TEM-145 and TEM-146 &#223-lactamases produced by Escherichia coli isolates from state hospitals in KwaZulu-Natal, South Africa

Two Escherichia coli isolates which were isolated from the urine of patients in state hospitals in KwaZulu-Natal, South Africa were investigated to determine the sequence of the TEM -lactamases responsible for their resistance to -lactamase inhibitors. The isolates were subjected to MICdeterminations, iso-electric focusing analysis, plasmid analysis, polymerase chain reaction (PCR) for the detection of -lactamase genes and sequencing of the blaTEM. Analysis of the nucleotide sequencesrevealed the presence of two novel TEM -lactamases, TEM-145 and TEM-146 which had the R244H mutation. Mutations at position 244 have been previously reported in other inhibitor-resistant TEMs (IRTs)

Detection of mutations in the gyrA of clinical Salmonella spp.

The high prevalence of resistance to nalidixic acid and reduced susceptibility to ciprofloxacin of Salmonella spp. obtained from stool samples of neonates presenting with acute diarrhea in 2001 at the King Edward VIII hospital in Durban, South Africa, prompted this study to determine if there were any mutations in the QRDR of these isolates and to search for the qnrA gene. All isolates with nalidixic acid MICs > 48 μg/ml had the single mutation D87N, or D87G in the QRDR of the gyrA gene, and only 2 strains had an additional mutation; S83L and S83F respectively. The mutation S83T was present in only one isolate with the nalidixic acid MIC of 10 μg/ml whilst the 6 other strains with nalidixic acid MICs < 10 μg/ml had no changes in the QRDR of the gyrA gene. The qnrA gene was not found. These findings indicate that there are mutations in the gyrA of Salmonella isolates which could contribute to resistance to nalidixic acid with reduced susceptibility to ciprofloxacin and there is the co-expression of quinolone and extended-spectrum ß-lactam resistance among Salmonella spp

The effect of mutations in the AmpC promoter region on &#946-lactam resistance from an Escherichia coli clinical isolate in a public sector hospital in KwaZulu-Natal, South Africa

The ampC promoter and attenuator regions of an Escherichia coli clinical isolate from a public hospital in KwaZulu-Natal was investigated to detect the presence of mutations in these regions. The isolate was subjected to MIC determinations, IEF analysis, PCR for the presence of &beta;-lactamases and sequencing of the ampC gene. Analysis of the ampC promoter and attenuator regions of the isolate showed that the isolate had mutations in the promoter region and this included insertions of nucleotides in the spacer region between the -10 and -35 Pribnow boxes. The insertion of an extra nucleotide in the spacer region between the -10 and -35 boxes affects the resistance of bacteria to &beta;-lactam antibiotics

Geographical evolution of the CTX-M &#223-lactamase – an update

The CTX-M- type extended spectrum -lactamases (ESBLs) that preferentially hydrolyze cefotaxime are emerging globally and comprise of more than 50 enzymes. The emergence of novel CTX-M - lactamases in several countries is noted as opposed to the transfer of established CTX-M genes from one country to another, suggestive of a de novo dissemination of CTX-M genes