Vancomycin-resistant enterococci (VRE) isolates isolated in Rajavithi Hospital between 1999 and 2009.

From 1999 to 2009, a total of 10,470 clinical enterococcal strains from patients in Rajavithi Hospital were isolated. Of these, 201 (1.9%) vancomycin-resistant enterococci (VRE) including 199 (99.0%) Enterococcus faecium and 2 (1.00%) Enterococcus faecalis were found. The incidence of VRE was 1.8% in 1999, 3.3% in 2000, 5.1% in 2001, 1.0% in 2002, 0.0% in 2003 and 2004, 1.1% in 2005, 4.7% in 2006, 1.9% in 2007, 2.2% in 2008 and 0.9% in 2009. Seventy-one VRE isolates were classified to VanA phenotype (69 VanA E. faecium and 2 VanA E. faecalis) and 130 were classified to VanB phenotype (VanB E. faecium). The rate of inpatient departments (IPD)-associated VRE (199 (99.0%) VRE isolates) was significantly greater than the incidence of outpatient departments (OPD)-VRE (2 (1.0%) VRE isolates). VRE were found in medical (33.7%), ICUs (15.6%) and surgical (15.1%) wards. VRE were mostly found in urine, 64.2%, following in pus, blood, genital and sputum specimens, 21.9%, 9.0%, 3.5% and 1.4%, respectively. VRE, especially vancomycin resistant E. faecium, were multidrug-resistant (resistance to ampicillin, tetracycline, norfloxacin, ciprofloxacin, erythromycin and gentamicin). All strains of VRE were fully susceptible to linezolid.

Bartonella henselae: first reported isolate in a human in Thailand.

This is the first reported case of bacillary angiomatosis associated with Bartonella henselae in Thailand. The clinical, pathological, and microbiological findings are presented. The bacterium was isolated from a biopsy of skin lesions obtained on admission and identified by cellular morphology, characteristics of colonies on chocolate agar, extensive biochemical tests and 16S ribosomal DNA sequencing.

Comparison of media and antibiotic supplements for isolation of Helicobacter pylori from gastric biopsies.

Our objective was to improve the media and the antibiotic supplements in order to increase the detection rate of Helicobacter pylori from gastric biopsy specimens. For the primary isolation of H. pylori taken from gastric biopsies, we compared the efficacy of two media: Columbia blood agar (CBA, Difco); brain heart infusion agar (BHIA, Difco); and two antibiotic supplement sets--a commercial antibiotic supplement (SR147, Oxoid) and an in-house antibiotic supplement (IHS). Gastric biopsies obtained from 210 patients were diagnosed by culture, rapid urease test (RUT) and histology. The true positive criteria were defined as a culture or both urease and histology tests being positive. The H. pylori infection rate was 44.3% (93/ 210). To compare the two media, a total of 106 gastric biopsies were plated on CBA or BHIA with 7% human blood, containing the antibiotic supplement SR147 and incubated under microaerophilic conditions. Of the 106 samples, 48 (45.3%) case of H. pylori infection, compared to the true positive criteria. The isolation rate using a combination of the two media was 83% (40/48). Of the 40 samples, 36 (90%) and 35 (87.5%) were positive on CBA and BHIA, respectively. To compare the two antibiotic supplement sets, a total of 104 gastric biopsies were plated on CBA, containing the commercial antibiotic supplement SR147 (5 mg/l trimethoprim, 10 mg/l vancomycin, 5 mg/l amphotericin B and 5 mg/l cefsulodin) or containing IHS (5 mg/l trimethoprim, 10 mg/l vancomycin, 2 mg/l amphotericin B and 2,500 U/l polymyxin B). Of the 104 samples, 45 (43.2%) case of H. pylori infection were found compared to the true positive criteria. The isolation rate using a combination of the two selective supplement sets was 82% (37/45). Of the 37 samples, 35 (95%) and 34 (92%) were positive with SR147 and IHS, respectively. Our study indicates that the combination of the two media and two antibiotic supplements is useful for maximum recovery of H. pylori isolated from gastric biopsies. CBA, and the commercial antibiotic supplement SR147 provided higher detection rates for H. pylori than BHIA, and IHS but the differences were not statistically significant.