Extensively drug-resistant New Delhi metallo-β-lactamase–encoding bacteria in the environment, Dhaka, Bangladesh, 2012

Carriage of the New Delhi metallo-β-lactamase variant 1 (NDM-1) enables drug resistance to move between communities and hospitals. In Bangladesh, we found the blaNDM-1 gene in 62% of environmental waters and in fermentative and nonfermentative gram-negative bacteria. Escherichia coli sequence type (ST) 101 was most commonly found, reflecting a common global relationship between ST101 and NDM-1

Analysis of Escherichia coliSTs and resistance mechanisms in sewage from Islamabad, Pakistan indicates a difference in E. coli carriage types between South Asia and Europe

Objectives To discover the Escherichia coli STs and associated resistance mechanisms in the community in Islamabad, Pakistan by analysis of E. coli isolates in sewage. Methods One hundred and ten E. coli were isolated from sewage across the city of Islamabad without antibiotic bias and confirmed as E. coli by MALDI-TOF MS. Isolates were characterized by fumC/fimH (CH) typing and core-genome MLST. Resistance mechanisms, virulence genes, phylotypes and plasmid incompatibility types were determined in a subset of isolates by in silico analysis. The genomic position of blaCTX-M-15 was determined using S1-PFGE, probing and Nanopore MinION sequencing. Results and conclusions The most prevalent STs were ST394, ST10 and ST648, accounting for 39% of all isolates collected and were found at many sites across Islamabad. Carbapenemase genes were absent and only a single isolate of ST131 was found. The most prevalent resistance mechanisms were qnrS1 and blaCTX-M-15, with blaCTX-M-15 penetrating many STs and found in 31% of all collected isolates. However, the majority of the successful STs were blaCTX-M-15 negative indicating that resistance is not the main driver of prevalence. Twenty-three percent of blaCTX-M-15 genes were chromosomally encoded and large ISEcp1-mediated insertions included qnrS1 and several plasmid genes. In all chromosomally encoded isolates no plasmid copies of blaCTX-M-15 were found. The most prevalent ST (ST394) contained many enteroaggregative E. coli virulence genes and the fimH30 variant allele previously linked to the success of ST131

Human carriage of cefotaxime-resistant Escherichia coli in North-East India: an analysis of STs and associated resistance mechanisms

Objectives To determine the prevalence of Escherichia coli STs and associated resistance mechanisms carried by the community in North-East India. Methods E. coli (108) were isolated from sewage collected from 19 sites across the city of Silchar by plating on MacConkey agar with/without selection (50 mg/L cefotaxime). Species identification was confirmed by MALDI-TOF MS for 82 isolates. Common resistance mechanisms were determined by WGS of pooled E. coli isolates. PFGE combined with specific probes determined the presence of common resistance mechanisms in all isolates. Phylotypes, multilocus STs, core-genome multilocus STs, resistance genes and virulence genes were determined by in silico analysis of 38 genomes. Results and conclusions Analysis of isolates collected without selection (n = 33) indicated that cefotaxime resistance in E. coli was 42% (14/33) and estimated meropenem resistance at 9%. The remaining 58% (19/33) were additionally susceptible to ampicillin, trimethoprim, ciprofloxacin and aminoglycosides. The most common ST among the cefotaxime-resistant E. coli was ST167 (29%), followed by ST410 (17%) and ST648 (10%). E. coli ST131 was absent from the collection. Sixty-three isolates were resistant to cefotaxime and harboured blaCTX-M-15 [54% (34/63)] or blaCMY-42 [46% (29/63)], of which 10% (6/63) harboured both genes. Carbapenem resistance was due to blaNDM-5, found in 10/63 cefotaxime-resistant isolates, and/or blaOXA-181, found in 4/63 isolates. NDM-5 was encoded by IncX3 and/or IncFII plasmids and CMY-42 was mostly encoded by IncI plasmids. NDM-5 appears to have replaced NDM-1 in this region and CMY-42 appears to be in the process of replacing CTX-M-15

An evaluation of methods used to assess fat cover in live cattle

[Summary]: Five methods of assessing subcutaneous fat cover were compared using male and female Bos indicus - Bos taurus beef cattle. None of the methods was able to accurately predict fat depth. The ESTD FAT technique has the greatest potential because it requires minimal handling. Use of the TRANS site may assist to improve accuracy with the ESTD FAT technique

A tactile method modified to assess the finish of beef cattle in marketable condition in north Queensland

Three methods of assessing the fat finish of marketable beef cattle were compared using Bos indicus crossbred cattle. The methods were: the Queensland Livestock Market Reporting Service, the National Beef Recording Scheme and a modified tactile method (MT) of the Meat and Livestock Commission. None of the three methods was able to predict accurately the fat depth at the 13th rib of the carcass. The highest correlation between finish score and fat depth was r = 0.568 for one operator using the MT method. However, wehn data from the MT method were examined it was found that mean fat depth at the 13th rib increased (P<0.05) with increasing finish score in two of the three liveweight categories studied. It is suggested that scoring individual animals on finish is no more accurate than weighing and allocating them to finish categories on the basis of liveweight

Genetic and biochemical characterization of a novel metallo-beta-lactamase, TMB-1, from an Achromobacter xylosoxidans strain isolated in Tripoli, Libya

An Achromobacter xylosoxidans strain from the Tripoli central hospital produced a unique metallo-β-lactamase, designated TMB-1, which is related to DIM-1 (62%) and GIM-1 (51%). bla was embedded in a class 1 integron and located on the chromosome. The TMB-1β-lactamase has lower k values than both DIM-1 and GIM-1 with cephalosporins and carbapenems. The K values were more similar to those of GIM-1 than those of DIM-1, with the overall k /K values being lower than those for GIM-1 and DIM-1. Copyrigh

Genetic and biochemical characterization of an acquired subgroup B3 metallo-β-lactamase gene, blaAIM-1, and its unique genetic context in Pseudomonas aeruginosa from Australia

Three clinical Pseudomonas aeruginosa isolates (WCH2677, WCH2813, and WCH2837) isolated from the Women's and Children's Hospital, Adelaide, Australia, produced a metallo-β-lactamase (MBL)-positive Etest result. All isolates were PCR negative for known MBL genes. A gene bank was created, and an MBL gene, designated bla, was cloned and fully characterized. The encoded enzyme, AIM-1, is a group B3 MBL that has the highest level of identity to THIN-B and L1. It is chromosomal and flanked by two copies (one intact and one truncated) of an ISCR element, ISCR15. Southern hybridization studies indicated the movement of both ISCR15 and bla within the three different clinical isolates. AIM-1 hydrolyzes most β-lactams, with the exception of aztreonam and, to a lesser extent, ceftazidime; however, it possesses significantly higher k values for cefepime and carbapenems than most other MBLs. AIM-1 was the first mobile group B3 enzyme detected and signals further problems for already beleaguered antimicrobial regimes to treat serious P. aeruginosa and other Gram-negative infections

Global Emergence of Trimethoprim/Sulfamethoxazole Resistance in Stenotrophomonas maltophilia Mediated by Acquisition of sul Genes

The first sul2 genes have been found in S. maltophilia from several different countries