ABSTRACT
High prevalence of infections caused by extended-spectrum beta-lactamase [ESBL]-producing isolates, notably Escherichia coli, has been suggested in Egypt. As little is known about the genetic background of these isolates, ESBL-positive E. coli isolates obtained among 520 Enterobacteriaceae prospectively collected [May 2007 -August 2008] from inpatients [n=320] and outpatients [n=200] seen at the Theodor Bilharz Research Institute [Cairo], were characterized. Clinical epidemiology, antibiotic susceptibility, and genetic traits including bla gene, phylogenetic group, ERIC-2 PCR profile, multilocus sequence type [ST] were determined. Among the 520 collected Enterobacteriaceae, were 291 [56%] E. coli and 165 [32%] Klebsiella pneumoniae. A total of 16% of all Enterobacteriaceae were ESBL-producers: 19% in E. coli and 14% in K. pneumoniae. Of the E. coli ESBL-producers, 75% [n=41] were isolated from urine. Rates of ESBL producers did not differ significantly between in and outpatients for E. coli [20 vs 17%] but significantly for non E. coli ESBL producers [18.5 vs 1.2 %: p= 0.0001]. CTX-M-15 was identified in all ESBL producers. Of the E. coli ESBL producers, 40% belonged to phylogenetic group A, 32% to D and 26% to B2. The ERIC-2 PCR method showed genetic background diversity with clusters in each group having profiles indistinguishable to that of previously published clones: complex ST10 and ST131. MLST showed that 75% of E. coli group B2 belonged to clone ST131 and 15% to clones previously detected worldwide, ST73 and ST405. This study illustrates the dissemination of different E. coli clones producing CTX-M-15 in Africa, notably in outpatients
ABSTRACT
The cag pathogenicity island [cagPAI] is one of the major virulence determinants of Helicobacter pylori [H. pylori]. Acquiring virulent strains of H. pylori is associated with increased risk for the development of gastric ulcers or cancer. The aim of this study was to determine H. pylori cagPAI genes pattern among dyspeptic Egyptian patients and its correlation with the varying degrees of the associated chronic gastritis. Histopathological examination, urease test and polymerase chain reaction [PCR] assay were performed for gastric antral biopsies obtained from 106 dyspeptic patients undergoing upper endoscopy. DNA extracts from H. pylori positive cases were analyzed for the presence of cagPAI genes cagA, cagE, cagM, tnpA, tnpB and cagT by using PCR assay. Apparently normal gastric mucosa was seen on endoscopy in 30.2% of dyspeptic patients while gastritis was diagnosed in 69.8% with significant difference [p<0.05]. H.pylori was detected in 71.7% of dyspeptic patients. A strong association was observed between H. pylori infection and gastritis patients [p<0.01]. The positivity rate of any of the cagPAI genes were 65.8% of H. pylori positive cases. Analysis of the entire cagPAI genes revealed that both cagA and cagE were the most predominant genes [30.2% , 18.4% respectively]. cagT and tnpB genes were not detected in all H. pylori positive gastric biopsies. The presence of the entire cagPAI genes was more substantiated in gastritis patients than in those with apparently normal mucosa [p<0.05]. The presence of cagA1/2, cagA3/4, cagM and cagE genes were significantly associated with moderate degree of gastritis [p<0.02], while tnpA gene was mostly detected in marked degree of gastritis [p<0.02]. In conclusion, it can be admitted that infection with virulent strain carrying cag PAI genes may be an indication of the risk of progression of gastric mucosal damage in chronic gastritis patients. In such country as Egypt where there is a high prevalence of H. pylori infection, cagPAI genotyping is important for prediction of the clinical outcome in H. pylori related gastritis aiming at eradication of infection before the progression to severe gastroduodenal diseases
ABSTRACT
This study was designed to assess the significance of pyuria as a marker of urinary tract infections [UTIs] in haemodialysis patients and renal tuberculosis as a common a etiology of sterile pyuria. The study was conducted on 50 patients with end stage renal disease [ESRD] on regular haemodialysis [group I], as well as 10 healthy controls [group II]. Fresh urine samples were cultured, examined microscopically for pyuria and tested by Bayer reagent strips for protein, blood, nitrite and leucocyte esterase [LE]. Gram stain of colonies and their identification to the species level using API 20 E system were performed. Ziehl-Neelson [ZN] staining for acid alcohol fast bacilli and Polymerase chain reaction [PCR] for detection of Mycobacterium tuberculosis [MTB] DNA were performed on 24 hours collected urine samples. All patients had pyuria [>/= 5 WBCs/hpf]. Protein, blood, LE and nitrite were significantly higher in patients than in controls [P value <0.01, <0.01, <0.001 and <0.05 respectively]. A significant correlation was found between patients' symptoms and bacterial growth [p<0.1]. Thirty one patients had sterile pyuria; three out of them [10%] were proved to be tuberculous by ZN or PCR. To conclude, pyuria is a common finding in haemodialysis patients and is proved to be a valuable parameter of UTIs in these patients. In symptomatic patients with sterile pyuria, renal tuberculosis should be excluded by ZN staining and/or PCR. In asymptomatic patients, periodic urine culture should be performed to confirm presence or absence of UTIs
ABSTRACT
Recent epidemiological studies have implicated Cytomegalovirus [CMV] infection in the etiology of cancer bladder. The present study was designed to estimate the performance characteristics of different assays, used for identification of CMV infection in schistosomal patients. The study was conducted on sixty cancer bladder patients; thirty five with schistosomiasis [group I] and twenty five without [group II], and twenty control subjects were included [group III]. PCR technique for detection of CMV DNA was performed on bladder tissue, serum, buffy coat and urine. ELISA for detection of IgG and IgM in sera and Antigenemia test and electron miscroscopic studies [EMS] on buffy coat were performed. CMV DNA was significantly detected in group I versus group II by PCR on bladder tissue, buffy coat, and serum respectively. None of the urine samples were positive for CMV DNA. The results of different assays were evaluated in relation to PCR results on tissue biopsies. Antigenemia test showed significant difference between group I versus group II. The EMS was found to increase the sensitivity of PCR on bladder tissue. Both PCR on serum and antigenemia test showed similar sensitivity of 56%, but a specificity of 100% and 81% respectively. In conclusion, the significant association of CMV infection with cancer bladder in Egyptian patients, suggest that the virus may be implicated in the development of such malignant transformation especially in cases with schistosomal affection. Both pp65 antigenemia assay and PCR on serum are two major assays available for diagnosis and monitoring of CMV infections. The EMS could increase the sensitivity and accuracy of PCR on bladder tissue and on buffy coat. Further investigation on a larger number of patients are required in immunodeficient schistosomal cancer bladder patients in order to clarify the role played by CMV in bladder cancer
ABSTRACT
Increased expression of inducible nitric oxide synthase [iNOS] has been observed in patients with chronic inflammatory diseases of the gastrointestinal tract leading to sustained production of nitric oxide [NO] which may induce DNA damage. Since Helicobacter pylori [H. pylori] infection produces a state of chronic immunostimmulation in the gastric epithelium and a causal relationship between H. pylori CagA+ strains infection and gastric cancer has been suggested, therefore, our aim was to evaluate the significance of iNOS expression in gastric lesions induced by H. pylori CagA+ strains with correlation to the encountered endoscopic and pathological diagnoses. Eighty four dyspeptic patients underwent endoscopic examination. Four antral gastric biopsies were obtained for detection of H. pylori by histopathological assessment [Giemsa staining], urease test and gene expression of H. pylori using PCR assay. Immunohistochemical staining for iNOS expression and quantitative detection of anti-CagA antibodies were performed. It was found that H. pylori infection was detected in 64.3%, CagA seropositivity in 54.8% and iNOS expression in 61.9%. Anti-CagA antibodies seropositivity and iNOS immunoexpression were significantly related to H. pylori infection. The positive rates of iNOS immunostaining increased with the lesion progression from chronic superficial gastritis to chronic atrophic gastritis to intestinal metaplasia [45.2%, 87.5% and 92.8% respectively]. Positive immunostaining rates of iNOS correlated significantly with H.pylori Cag A seropositivity with respect to both endoscopic and pathologic diagnoses. In conclusion, CagA+ H. pylori strains are associated with enhanced immunoexpression of iNOS in H. pylori-related gastric diseases, therefore they might contribute as risk cofactors that conduces to gastric carcinogenesis. Given the high prevalence of H. pylori gastric diseases and frequent performance level of endoscopic gastric examinations among Egyptian patients, prompt identification of gastric infections caused by H. pylori harboring Cag A virulence factor is necessary for the early eradication of infection before the development of pre-neoplastic lesions