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
To evaluate the recent changes in bacteria causing spontaneous bacterial peritonitis [SBP] in cirrhotic patients and its clinical significance on treatment, we compared the etiologic agents and their antibiotic resistance profiles over a four year period. In the prospective period of the study, 150 ascitic fluid [AF] samples obtained from SBP patients admitted consecutively to the Hepatology Department of Theodor Bilharz Research Institute during 2006-2007 were examined for polymorphnuclear leukocytes [PMLs] by blood cell counter and by a bedside dipstick test [Multistix SG10, Bayer]. Blood and AF cultures were performed using BACTEC blood culture bottles and purified bacterial isolates were identified with a BBL Crystal Id System and software. Antibiotic sensitivity testing and extended-spectrum beta-lactamase [ESBL]- production were determined by disk diffusion and modified double disk synergy tests [MDDST] respectively. Genes encoding ESBLs were detected by PCR and typed by DNA sequencing. In the retrospective period of the study [2004-2005], the laboratory records of 140 episodes of SBP were examined for the culture positive rate, causes of SBP and their antibiotic resistance patterns recorded. Results showed that the overall culture positivity rate was significantly higher in prospective study period [32%] versus retrospective period [16.4 %] p<0.05 and the main bacterial isolates were E.coli, 47.8% and Klebsiella pneumoniae, 28.1% with no differences in the two study periods. Gram positive bacteria [GPB] were isolated more frequently in the prospective than retrospective period [25% versus 13%]. Two opportunistic bacterial species [Staphylococcus haemolyticus and Pantoea agglomerans] were detected as a cause of SBP in the prospective period. Species identification of Pantoea isolate was confirmed by DNA extraction, sequencing of ribosomal RNA and phylogenetic analysis. ESBLs were detected among 17.6% of E. coli and Klebsiella isolates of the prospective period and all were of the CTX-M15 type. The rate of resistance to cefotaxime significantly increased from 45% to 72 % and to ciprofloxacin from 25% to 47% and treatment failure rate was 65% in recent years. No resistance was detected to imipenem over the entire study period. For the GPB, 50% were resistant to ampicilin/sulbactam, cefotaxime and gentamicin and one S. haemolyticus isolate was methicillin resistant. In conclusion the emergence of multidrug resistant opportunistic pathogens and ESBL-producing E. coli and Klebsiellae as causal agents of SBP, together with an increase in resistance to antibiotics commonly used for the empiric treatment of bacterial peritonitis have serious implications on patient management in our region. Rapid diagnosis of SBP by a bedside dipstick test and identification of the causative organism by culture using blood culture bottles and direct sensitivity testing to establish an effective antibiotic therapy is recommended
ABSTRACT
Candiduria is a common and high risk event in patients with uropathies and cancer. In this study we investigated the distribution of 3 virulence factors namely: biofilm formation [BF], secreted aspartyl proteinase [SAP] and phospholipase activity [PLA] among different Candida species isolated from inpatients with candiduria. The susceptibility patterns of Candida isolates to antifungal agents, including the new voriconazole, were evaluated in vitro and the association of these virulence factors with resistance was studied. Urine specimens from 250 patients divided into 3 groups were examined: Group1 [n=50] cancer bladder; Group2 [n=100] obstructive uropathy and Group 3 [n=100] simple recurrent urinary tract infection [UTI]. Candida isolates were identified by CHROM-agar, and by Candifast Es Twin test. Susceptibility testing to antifungal agents was evaluated by disc diffusion test using fluconazole [FCZ] 30microg discs and E test strips for Minimum inhibitory concentration [MIC] determination of FCZ, voriconazole [VCZ] and Amphotericin B [AMB]. Assessment of BF was performed by tube and spectrophotometric plate adherence methods and quantitated by crystal violet staining and XTT reduction assays. PLA was screened using Sabouraud egg yolk agar and SAP was detected using bovine serum albumin agar [BSA]. The overall prevalence of candiduria was 24% with highest incidence among obstructive uropathy patients [67.2%]. Isolation rate of Candida [C]. nonalbicans species [C. tropicalis ,C. krusei and C. glabrata] was significantly higher than C. albicans [73.1% versus 26.8%; p256microg/ml]. Voriconazole, the new triazole antifungal agent, was active against all isolated Candida species with a sensitivity rate of 82%-100% and low MIC values [0.064-1microg/ml] except in C. glabrata species [22%]. All isolated Candida species were more sensitive to VCZ compared to FCZ; particularly C. krusei isolates [90% versus 9%]. AMB remained to be an effective drug with absolute sensitivity and low MIC
ABSTRACT
SEN virus [SENV] has been tentatively linked to transfusion-associated non A-E hepatitis. The aim of the present study was to determine the prevalence of SENV among Egyptian patients with HCV-related chronic liver disease [CLD] and haemodialysis [HD] patients and to assess the clinical effect of SENV infection on coexistent hepatitis C either in the severity or the probability of developing hepatocellular carcinoma [HCC]. Polymerase chain reaction [PCR] was used to detect SENV-D and SENV-H DNA in serum samples of 74 HCV-related CLD patients, 45 uraemic patients on maintenance HD and 28 healthy controls. SENV DNA was detected in 13.5%, 11.1%, and 7.1% of CLD, HD patients and healthy controls respectively with no significant differences between patients and control group. No statistically significant differences were demonstrated between SENV infected and non infected CLD or haemodialysis patients regarding the clinical and biochemical parameters. SENV infection was significantly higher in CLD patients with HCC [33.3%] than without [8.5%] [p<0.05]. In conclusion, SENV does not seem to be a common infection in Egyptian patients. It has no apparent influence on the severity of co-existent HCV related CLD but it could be a risk factor for developing HCC in these patients. Further studies are needed to define the aetiopathogenic role of SENV infection in HCC development