No abstract

The ESBL-producing E. coli in carriers can cause UTIs.

The detection rate of CTX-M-type β-lactamase-producing Enterobacteriaceae in Japan has significantly increased. Nursing homes may be a reservoir of antibiotic-resistant bacteria. Therefore, we determined the prevalence of, and risk factors associated with, fecal carriage of CTX-M-type β-lactamase-producing Enterobacteriaceae among nursing home residents. A total of 225 stool samples were collected for phenotypic and genotypic identification of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. Multivariate analysis was performed to identify the risk factors associated with fecal carriage of CTX-M producers. The prevalence of CTX-M-type ESBL-producing Enterobacteriaceae, as confirmed by phenotypic and genotypic methods, was 19.6% (44 of 225 samples). Escherichia coli was the predominant CTX-M-type ESBL-producing bacterium among these isolates (41 of 44 isolates). Genotyping of blaCTX-M gene-positive isolates showed that 30 (68.2%), 13 (29.5%), and 1 (2.3%) of 44 samples belonged to groups CTX-M-9, CTX-M-1 and CTX-M-2, respectively. Among the CTX-M-type ESBL-producing Enterobacteriaceae found in nursing homes, 95.5% (42 of 44 isolates) were co-resistant to quinolone antibiotics. In multivariate logistic regression analysis, inability to turn over in bed, diabetes, and invasive procedures within the last 2 years were the only variables independently associated with fecal carriage of CTX-M-type ESBL producers. Nursing home residents in Japan exhibit a high prevalence of CTX-M-type ESBL-producing Enterobacteriaceae carriage, with a high level of co-resistance to quinolones.

CagA, especially East Asian type, is one of the most important virulence factors of Helicobacter pylori, which is believed to contribute to the gastric cancer development. There is extreme sequence heterogeneity on 3' region of cagA gene, demonstrated by the sequence analysis of cagA of H. pylori strains isolated from gastric disease patients. However, whether such heterogeneity of the cagA gene sequence is related to the pathogenicity of H. pylori in the gastric cancer development is not certain. Therefore, in this study, the 3' region of cagA sequences isolated from asymptomatic healthy individuals in Japan and Thailand, which show high and low gastric cancer prevalence, respectively, were analyzed and compared with those from patients with gastric cancer. The CagA sequences analysis in 21 and 12 H. pylori DNA samples obtained from Japanese and Thai individuals, respectively, by the molecular phylogenetic method showed that the sequences were more conserved in the Thai individuals (concordance rates among Thai sequences, 93.9-100%) than in the Japanese individuals (concordance rates among Japanese sequences, 82.8-100%) as shown by unrooted neighbor-joining (N-J) consensus trees constructed with the sequence between Asn869 and Ala967 in CagA. CagA sequences in gastric cancer patients were obtained from published data; analysis of these sequences revealed that CagA sequences from almost all Thai individuals were concentrated in one branch. In contrast, CagA sequences from Japanese individuals were uniformly distributed throughout the N-J consensus tree. These results suggest that the difference in the CagA sequences between asymptomatic healthy Japanese and Thai individuals may be linked to the incidence of gastric cancer in Japan and Thailand.