First description of Escherichia coli producing CTX-M-15- extended spectrum beta lactamase (ESBL) in out-patients from south eastern Nigeria

Abstract

We studied the presence of extended spectrum beta lactamases (ESBLs) in 44 clinical isolates of Escherichia coli collected from out-patients in two university teaching hospitals in South-Eastern Nigeria. Species identification was performed by standard microbiology methods and re-confirmed by MALDI-TOF technology. Phenotypic characterization of ESBL enzymes was done by double disc synergy test and presence of ESBL genes was determined by specific PCR followed by sequencing. Transfer of plasmid DNA was carried out by transformation using E. coli DH5 as recipient strain. Phenotypic characterization identified all isolates to be ESBL positive. 77% of strains were from urine, 13.6% from vaginal swabs and 9.0% from wound swabs. 63.6% were from female patients, 68% were from outpatients and 95.5% from patients younger than 30 years. All ESBL producers were positive in a PCR for blaCTX-M-1 cluster, in exemplary strains blaCTX-M-15 was found by sequencing. In all strains ISEcp1 was found upstream and ORF477 downstream of blaCTX-M. PCR for blaTEM and blaOXA-1 was positive in 93.1% of strains, whereas blaSHV was not detected, aac(6′)-Ib-cr was found in 97.7% of strains. RAPD analysis revealed seven different clonal groups named A through G with the majority of the strains (65.9%) belonging to clone A. Transfer of an ESBL plasmid with co-resistance to gentamicin, kanamycin, tobramycin, doxycycline and trimethropim-sulfamethoxazole was successful in 19 (43.2%) strains. This study showed a high rate of CTX-M-1 cluster - ESBLs in South-Eastern Nigeria and further confirms the worldwide spread of CTX-M ESBL in clinical isolates.

Distribution of ESBLs among Escherichia coli isolates from outpatients with recurrent UTIs and their antimicrobial resistance

“…These results are consistent with those of other researchers [10,[23][24][25]28]. Also, our results are in accordance with Pitout et al [29] who reported that repeat UTIs were more likely to be caused by CTX-M-producing strains than by non-CTX-Mproducing strains.…”

“…Similar results were reported from Asia [24,30], Africa [23,25], and Europe [31,32]. In addition to their resistance to thirdand fourth-generation cephalosporins and monobactams, a high percentage of the isolates were also resistant to amoxicillin-clavulanic acid, gentamicin, ciprofloxacin, nalidixic acid, trimethoprimsulfamethoxazole, and tetracycline.…”

“…In Iraq, lack of control over antibiotic use and prescription and the extensive use of antibiotics in our community, especially β-lactams, explained these high rates of ESBL production by clinical isolates from Iraqi people. Other researchers [22,23] reported that antibiotic resistance has become a major problem worldwide as a result of the extensive use of antimicrobial agents. In the Middle East area, notable differences regarding ESBL-EC prevalence were apparent.…”

Strain Typing and Molecular Characterization of CTX-M-1 Group ESBL in Clinical Klebsiella pneumoniae Isolated from Children

“…Among the ESBL-producing strains, the prevalence of bla CTX-M-15 reported in different studies in Iran varies from 62.6%, as reported by Feizabadi et al, (23) to 92.8%, as described by Alizadeh et al (25). In several countries, such as Lebanon, India, France, Spain, the UK, Latin America, and the African countries, CTX-M-15 is now one of the most common CTX-M β-lactamases (5).…”

“…These enzymes hydrolyze cefotaxime better than ceftazidime, although CTX-M-15 (belonging to group 1) has been reported to have good activity against ceftazidime (3). Rapid emergence and dissemination of the CTX-M-15 enzyme has been widely reported, and it is currently the most widely distributed ESBL genotype in most parts of the world (4)(5)(6).…”