Prevalence and Characterization of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae in Major Hospitals in Gabon

Study on extended-spectrum beta-lactamases genes and drug resistance in patients with urinary tract infection of enterohemorrhagic Escherichia coli after bladder cancer surgery

To explore of the detection of enterohemorrhagic Escherichia coli with extended-spectrum beta-lactamase (ESBLs) in patients with urinary tract infections (UTIs) after bladder cancer surgery, and analysis of their genotypic distribution and drug resistance. From February 2022 to February 2024, patients who underwent bladder cancer surgery at our hospital were collected. Among them, those who developed UTIs with enterohemorrhagic E coli postoperatively had their urine specimens isolated and cultured, resulting in 87 strains of enterohemorrhagic E coli. Cultures were conducted on the obtained enterohemorrhagic E coli samples, ESBLs production was screened, and drug sensitivity tests were performed to investigate the resistance rate and antibacterial effects. Additionally, genotypic testing was conducted. This study successfully isolated 87 strains of E coli, among which 49 strains (56.32%) were found to produce ESBLs after screening. The resistance rates of these ESBL-producing E coli to cefotaxime and ampicillin were relatively high (93.88% and 97.96%, respectively), while the resistance rate to imipenem was the lowest (2.04%). Genotypic testing revealed that among the 49 strains of ESBL-producing E coli, the detection rate of blaCTX-M-14 was the highest at 53.06%, followed by bla-TEM at 30.61%. The detection rates of bla-SHV (4.08%), bla-OXA (2.04%), blaCTX-M-3 (2.04%), blaCTX-M-15 (2.04%), as well as combinations of several genotypes (blaCTX-M-3 + bla-TEM, blaCTX-M-14 + bla-TEM, blaCTX-M-15 + bla-TEM, all with a detection rate of 2.04%), were relatively low. Strains carrying the bla-TEM genotype exhibited 100% resistance rates to ampicillin and tetracycline. Strains carrying the blaCTX-M-14 genotype showed a 100% resistance rate to ampicillin and a 96.15% resistance rate to cefotaxime. Bladder cancer patients with postoperative complications of E coli urinary tract infection have a detection rate of 56.32% for ESBL-producing E coli. The detected ESBL-producing strains show a high resistance rate to ampicillin and cefotaxime, with the lowest resistance rate observed against imipenem. Genotypic analysis reveals that blaCTX-M-14 and bla-TEM are the main ESBL genes, with blaCTX-M-14 having the highest detection rate.

Whole-Genome Sequencing of Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae Isolated from Human Bloodstream Infections

Klebsiella pneumoniae is a Gram-negative bacterium commonly associated with bloodstream infections (BSIs), which can lead to severe clinical outcomes, especially in immunocompromised individuals or patients with underlying health conditions. The increasing prevalence of K. pneumoniae that produces extended-spectrum β-lactamases (ESBL) poses a significant challenge for treatment and infection control, necessitating a swift diagnostic approach and tailored antimicrobial therapy to improve patient outcomes. A total of 32 K. pneumoniae isolates were recovered from BSIs from December 2021 to August 2022. Whole-genome sequencing (WGS) was performed on the 14 ESBL-producing isolates. All ESBL isolates carried the blaCTX-M-15 gene, together with other β-lactamase-encoding genes (blaTEM-1, blaSHV-28, blaSHV-26, or blaOXA-1). Three of the isolates also carried the blaKPC-3 gene. Resistance genes to quinolones, sulfonamides, tetracycline, aminoglycosides, and chloramphenicol were also detected. We can conclude that the presence of ESBL-producing isolates among K. pneumoniae of BSIs raises concerns, since these enzymes limit the available treatment options, and future research must include studies on alternative therapies for dealing with resistant bacterial infections and developing new approaches to disease treatment.

Prevalence of Multidrug-Resistant CTX-M Extended Spectrum Beta-Lactamase-Producing Escherichia coli From Different Bovine Faeces in China

CTX-M extended spectrum beta-lactamase-producing Escherichia coli cause severe health hazards in livestock breeding. To date, little is known about antibiotic resistance differences among bacterial isolates from yaks, cows, and beef cattle; therefore, the aims of this study were to analyse the prevalence of CTX-M-producing E. coli in yak, beef cattle, and dairy cattle feces from different provinces in China. A total of 790 fecal samples from yaks, beef cattle, and dairy cows were used. Among all the samples, 523 non duplicate E. coli isolates were identified, and 29.6% of samples harbored CTX-M producers. The results showed that these E. coli strains harbored 15 clusters of CTX-M genes: CTX-M-79, CTX-M-55, CTX-M-15, CTX-M-14, CTX-M-28, CTX-M-179, CTX-M-65, CTX-M-24, CTX-M-27, CTX-M-102, CTX-M-105, CTX-M-173, CTX-M-238, CTX-M-196, and CTX-M-10. The dominant resistance genes were CTX-M-15, CTX-M-14, and CTX-M-55. Moreover, the distribution of CTX-M genes was related to geographical region. Based on the above findings, we reasoned that bovines are potential reservoirs of antibiotic resistance, and this problem should be given adequate attention.

Investigating antibiotic resistance in enterococci in Gabonese livestock

Background and Aim:

The emergence of antibiotic resistance is a major problem worldwide. Antibiotics are often used to prevent or treat infections in livestock. This study aimed to investigate antibiotic resistance in enterococci in Gabonese livestock.

Materials and Methods:

We collected 174 animal samples (46 laying hens, 24 swine, 62 cattle, and 42 sheep) from farms in four provinces of Gabon. Bacterial strains belonging to the genus Enterococcus were obtained using selective media and polymerase chain reaction targeting the tuf gene. Antibiotic susceptibility was determined by the disk diffusion method on Mueller-Hinton agar.

Results:

Enterococci were present in 160 of the samples (97%), distributed as follows: laying hens (100%, 41/41), swine (100%, 22/22), small ruminants (88%, 37/42), and cattle (100%, 60/60). Resistance to cephalothin/cephalexin, streptomycin, and rifampicin (RIF) was high, and resistance to vancomycin (VAN), erythromycin, and tetracycline was moderate. A high diversity of resistance was found in Haut-Ogooué and Estuaire provinces. Laying hens and swine showed moderate levels of resistance to ciprofloxacin and penicillin, while sheep and cattle had high levels of resistance to RIF. All species showed a high level of resistance to VAN. We found various patterns of multiple resistances in the isolates, and the multiple resistance indexes ranged from 0.2 to 0.8.

Conclusion:

This study shows that livestock in Gabon can be considered potential reservoirs of resistance.

The Antibiotics Used in Livestock and Their Impact on Resistance in Enterococcus faecium and Enterococcus hirae on Farms in Gabon

The emergence of antibiotic resistance is a major concern around the world. The objective of this study was to investigate the antibiotics used in livestock and their impact on resistance in Enterococcus faecium and Enterococcus hirae on farms in Gabon. A structured questionnaire was used to collect information on the farms. Samples were collected from farms (n = 20) tested for Enterococcus by culture and isolation and were identified using a polymerase chain reaction (PCR) and sequencing. Antibiotic susceptibility was determined by the disc diffusion method on Mueller Hinton agar. The 20 farms included laying hens (6), swine (6), sheep (4) and cattle farms (4). Tetracycline was the most used antibiotic family (91%) and the most used prophylactic method (47%) for the treatment of animals. A total of 555 samples were collected and 515 (93%) Enterococcus spp. isolates of the genus were obtained. The prevalence of E. faecium and E. hirae were 10% and 8%, respectively. The isolates from E. faecium and E. hirae we found were related to clinical and human isolates in the NCBI database. E. faecium and E. hirae isolates showed a high resistance to tetracycline (69% and 65%) and rifampicin (39% and 56%). The tet(M) gene was detected in 65 tetracycline-resistant isolates with a large majority in hens (78% (21/27) and 86% (12/14) in E. faecium and E. hirae, respectively). The consumption of antibiotics favours the emergence of antibiotic resistance in animals in Gabon.

The Evaluation of Eazyplex® SuperBug CRE Assay Usefulness for the Detection of ESBLs and Carbapenemases Genes Directly from Urine Samples and Positive Blood Cultures

Increasing antimicrobial resistance of Gram-negative rods is an important diagnostic, clinical and epidemiological problem of modern medicine. Therefore, it is important to detect multi-drug resistant strains as early on as possible. This study aimed to evaluate Eazyplex^® SuperBug CRE assay usefulness for beta-lactamase gene detection among Gram-negative rods, directly from urine samples and positive blood cultures. The Eazyplex^® SuperBug CRE assay is based on a loop-mediated isothermal amplification of genetic material and allows for the detection of a selection of genes encoding carbapenemases, KPC, NDM, VIM, OXA-48, OXA-181 and extended-spectrum beta-lactamases from the CTX-M-1 and CTX-M-9 groups. A total of 120 clinical specimens were included in the study. The test gave valid results for 58 (96.7%) urine samples and 57 (95.0%) positive blood cultures. ESBL and/or carbapenemase enzymes genes were detected in 56 (93.3%) urine and 55 (91.7%) blood samples, respectively. The Eazyplex^® SuperBug CRE assay can be used for a rapid detection of the genes encoding the most important resistance mechanisms to beta-lactams in Gram-negative rods also without the necessity of bacterial culture.