ABSTRACT
Urinary tract infections [UTIs] are the most common cause of nosocomial infection and up to 80% of UTIs are associated with the use of urinary catheter. Inappropriate use of this device may lead to an increase incidence of infectious complications. It has been estimated that 65 % of nosocomial infections are biofilm associated urinary tract infections, loading the health care system enormous costs. These biofilm infections are 10 to 1000 times more resistant to the effects of antimicrobial agents. In this study urine samples were collected from 150 patients with CAUTI [group 1] giving one hundred and fifty bacterial isolates and 70 non catheterized UTI patients [group 2] giving fifty bacterial isolates. Out of the two hundred isolates the most common isolated pathogens were: Escherichia coli[E.coli] [50%] in group I, [48%] in group 2, followed by Klebsiella [26.7%] in group J, [28%] in group 2, pseudomonas aeruginosa [8%] in group 1, [12%] in group 2 then Staphylococcus aureus [8.6%] in group 1, [4.%] in group 2, Proteus [4.6%] in group 1, [4%] in group 2, and lastly, Candida albicans [2%] in group 1,[4. %] in group 2. The E.coli isolates were evaluated for biofilm formation using congo red agar [CRA] and microtitre plate methods. Out of 99 E.coli isolates; 27 were non biofilm forming in group 1, 19 isolates in group 2 while 48 isolates were biofilm forming in group 7, only 5 isolates in group 2 . Using microtitre plate method; out of 48 biofilm forming isolates in group 1; 8 isolates [16.6%] were weak biofilm forming, 10 [20.8%] were moderate biofilm and 30 isolates [62.5%] were strong biofilm forming while, 3 isolates were weak biofilm forming in group2. The two methods used to detect biofilm formation [CRA test and spectrophotometer], both are valid tests. CRA is simpler but spectrophotometer differentiates between weak and strong biofilm producers
ABSTRACT
Background: staphylococcus enterotoxins [SEs] are super antigenic toxins responsible for food poisoning in human and lead to high incidence of food poisoning outbreaks. The only previously known toxins were the five major classical types SEA to SEE. New types have been identified such as SEG and SEH. Objective: The aim of this work was to evaluate the percentage of S. aureus and enterotoxin productivity in milk and some dairy products, and to characterize the genes encoding some of the classical and the most newly described types of SEs
Materials and methods: 400 samples [200 milk, 100 ice-cream and 100 kariesh cheese samples] in addition to 50 human nasal swabs from handlers of these products were collected from different localities in Assiut Governorate, Egypt and were examined for the presence of S. aureus strains using Baird-Parker agar[BP-A]. Suspected colonies were confirmed as S. aureus by tube coagulase test and detection of clumping factor, protein A and capsular polysaccharides by latex agglutination test. Confirmed S. aureus isolates were examined for the production of SEs by using sodium dodecyl sulphate-polyacrylamide gel electrophoresis [SDS-PAGE]. Enterotoxigenic strains were examined for the presence of SE genes by polymerase chain reaction [PCR] using specific primers for SEA, SEB, SEC, SED, SEG and SHE
Results: confirmed S. aureus isolates were detected in 50% of raw milk, 35% of ice-cream and 65% of kariesh cheese samples and 40% of nasal swabs. Collectively, 50% of S. aureus isolates were enterotoxigenic and the highest percentages were detected in milk taken directly from animals [68. 7%] and kariesh cheese from street distributers [65. 7%]. In milk and dairy products, the major classical enterotoxin genotype was SEA which was detected in 29.3% of toxigenic isolates. SEC was detected in 16.1% and SED in 10.1%. SEB could not be detected. For the newly described genes, SEG was detected in 10.1% and SEH in 7.1%. Mixed forms were found in 2 3.2% of toxigenic isolates and four strains [4. 04%] carried undescribed genes. In nasal swabs, the most common type of SEs was SEA [40%] other types except SEB were detected separately in 10% of toxigenic isolates. The mixed forms were found in 20% of toxigenic isolates
Conclusions: a large proportion of raw milk and some dairy products [especially kariesh cheese] exposed for sale in Assuit City, Egypt are contaminated with enter toxigenic S. aureus. The most common type in both milk and dairy products as well as in nasal swabs was SEA which is known to be less common among strains from animal origin than from human. Nasal carriage in human food handlers is considered a primary source of contamination of milk and dairy products
ABSTRACT
Background: Group A rotavirus has been recognized as a leading cause of severe diarrheal disease in infants and young children worldwide and accounts for 20-25% of children diarrheal deaths per year. Defining the viral agents related to diarrhea will assist in providing an accurate estimate of disease burden within a community and will also be useful to assess the impact of vaccination whenever they become available. Epidemiological and molecular studies in many countries show complex patterns of change from year to year in the genotype of rotaviruses that cause diarrhea in children from the same geographical area. These data can be useful to select areas for vaccine trials and to serve as a baseline for identification of new strains, should they emerge
Objectives: To investigate the role of group A rotavirus in acute diarrhea among infants and children under three years of age attending or admitted to Assiut Pediatric University Hospital and to compare between the strip test and Enzyme Immune Assay [EIA] in diagnosis of rotavirus infection using the Reverse Transcriptase-Polymerase Chain Reaction [RT-PCR] as a gold standard, beside defining the genotype of the detected strains using multiplex-PCR
Methods: 88 children under the age of three years, presenting with acute diarrhea to Assiut Pediatric University Hospital between December 2005 and April 2006, were examined for group A rotavirus antigen in stool by a quick strip test and EIA. RT-PCR was also performed as a reference test. Twelve children of matched age and sex, without diarrhea, were also included [control group]. All rotavirus positive samples by RT-PCR were also subjected to genotyping by multiplex PCR using a cocktail of primers specific for the most common genotypes of rotavirus in human [G1, G2, G3, G4, G8 and G9]
Results: Out of the 88 patients, 33 were rotavirus positive by strips [37.5%], 42 were rotavirus positive by EIA [47.7%] and 44 were positive by RT-PCR [50%]. All control samples were negative by the three methods. 28 samples were positive by both strips and EIA and 44 samples were negative by both methods, whereas discordant results were obtained in 19 samples. Using the RTPCR as a reference test, it was found that the strips failed to detect 13 out of 44 positive samples, while the EIA failed to detect nine out of these 44 positive samples. The sensitivity and specificity of strips versus RT-PCR were 70.5% and 95.5%, respectively, whereas those of EIA were 86.4% and 91%, respectively. Genotyping by multiplex PCR revealed that all the detected strains belong to G3 genotype
Conclusion: The rate of infection with group A rotavirus among children with acute diarrhea differs according to the method used for detection [37.5% by strips, 47.7% by EIA and 50% by RTPCR]. The strips are more rapid, simple and specific than EIA, yet the EIA remains more sensitive in detecting rotavirus antigen in stool. All rotavirus strains detected belong to G3 genotype