Fecal carriage of extended-spectrum and AmpC β-lactamase-producing Enterobacteriaceae in surgical patients before and after antibiotic prophylaxis

Unraveling virulence determinants in extended-spectrum beta-lactamase-producing Escherichia coli from East Africa using whole-genome sequencing

Escherichia coli significantly causes nosocomial infections and rampant spread of antimicrobial resistance (AMR). There is limited data on genomic characterization of extended-spectrum β-lactamase (ESBL)-producing E. coli from African clinical settings. This hospital-based longitudinal study unraveled the genetic resistance elements in ESBL E. coli isolates from Uganda and Tanzania using whole-genome sequencing (WGS). A total of 142 ESBL multi-drug resistant E. coli bacterial isolates from both Tanzania and Uganda were sequenced and out of these, 36/57 (63.1%) and 67/85 (78.8%) originated from Uganda and Tanzania respectively. Mutations in RarD, yaaA and ybgl conferring resistances to chloramphenicol, peroxidase and quinolones were observed from Ugandan and Tanzanian isolates. We reported very high frequencies for blaCTX-M-15 with 11/18(61.1%), and blaCTX-M-27 with 12/23 (52.1%), blaTEM-1B with 13/23 (56.5%) of isolates originating from Uganda and Tanzania respectively all conferring resistance to Beta-lactam-penicillin inhibitors. We observed chloramphenicol resistance-conferring gene mdfA in 21/23 (91.3%) of Tanzanian isolates. Extraintestinal E. coli sequence type (ST) 131 accounted for 5/59 (8.4%) of Tanzanian isolates while enterotoxigenic E. coli ST656 was reported in 9/34 (26.4%) of Ugandan isolates. Virulence factors originating from Shigella dysenteriae Sd197 (gspC, gspD, gspE, gspF, gspG, gspF, gspH, gspI), Yersinia pestis CO92 (irp1, ybtU, ybtX, iucA), Salmonella enterica subsp. enterica serovar Typhimurium str. LT2 (csgF and csgG), and Pseudomonas aeruginosa PAO1 (flhA, fliG, fliM) were identified in these isolates. Overall, this study highlights a concerning prevalence and diversity of AMR-conferring elements shaping the genomic structure of multi-drug resistant E. coli in clinical settings in East Africa. It underscores the urgent need to strengthen infection-prevention controls and advocate for the routine use of WGS in national AMR surveillance and monitoring programs.Availability of WGS analysis pipeline: the rMAP source codes, installation, and implementation manual can free be accessed via https://github.com/GunzIvan28/rMAP .

Carriage of β-lactamase and carbapenemase-producing Enterobacteriaceae in hospitalized patients at debre tabor comprehensive specialized hospital

Background

Antimicrobial resistance has remained global public health threat. Carriage with drug-resistant bacterial pathogens, particularly beta-lactamase and carbapenemase-producing Enterobacteriaceae is among the most concerning. The purpose of this study was to look into the magnitude, antimicrobial resistance patterns, and associated risk factors among hospitalized patients.

Methods

A facility-based cross-sectional study was conducted on 383 hospitalized patients at Debre Tabor Comprehensive Specialized Hospital between September 2022 and May 2023. A pre-tested structured questionnaire was used to collect sociodemographic and clinical data. The data on the etiologic agent was collected using standard bacteriological techniques. Briefly, stool specimens were collected aseptically into sterile, leak-proof stool cups. The stool sample was inoculated onto MacConkey agar and incubated aerobically at 37 °C for 24 h. The species isolation and antimicrobial resistance patterns were then performed adhering to bacteriological procedures. In the analysis, a p-value of <0.05 was considered statistically significant.

Results

There were 383 study participants, and men made up the majority (55.6%). The study participants' mean age was 33 ± 18 years. Three hundred and seventy-seven (88%) of the study's participants had no previous history of antibiotic use. There were 102 (26.6%) and 21 (5.5%) cases of gastrointestinal carriage caused by Enterobacteriaceae that produce beta-lactamase and carbapenemase, respectively. In total, 175 isolates of Enterobacteriaceae were detected. E. coli (n = 89) and K. pneumoniae (n = 51) were the most frequently recovered. In this study, 46 (79.3%) and 8 (13.8%) isolates of E. coli that produce beta-lactamase were resistant to ampicillin and amoxicillin/clavulanic acid, respectively. Furthermore, participants who had previously used antibiotics experienced a two-fold increase in exposure to gastrointestinal tract carriage by carbapenemase-producing Enterobacteriaceae [AOR, 95% CI (2.01, 1.06-2.98), p = 0.001].

Conclusions

The emergence of drug-resistant pathogens is a growing concern. An increase in the prevalence of drug-resistant infections in hospitalized patients is warranting further investigation.

Gastrointestinal Tract Colonization Rate of Extended-Spectrum Beta-Lactamase-Producing Gram-Negative Bacteria and Associated Factors Among Orthopaedic Patients in a Tertiary Hospital in Tanzania: Implications for Infection Prevention

Background

The dual burden of road traffic accidents and antimicrobial resistance in orthopaedic infections is challenging already strained health-care systems. Limited information exists in Tanzania on antimicrobial resistance surveillance to delineate the potential sources of multi-drug-resistant bacteria for specific mitigation strategies among orthopaedic patients.

Methods

A longitudinal study was conducted at Bugando Medical Centre in Mwanza city between January and May 2020. It involved the collection of rectal swabs/stools, hand swabs, and environmental sampling to identify extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacteria. Participants’ data were collected using a structured questionnaire and analysed to determine factors associated with ESBL colonization among index orthopaedic patients and correlates with other ESBL sources using OR (95% CI) and a cut-off p-value of ≤0.05.

Results

We found that 47.2% (125/265) of index patients, 77.8% (14/18) of neighbouring patients, 8.3% (2/24) of health-care workers, 72.2% (13/18) of non-medical caregivers, and 31.4% (27/86) of samples taken from the hospital environment had ESBL producers. Escherichia coli and Klebsiella spp. predominated among participants and Acinetobacter spp. predominated in the environmental samples. Patients with open fractures had increased odds of being colonized with ESBL producers [OR (95% CI): 2.08 (1.16–3.75); p=0.015]. The floor below patients’ beds was commonly contaminated; however, the odds of environmental contamination decreased on the third round of sampling [OR (95% CI: 0.16 (0.04–0.67); p=0.012], apparently as a result of parallel infection prevention and control responsive measures against coronavirus disease 2019 (COVID-19).

Conclusion

We found a high occurrence of ESBL colonization among participants and in the environmentat this tertiary hospital. The importance of routine ESBL surveillance among orthopaedic patients with open fractures on admission and strengthened decontamination of health-care premises is reiterated.

Admission prevalence of colonization with third-generation cephalosporin-resistant Enterobacteriaceae and subsequent infection rates in a German university hospital

Background

Many patients admitted to a hospital are already colonized with multi-drug resistant organisms (MDRO) including third-generation cephalosporin-resistant Enterobacteriaceae (3GCREB). The aim of our study was to determine the prevalence of rectal 3GCREB colonization at admission to a large German university hospital and to estimate infection incidences. In addition, risk factors for 3GCREB colonization were identified.

Materials/Methods

In 2014 and 2015, patients were screened for rectal colonization with 3GCREB and filled out a questionnaire on potential risk factors at admission to a non-intensive care unit (non-ICU). All patients were retrospectively monitored for bacterial infections. Descriptive, univariable and multivariable logistic regression analyses were conducted to identify risk factors for 3GCREB colonization at admission.

Results

Of 4,013 patients included, 10.3% (n = 415) were rectally colonized with 3GCREB at admission. Incidence of nosocomial infections was 3.5 (95% CI 2.0–6.1) per 100 patients rectally colonized with 3GCREB compared to 2.3 (95% CI 1.8–3.0, P = 0.213) per 100 3GCREB negative patients.

Independent risk factors for 3GCREB colonization were prior colonization / infection with MDRO (OR 2.30, 95% CI 1.59–3.32), prior antimicrobial treatment (OR 1.97, 95% CI 1.59–2.45), male sex (OR 1.38, 95% CI 1.12–1.70), prior travelling outside Europe (OR 2.39, 95% CI 1.77–3.22) and places of residence in the Berlin districts Charlottenburg-Wilmersdorf (OR 1.52, 95% CI 1.06–2.18), Friedrichshain-Kreuzberg (OR 2.32, 95% CI 1.44–3.74) and Mitte (OR 1.73, 95% CI 1.26–2.36).

Conclusions

Admission prevalence of rectal colonization with 3GCREB was high, while infection incidence did not significantly differ between patients rectally colonized or not with 3GCREB at hospital admission. In consequence, hospitals should prioritize improvement of standard precautions including hand hygiene to prevent infections among all patients irrespective of their 3GCREB status at hospital admission.

In-Hospital Surgery as a Risk Factor for Onset of AmpC-Producing Escherichia coli Blood Stream Infections

There has been a progressive rise in the incidence of blood stream infections (BSI) caused by multidrug-resistant Gram-negative organisms (MDR GN), which cause increased morbidity and mortality. For this reason, recent studies have focused on risk factors of acquisition of carbapenemase-producing Enterobacteriaceae and extended-spectrum beta-lactamase producers. However, there is limited data on risk factors for BSI caused by AmpC-producing Enterobacteriaceae (AmpC EC), especially in low prevalence settings such as Australia. This study was performed to identify risk factors for acquisition of AmpC E. coli, using a retrospective matched case control design over a 3-year period. Patients with BSI caused by AmpC E. coli were matched with controls (third generation cephalosporin susceptible E. coli) by age and site of infection (n = 21). There was no significant difference in age, sex, clinical outcome, time to onset of BSI, recent antibiotic use (last 3 months), comorbidities (type 2 diabetes mellitus, renal failure) intensive care unit admission, underlying hematological condition, immunosuppressant use, APACHE II score, or any recent urological procedures (within last 3 months) between the two groups. On univariate analysis, the AmpC E. coli group were more likely to have had a surgical procedure in hospital and lived in a residential aged care facility. On multivariate logistic regression analysis, a recent surgical procedure was associated with the onset of AmpC E. coli BSI (Odd's Ratio (OR) 4.78, p = 0.034). We concluded that in a relatively low prevalence setting such as Australia, AmpC E. coli BSI is potentially associated with surgery performed in hospital due to previous antibiotic exposure and longer hospitalization.