and thickened secretions (Smith et al. 1996, Masui et al. 1998, Hassett et al., 2002). Bacteria therefore find a home in these secretions or mucus which collects in the small airways, this mucus protects bacteria from the direct attack of the host immune system and in addition, within this mucus, bacteria biofilm also develop allowing them to create a kind of niche for themselves. Majority of the bacteria found to colonize and infect the lungs of cystic fibrosis patients at different stages are Staphylococcus aureus, Hemophilus influenzae (at initial stages) and over time by Pseudomonas aeruginosa and Burkholderia cepacia (O´ Malley, 2009) these bacteria tend to develop special characteristics that enable them adapt and thrive in the environment within the lungs. Pseudomonas, for example have been observed to develop characteristic features permitting the formation of large mucoid colonies composed of alginate (involving the algD genes), which is the mucoid exopolysaccharide consisting of a repeating polymer of mannuronic and glucuronic acid and it is this alginate slime that forms the matrix of the Pseudomonas biofilm which anchors the bacteria cells to their environment and protects them from the host immune response and administered antibiotics. Other features of Pseudomonas aeruginosa isolates from the lungs of cystic fibrosis patients include the possession of several virulence factors like exoenzyme S which has an ADP-ribosylating activity, and encoded by the exoS gene, has been suggested to probably impair the function of phagocytic cells in the blood stream and internal organs thereby making preparation for invasion by Pseudomonas aeruginosa possible , the exotoxin A encoded by the toxA gene is proposed to inhibit protein biosynthesis and in addition possesses necrotizing activity at bacteria colonization site and it is therefore thought to contribute to the colonization process , two other extracellular proteases which also contribute to virulence are the lasB elastase and alkaline protease. lasB elastase, a zinc metalloprotease encoded by the lasB has an elastolytic activity on the lung tissue where it lyses fibronectin to expose receptors for bacterial attachment on the mucosa of the lung, elastase is also known to disrupt the respiratory epithelium and interferes with ciliary function, the alkaline protease on its own interfere with fibrin formation and also possesses a lytic activity. In addition to the mentioned virulence factors, P. aeruginosa also has other soluble proteins involved in invasion, these include cytotoxin, a pore forming protein having cytotoxic effect on eukaryotic cells, a phospholipase and a lecithinase both of which possesses haemolytic activity and act synergistically to break down lipids and lecithin. An extracellular neuraminidase also found in P. aeruginosa has been proposed to play an important role in implantation of the bacterium. Several cystic fibrosis isolates tested are in possession of these genes (Lanotte et al., 2004) whose products are responsible for the numerous toxins and virulence factors produced by this notorious gram negative opportunistic pathogen, majority of which are involved in the evasion of the host immune system.An interesting and important characteristic of this species of gram negative bacteria is their ability to thrive in various ecological niches, which “may” be attributable to their ability to chelate iron which is an essential element for microbial growth and also utilise heterologous iron bearers when in association with other micro-organisms in conditions of iron limitation.Pseudomonas aeruginosa has a special means of obtaining this essential element. Humans for instance have extracellular and intracellular proteins specialised in trapping iron within its system, examples of which are lactoferrin and transferrin , these proteins help to reduce the availability of free iron thereby limiting microbial access to it, however, in situations of iron limitation such as observed within the human system, pathogenic bacteria like Pseudomonas aeruginosa, a known pathogen of cystic fibrosis patients in which it can cause chronic colonisation of the lungs, secrete low molecular weight compounds called siderophores, these compounds are highly efficient iron strippers, able to compete for and bind any available iron (Neilands,1995) which is subsequently utilised for growth and propagation of virulence within a mammalian host , this kind of behavioural exhibitions are also observed in the external environment.The two major siderophores secreted by Pseudomonas aeruginosa are Pyoverdine and Pyochelin, pyoverdine, in addition to being a strong chelator of iron is also known to be essential for virulence of P. aeruginosa (Meyer et al., 1996) based on the failure of pyoverdine deficient mutants to demonstrate virulence in burned mice, showing that this compound is of great importance to these species of bacteria.Large sized complexes are formed between these siderophores and iron and there is need for the internalisation of these complexes so that the bacteria can make use of chelated iron, however, the structure of the cell wall of the gram negative bacteria plays a special role in this internalization process. Diffusion across the gram negative cell membrane is mediated by porins allowing free transport of small size molecules and ions, since the size of these complexes are of several orders of magnitude and concentration of these complexes in the external media is low, bacteria utilizes high affinity receptor proteins located on its outer membrane to initiate the transport process, these receptor proteins are proposed to be used by bacteria to concentrate these complexes at the cell surface and eventually facilitate their uptake into the internal milieu. Several of these receptors have been cloned and identified (Poole et al., 1993) and a number of such is present in the P. aeruginosa genome. In P. aeruginosa, three siderophore receptors namely fpvA I, II and III exists, each binding its cognate ferri-siderophore ligand (Poole et al., 1993; de Chial et al., 2003).In addition to the three cloned siderophore receptors (fpvA I, II and III), an alternative receptor called fpvB was identified (Ghysels et al., 2004) and identification of this receptor was made possible following the creation of a deletion mutant of an fpvA wildtype Pseudomonas aeruginosa strain and it was observed to be responsible for residual ferri-pyoverdine transport and at the time a 562bp of the product of this gene was amplified. Further work by using experimental PCR procedures (Osayande JO, 2009) has led to the amplification and sequencing of about 2.5kb size fpvB gene in several environmental and clinical isolates of Pseudomonas aeruginosa and the sequence of this gene in the various isolates tested was highly conserved (even though one of the strain, strain Mi162 see figure 2 showed a little variation, however the same primer sets were used to amplify and sequence the 562bp fpvB gene in this strain) and results show that about 93% of the P. aeruginosa tested are in possession of this gene, this goes to show that this gene maybe yet another important “not-to-do-without” component of the genome of these species of bacteria and if this is true, may open a new avenue for drug discovery for treatment of bacteria (especially Pseudomonas aeruginosa) infections in cystic fibrosis, which on till now, is still striving for complete cure.Various drug discovery methods in the recent past has involved designing drugs on the basis of iron transport-mediated drug delivery agents (Roosenberg et al., 2000) such as shown below (Figure 1) and detailed biological studies demonstrate a positive indication that this concept of microbial iron transport siderophore- mediated drug delivery, exploiting the active ferric siderophore transport systems is very effective, this concept involves attachment of synthetically made siderophores to drug conjugates (antibiotics) and when microbes recognize these siderophore components as iron delivery agent assimilate the conjugate and in effect are terminated, however, many pathogens recognise and utilize only certain siderophores and such conjugates are thought to have selective antimicrobial activity and apart from this problem of selectivity in antimicrobial activity, third generation antibiotics like the aminoglycosides (penicillins and fluoroquinolones) known to be bactericidal for P. aeruginosa have been extensively studied to require an active transport internalization mechanism in order to exert their bactericidal effect (Hassett et al., 2002; Roosenberg et al., 2000).Therefore, to further narrow the incidence of selective antimicrobial activity and antibiotic uptake or internalization problems, I am of the opinion that an alternate mode of drug delivery system which encompasses a ¨synthetic receptor¨ ( in this case fpvB found in and recognised by about 93% of Pseudomonas aeruginosa strains) linked to a synthetic siderophore- Iron- drug conjugate would go a long way in minimising both incidences. Majority of the drugs known to be effective against isolated biochemical targets become therapeutically ineffective because of their inability to permeate a deleterious cell, this ¨synthetic receptor¨ (fpvB) may speed up the uptake of this drug combination because it “may” quickly be recognised along with siderophore and attached iron.This opinion is based on the one hand, the fact that the fpvB gene has been shown to confer some ability to take up and utilize existing pyoverdine types (in effect, the types 1 and III pyoverdine ) on some clinical and environmental P. aeruginosa isolates (Ghysels et al. 2004), irrespective of the pyoverdine group (three siderovars are known, these include pvdI, pvdII and pvdIII) to which they belong . On the other hand, since bacteria use considerable metabolic energy to synthesise these receptors and their own siderophores (Buchanan, 2005), they will gladly make use of iron linked to an already made siderophore, which in addition is linked to an already made receptor (¨synthetic receptor¨ fpvB) further linked to an antibiotic and in trying to conserve energy, they utilize these drug conjugates and are ultimately terminated.text/html2013-06-27T12:08:41+01:00http://www.webmedcentral.com/Dr. Julie O OsayandeFerripyoverdine receptors and General Metabolism in Pseudomonas aeruginosa, Preliminary Results
http://www.webmedcentral.com/article_view/4302
Pseudomonas aeruginosa is a human opportunistic pathogen ubiquitously distributed in nature. Under iron limiting conditions, this organism secretes pyoverdine which helps to chelate iron to form ferripyoverdine complexes recognized at the outer membrane by ferripyoverdine receptors, these receptors help to transport iron bound to pyoverdine into the internal milieu. This work used P. aeruginosa wildtype and ferripyoverdine receptor mutants (for the first time) cultures as inoculums for the VITEK 2 (bioMerieux) biochemical identification system to study the possible role ferripyoverdine receptors might play in the ability of P. aeruginosa to utilize substrates impregnated in the VITEK 2 GNI cards, in the presence of iron and gentamicin, differential utilization of substrates were observed for P. aeruginosa wildtype and ferripyoverdine receptor mutants.text/html2013-09-26T07:11:12+01:00http://www.webmedcentral.com/Mr. Mohammadreza SoleimaninanadeganiEvaluation of critical level in Bacillus Cereus growth curve in milk products with different conditions based on experimental data and ComBase Predictive Models
http://www.webmedcentral.com/article_view/4403
Predictive microbiology in food products empowered research application to achieve the high accurate evaluation of microbial risk in food products. According to previous research, Bacillus cereus selected as a serious problem in milk industry; because of the heat resistance characteristics which Bacillus cereus can causes two diverse syndromes of food poisoning (diarrhoea and vomiting), suspected foods contained between 106 and 09 cfu/g. In this study, two methods were used to evaluate, the first one is ComBase - a Combined dataBase for predictive microbiology - a common database on microbial responses to food environments and second one is NeuroXL Predictor (neural network forecasting tool). The study went on the interaction of temperature (6, 7, 8 and 9 °C), pH (6.6, 6.7 and 6.8), according to raw milk pH on the probability of pathogen growth. Thus, Over 74 recorded sample in ComBase remarkable date were collected for comparison. The prediction model showed a good performance for validation data were correctly classified. The predictions indicated an abrupt growth/no growth interfaces occurred at low levels of temperature and pH which could in high risk of production of toxin in milk products (105 cfu/g). text/html2013-09-30T06:06:35+01:00http://www.webmedcentral.com/Dr. Shobha KLBrevundimonas diminuta causing urinary tract infection
http://www.webmedcentral.com/article_view/4411
Objectives: To report urinary tract infection caused by Brevundimonas diminuta and antibiotic susceptibility pattern of this gram negative bacillus.
Patient and methods: Urine from an infant suffering from fever and vomiting suspected of urinary tract infection was analyzed .His blood was also collected for cell count. Isolation and identification of the organism was done from urine sample, followed by antibiotic susceptibility testing of the organism isolated.
Results: Brevundimonas diminuta was isolated from urine specimen. Strain was sensitive to amikacin, imipenem,ticarcillin/clavunalic acid but resistant to ampicillin and ciprofloxacin.
Conclusion: B.diminuta is a rare pathogen and can cause urinary tract infection. The organism is resistant to quinolones and this should be opted out for treatment.
Key words: B.diminuta, ciprofloxacin resistant
text/html2015-04-17T13:15:38+01:00http://www.webmedcentral.com/Dr. Liliana D Godoy OlivaresMicrobiological Analysis of reconfigured rice
http://www.webmedcentral.com/article_view/4832
In Chile, rice industry generates important volumes of by-products of low commercial value. Many of such by-products present nutritional properties similar to those of whole grains and, therefore, the main cause of their little valuation would be the form that conditions their destination. For such a reason, extrusion would be the most appropriate technology to revalue processing rice by-products upon making possible to obtain attractive products with diverse forms, sizes, flavors and colors.
The purpose of this study was to determine the microbiological characteristic of reconfigured rice by extrusion, flavored with garlic, garlic plus fiber, barbecued steak, barbecued steak plus fiber, onion and onion plus fiber.
The results show that according to the microbiological margins established by the Food Sanitary Regulations of Chile (RSA) with those obtained by the reconfigured rice samples, these last do not present danger to the human being.