Phenotypic and Genotypic Characterization of Extended-Spectrum ß-Lactamase-Producing Enterobacteriaceae in Asymptomatic Bacteriuria in Pregnancy.

Asymptomatic bacteriuria (ASB) has been consistently observed in pregnancy. However, there is a paucity of data on the prevalence and characteristics of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae in ASB in pregnant women. Therefore, we sought to investigate ESBL-producing and multidrug-resistant Enterobacteriaceae in antenatal women with ASB. Urine samples were collected from 310 asymptomatic pregnant women attending primary antenatal clinics and screened for significant bacteriuria. Isolates of Enterobacteriaceae were phenotypically tested for their ESBL production. ESBL genes (CTX-M, TEM, and SHV genes) were then amplified by polymerase chain reaction (PCR). Multiplex PCRs were used to perform phylogenetic typing of ESBL-producing Escherichia coli isolates and to examine the commonality of sequence type 131 (ST131)-O25b and ST131-O16. A total of 103 (33.2%) pregnant women were positive for significant bacteriuria (80 Enterobacteriaceae). Of these isolates, 32.5% (n = 26) were ESBL producers and had a higher rate of multidrug resistance than non-ESBL producers. Genotypic characterization of ESBL-producing isolates showed that 84.6% had the blaCTX-M gene (blaCTX-M-15 = 77.3%; blaCTX-M-9 = 18.2%). None of the isolates were of the TEM or SHV type. Half of the ESBL-producing E. coli isolates were of the phylogroup B2, and 4 (20%) isolates were of the ST131-O16 clonal subgroup. This study is the first in Egypt to provide evidence for the high prevalence of ESBL-producing Enterobacteriaceae in pregnant women with ASB. It also represents an important step toward genotypic characterization of this resistant form of bacteria, which may be useful for future antimicrobial studies.

High incidence of MBL-mediated imipenem resistance among Pseudomonas aeruginosa from surgical site infections in Egypt.

INTRODUCTION: Surgical wound infection is a serious problem, especially with metallo-beta lactamases (MBLs)- producing gram-negative bacteria as Pseudomonas aeruginosa. The main objective of this work was to evaluate for the first time in Minia- Upper Egypt, the incidence of imipenem-resistant Pseudomonas aeruginosa infection of surgical wounds particularly that mediated by MBL production. METHODOLOGY: P. aeruginosa was isolated from infected wounds by swabs and underwent full microbiological identification and Antibiotic Susceptibility testing. MBL production was tested by E-test and PCR was used for imipenemase (blaIMP) and Verona integron-encoded metallo-beta-lactamase (blaVIM) gene detection. RESULTS: Out of 200 pus samples collected from surgical site infections, P. aeruginosa had the prevalence rate of 35%. Imipenem resistance was found in 28.57% of the isolated Pseudomonas aeruginosa. The prevalence of MBL-producing isolates among Imipenem-resistant P. aeruginosa (IRPA) was 85 % by phenotypic method with 29% of them harboring blaVIM gene. High resistance rates to other classes of antibiotics were reported among the isolates with multi-drug resistance (MDR) detected in 97.3% of the isolates. CONCLUSION: To our knowledge, this is the first report in Minia, Upper Egypt describing the relatively high incidence of IRPA in infected surgical wounds with MBLs involved in the majority of isolates.