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T he rapid and extensive dissemination of CTX-M-type extended-spectrum ␤-lactamases (ESBLs) in humans, animals, and the environment is one of the most successful stories of microbial drug resistance (1). CTX-M ␤-lactamases were originally named for their substrate preference for cefotaxime over ceftazidime (2), but subsequent microevolution means that many of the 140 variants currently listed (as of June 2013) at http://www.lahey.org /studies/other.asp#table1 confer resistance to both cefotaxime and ceftazidime (3, 4). CTX-M variants can be divided into six clusters (CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9, CTX-M-25, and KLUC, with Ͻ90% identity between clusters and Ͼ95% identity within clusters) (1, 5, 6). CTX-M-1 and CTX-M-9 group enzymes are the most frequently reported groups worldwide, and CTX-M-15 and CTX-M-14, respectively, are the most common variants within these groups (4, 6). In 2010, CTX-M-64, a chimera of the CTX-M-1 (N-and C-terminal domains) and CTX-M-9 (central domain) group enzymes, was identified in Japan (7) and then China (8), and a similar chimeric protein, CTX-M-132, was also recently reported in Escherichia coli from a chicken carcass in China (GenBank accession no. JX313020) (Fig. 1). Here, we have identified bla CTX-M-123 , a third hybrid of bla CTX-M-1 and bla CTX-M-9 group genes.Two E. coli isolates were obtained from the feces of diseased animals, FKP358 (pig) in Guangdong Province in December 2010, and AHC4 (chicken) in Anhui Province (ϳ1,200 km from Guangdong Province) in June 2011. Multilocus sequence typing (MLST) (http://mlst.ucc.ie/mlst/dbs/Ecoli) identified AHC4 as sequence type 746 (ST746) and FKP358 as ST165. Both isolates were resistant to most ␤-lactams, including ceftazidime and cefquinome (Ͼ64 g/ml), but were susceptible to imipenem and cefoxitin (Table 1). PCR screening for selected bla genes (bla TEM , bla SHV , bla CTX-M , and bla CMY-2 ) (8, 9), plasmid-mediated quinolone resistance (PMQR) genes, including oqxAB (10), and fosfomycin resistance (fos) genes (11) revealed bla CTX-M , bla TEM , fosA3, and oqxAB in FKP358 and bla CTX-M in AHC4.Broth mating with E. coli C600 (streptomycin resistant; MIC, Ͼ2,000 g/ml) and selection on cefotaxime (2 g/ml) and streptomycin (2,000 g/ml) gave transconjugants from AHC4 only, carrying two plasmids of ϳ90 kb (pHNAH4-1) and Ͻ5 kb (pHNAH4-3). Hybridization with a probe generated by digoxigenin (DIG) High Prime DNA labeling (Roche, Germany) of the amplicon generated with primers M123-F and M123-R (see Table S1 in the supplemental material) indicated that the bla CTX-M gene is on pHNAH4-1. Transformation into E. coli DH5␣ with selection on cefotaxime (2 g/ml) gave transformants carrying a single ϳ60-kb plasmid with bla CTX-M from AHC4 (pHNAH4-2) and a single ϳ90-kb plasmid with bla CTX-M , bla TEM , and fosA3 from FKP358 (pHNP358).Complete sequencing of bla CTX-M genes amplified using primers designed from the typical context of bla CTX-M-1 group genes (see Table S1 in the supplemental material) revealed bla CTX-M-55 in pHNAH4-2 and a nove...

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Of the 12 serotypes present, the majority of isolates were not contained in PCV7 (the 7-valent pneumococcal conjugate vaccine), including 1 isolate that was serotype 1, 12 isolates that were serotype 2, 58 isolates that were serotype 5, 7 isolates that were serotype 7F, and 1 isolate that was serotype 12F. To determine whether clonal dissemination of the predominant serotypes had taken place, genotyping was performed on 100 S. pneumoniae isolates by using two methods: pulsed-field gel electrophoresis (PFGE) of SmaI-digested genomic DNA, and the Bacterial Barcodes repetitive-element PCR (rep-PCR) method. Criteria for delineating rep-PCR genotypes were established such that isolates of different serotypes were generally not grouped together. The two methods were equally discriminatory within a given pneumococcal serotype. PFGE separated the isolates into 15 genotypes and 7 subtypes; rep-PCR separated isolates into 15 genotypes and 6 subtypes. Using either method, isolates within serotypes 2, 5, and 7 formed three large, separate clusters containing 1 genotype each. Both methods further distinguished related subtypes within serotypes 2 and 5. Interestingly, one of the PFGE subtypes of serotype 5 is indistinguishable from the Columbia 5 -19 clone circulating in Latin America since 1994. The data support that serotypes 2 and 5 were likely to be the result of dissemination of particular clones, some of which are responsible for invasive disease over a broad population range.

Background: Proteus mirabilis is one of the organisms which is often associated with urinary tract infections of humans as well as animals. As a member of Enterobacteriaceae family, the level of antimicrobial resistance tend to pose a significant public health risk. Hence, the present study was undertaken to study antibiogram profiles, multidrug resistance P. mirabilis isolates and detection of β-lactamase activity in them.Methods: A total of 175 P. mirabilis isolates from different sources were subjected to antibiotic sensitivity/ resistant test by Kirby Bauer disc diffusion method. Detection of ESBL production was done phenotypically by Phenotypic Screening Test and Phenotypic Confirmation Test as recommended by CLSI guidelines and genotypically using multiplex PCR assay to detect different classes of β-lactamase genes. This study was carried out from March 2017 to August 2018 in and around areas of Krishna District Andhra Pradesh.Result: Out of 175 P. mirabilis isolates screened, antibiogram revealed highest sensitivity towards gentamicin (76.57%), followed by ampicillin (64.57%), kanamycin (61.14%), amikacin (60.57%) and streptomycin (43.42%). Higher resistance was observed for erythromycin (71.42%), nalidixic acid (62.85%), ciprofloxacin (62.85%), tetracycline (60%), polymyxin-B (60%), cefoxitin (49.14%) and amikacin (36%). β-lactamase genes were detected in a total of 23 isolates (13.14%). Prevalence rates of β-lactamase genes among different samples was 23.6%, 11.1%, 10.8% and 42.8% from chicken, pork, poultry cloacal swabs and human urine samples, respectively with blaTEM being the predominant gene detected (69.56%) followed by blaOXA (26.08%), blaAmpC gene FOX (13.04%), blaCTX-M group I (4.34%), blaSHV (4.34%) and blaAmpC gene CIT (4.34%) among all the tested P. mirabilis isolates.

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