The ampicillin resistance of clinical isolates of Shigella sonnei is due to beta-lactamase production. Two kinds of resistance are found: low level, nontransmissible; and high level, tranmissible. The nontransmissible type of resistance results from a chromosomal mutation which increases the production of a beta-lactamase that hydrolyses cephalosporins relatively rapidly and gives cephalothin r...

A plasmid-encoded beta-lactamase produced from a clinical strain of Providencia stuartii has been purified and characterized. The gene coding for the beta-lactamase was cloned and sequenced. It appears to be a new natural TEM-derived enzyme, named TEM-60. Point mutations (Q39K, L51P, E104K, and R164S) are present with respect to the TEM-1 enzyme; the mutation L51P has never been previously repo...

We surveyed β-lactamase-producing Escherichia coli from farm animals (chickens, pigs, and cattle) and raw retail meat in Shizuoka Prefecture, Japan. In total 305 E. coli isolates, 15 isolates collected from broilers, beef cattle, chicken meat, and pork meat, were found to have β-lactamase genes encoding CTX-M-2, CTX-M-14, CMY-2, SHV-2, and/or TEM-1, whereas 7 possessed mutations in the ampC pro...

Background: Community-acquired infections by multidrug-resistant (MDR), extended-spectrum β-lactamase (ESBL) producing Klebsiella species (Klebsiella spp.) is of major concern worldwide. Antibiotic resistance, production of extended-spectrum β-lactamases (ESBLs), and carbapenemases, as well as the presence of classes 1, 2, and 3 integrons in outpatient isolates of Klebsiella collected from Yazd...

Abstract Background To investigate the trends and correlation between antibacterial consumption carbapenem resistance in Gram-negative bacteria from 2012 to 2019 a tertiary-care teaching hospital southern China. Methods This retrospective study included data hospital-wide inpatients collected January December 2019. Data on were expressed as defined daily doses (DDDs)/1000 patient-days. Antibact...

Abstract Background Routine administration of antibacterials in patients with Covid-19 has been a subject debate, no solid data about the true prevalence respiratory coinfections different geographic areas. The aim current study was to identify admitted hospital and its genetic resistance pattern using multiplex polymerase chain reaction (PCR). Results included 40 patients, 32 males (80%) 8 (20...

Strains of Haemophilus influenzae type b sporadically isolated from clinical specimens are ampicillin resistant due to production of a beta-lactamase. This enzyme which inactivates ampicillin and penicillin G is not produced by ampicillin-susceptible strains. Various characteristics of beta-lactamase production and ampicillin resistance of three H. influenzae type b isolates were investigated. ...

Bacteria that simultaneously produce multiple extended-spectrum beta-lactamases are frequently isolated. We report an Enterobacter cloacae isolate, ES24, producing four different beta-lactamases (AmpC type beta-lactamase, TEM-1, SHV-7, and a novel extended-spectrum beta-lactamase, SHV-30). Direct sequencing of bla(SHV) gene products gave a "double peak" at position 703, suggesting the presence ...

A Klebsiella pneumoniae isolate was identified that had reduced susceptibility to several expanded-spectrum cephalosporins and imipenem. That isolate produced a chromosome-encoded SHV-type beta-lactamase, SHV-38, that had an alanine to valine substitution in position Ambler 146 compared to beta-lactamase SHV-1. The kinetic parameters for purified beta-lactamases SHV-38 and SHV-1 showed that the...