Evaluation of antimicrobial susceptibility profile of various bacterial pathogens in the health facilities, abattoirs and related environment is important to assess potential risk of dissemination of resistant pathogens to the environment. There is limited information about antimicrobial susceptibility profile of common Enterobacteriaceae in waste water samples from hospitals, abattoirs and the downstream water bodies in Addis Ababa. The present study assessed antimicrobial susceptibility of bacteria belonging to the family Enterobacteriaceae isolated from wastewater samples (WWS) of two hospitals: Tikur Anbessa Specialized Hospital (TASH) and Minilik II hospital, a wastewater treatment plant (WWTP) and an abattoir, and downstream rivers in Addis Ababa. A total of 54 bacterial isolates belonging to 6 species were identified: E.coli (32%), Salmonella 23%), Klebsiella pneumonia (15%), Enterobacter aerogenes (11%), Citrobacter (7%), Klebsiella oxytoca (6%) and Enterobacter cloacae (6%), respectively. Two strains of Citrobacter spp. isolated from TASH wastewater sample (WWS) were resistant to all 12 antimicrobials tested whereas an E. coli isolate from the same source was resistant to 11 antimicrobials. All isolates were resistant to 2 or more antimicrobials tested. Multi-drug resistance (MDR) to several antimicrobials was recorded, particularly in isolates obtained from hospital WWS and it was more common in Citrobacter and E. coli isolates. Extended spectrum betalactamase (ESBL) production was detected in 27.3% of MDR isolates, all of them obtained from hospital effluents whereas none of the isolates were carbapenemase producers. The present study revealed that Enterobacteriaceae in wastewater from hospitals, abattoir and downstream water bodies are resistant to commonly used antimicrobials. Hospital effluents contained more of MDR bacteria, posing significant public health threat through dissemination to the downstream water bodies.

Antimicrobial resistance of Escherichia coli is a growing problem in both developed and developing countries. This study aimed to investigate the phenotypic antimicrobial resistance of E. coli isolates (n = 260) isolated from the stool specimen of patients attending public health facilities in Addis Ababa and Hossana. This study also aimed to characterize phenotypically confirmed extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates (n = 22) using whole-genome sequencing. Resistance to 18 different antimicrobials was assessed using the disc diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The highest resistance rate among the E. coli isolates was found for ampicillin (52.7%), followed by trimethoprim-sulfamethoxazole (29.6%). Of all isolates, 50 (19.2%) were multidrug-resistant and 22 (8.5%) were ESBL producers. ESBL genes were detected in 94.7% of the sequenced E. coli isolates, and multiple β-lactamase genes were detected in 57.9% of the isolates. The predominant ESBL gene identified was bla_CTX-M-15 (78.9%). The bla_TEM-1B gene was detected in combination with other ESBL genes in 57.9% of the isolates, while only one of the sequenced isolates contained the bla_TEM-1B gene alone. The bla_CTX-M-3 gene was detected in three isolates. The genes bla_CTX-M-15 and bla_TEM-1B as well as bla_CTX-M-15 and bla_TEM-169 were confirmed to coexist in 52.6% and 10.5% of the sequenced E. coli isolates, respectively. In addition, bla_OXA-1 was identified together with bla_CTX-M-15 and bla_TEM-1B in one isolate, and in one isolate, bla_TEM-169 together with bla_CTX-M-15 and bla_TEM-1B was found. The results obtained show that measures need to be taken to reduce the spread of drug resistance and ensure the long-term use of available antimicrobials.

Despite the wide availability of poultry farms in Addis Ababa, limited information is available on the status ofSalmonellain poultry eggs from both farms and retail stores, as well as the antimicrobial susceptibility of isolates. This study aimed to investigate the prevalence, associated risk factors, and antimicrobial susceptibility ofSalmonellain raw chicken eggs and stool samples from humans in contact with poultry in Addis Ababa, Ethiopia. A cross-sectional study was conducted from November 2022 to July 2023. A multistage sampling technique was used to collect 392 pooled egg samples (two eggs per sample) and 48 stool samples from humans in contact with poultry, across 55 farms and 44 retail shops. Standard bacteriological methods were employed to isolate and identifySalmonella, and presumptive isolates were confirmed by PCR. The susceptibility of the isolates to 12 antimicrobials was assessed using the Kirby-Bauer disk diffusion method. The overall prevalence ofSalmonellain eggs was 7.1% (28/392), with the highest prevalence observed in egg shells 21.4% (21/196). MostSalmonellaisolates were recovered from eggs sampled at farms 8.2% (16/196). NoSalmonellawas detected in stool samples from humans in contact with poultry. Farms that did not clean dirty eggs, those with poor handwashing practices before handling eggs, or that did not separate cracked eggs were significantly associated withSalmonellapositivity (p<0.05). Among the 28Salmonellaisolates, 53.6% (15/28) and 46.6% (13/28) were resistant to streptomycin and tetracycline, respectively and multidrug resistance to 3 or more antimicrobials was recorded in 8(28.6%) of Salmonella isolates. The presence of antimicrobial-resistantSalmonellain chicken eggs is an indicative of significant public health concern. Raising public awareness about antimicrobial resistantSalmonellaand implementing appropriate food safety measures are essential to reduce the risk of zoonotic salmonellosis.

Background: Urinary tract infections (UTIs) and antibacterial resistance (ABR) are important public health problems, but they are not well-studied among people living with human immunodeficiency virus (PLHIV) globally, especially in low-income countries. Therefore, it is important to regularly measure the extent of UTIs and ABR in the most susceptible populations. This study aimed to investigate the prevalence of UTIs, associated factors, bacterial causal agents, and their antibiotic susceptibility profile among PLHIV in central Ethiopia.Methods: A hospital-based cross-sectional study was conducted to recruit 688 PLHIV by a simple random sampling method. Background information was gathered through interviews, while clinical information was gathered from recent information sheets of patient charts using organized, pretested, and validated study tools. Midstream urine was collected aseptically and transported to the Microbiology Laboratory of Aklilu Lemma Institute of Pathobiology within 4 h of collection, maintaining its cold chain. Standard conventional microbial culture methods and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry were used to identify the bacterial isolates at the species level. Kirby Bauer’s disk diffusion method was used to determine the antibiotic susceptibility profile of the bacterial isolates based on the interpretation guidelines of the Clinical Laboratory Standard Institute. Logistic regression models were used to examine factors associated with the occurrence of UTIs among PLHIV attending selected hospitals in Addis Ababa, and Adama.Results: Out of 688 PLHIVs involved in the current study, 144 (20.9%) were positive for UTIs, whereas the majority were asymptomatic for UTIs. In the multivariable logistic regression analysis, only HIV RNA ≥ 200 copies/ml [AOR = 12.24 (95% CI, 3.24, 46.20), p < 0.01] and being symptomatic for UTIs during the study period [AOR = 11.57 (95% CI, 5.83, 22.97), p < 0.01] were associated with the occurrence of UTIs. The dominant bacterial species isolated were Escherichia coli (E. coli; n = 65; 43%), followed by Enterococcus faecalis (E. faecalis; n = 16; 10.6%) and Klebsiella pneumoniae (K. pneumoniae; n = 11; 7.3%). Over half of the E. coli isolates were resistant to antibiotics such as gentamicin (GM; n = 44; 67.7%), amikacin (AN; n = 46; 70.8%), nalidixic acid (NA; n = 42; 64.6%), ciprofloxacin (CIP; n = 40; 61.5%), and azithromycin (AZM; n = 45; 69.2%). All of the K. pneumoniae isolates (n = 11; 100%), (n = 6; 54.5%), and (n = 7; 63.6%) were resistant to [amoxicillin as well as amoxicillin + clavulanic acid], ceftriaxone, and sulfamethoxazole + trimethoprim, respectively. All the Staphylococcus aureus (S. aureus) isolates were resistant to cefoxitin, which implies methicillin-resistant S. aureus (MRSA).Conclusion: The high prevalence of UTIs and antibiotic resistance revealed in the current study needs public health interventions such as educating the population about preventive measures and the importance of early treatment of UTIs. Our findings also highlight the need to provide UTI screening services for PLHIV, and healthcare providers should adopt antibiotic stewardship programs to promote and ensure their appropriate and judicious use.

The diarrheagenic Escherichia coli (DEC) is the major cause of diarrheal diseases in Africa, including Ethiopia. However, the genetic diversity of E. coli pathotypes found in Ethiopia has not been studied well. This study aimed to characterize potential DEC belonging to enteropathogenic (EPEC), Shiga toxin-producing (STEC), enteroaggregative (EAEC), enterotoxigenic (ETEC), and enteroinvasive (EIEC) E. coli pathotypes from stool specimens of patients attending primary healthcare units (n = 260) in Addis Ababa and Hossana using whole-genome sequencing. Real-time PCR assays were used to identify DEC isolates belonging to EPEC, STEC, EAEC, ETEC, and EIEC pathotypes, which were then subjected to whole-genome sequencing on the Illumina platform. Twenty-four whole-genome nucleotide sequences of DEC strains with good enough quality were analyzed for virulence-associated genes (VAGs), antibiotic resistance genes (ARGs), phylogenetic groups, serogroups, and sequence types. The majority (62.5%) of DEC isolates belonged to the phylogenetic group B1. The identified DEC isolates belonged to 21 different serogroups and 17 different sequence types. All tested DEC isolates carried multiple VAGs and ARGs. The findings highlight the high diversity in the population structure of the studied DEC isolates, which is important for designing targeted interventions to reduce the diarrheal burden in Ethiopia.

The global spread of antimicrobial resistance genes (ARGs) in Escherichia coli is a major public health concern. The aim of this study was to investigate the genomic characteristics of extended-spectrum β-lactamase (ESBL)-producing and third-generation cephalosporin-resistant E. coli from a previously obtained collection of 260 E. coli isolates from fecal samples of patients attending primary healthcare facilities in Addis Ababa and Hossana, Ethiopia. A total of 29 E. coli isolates (19 phenotypically confirmed ESBL-producing and 10 third-generation cephalosporin-resistant isolates) were used. Whole-genome sequencing (NextSeq 2000 system, Illumina) and bioinformatic analysis (using online available tools) were performed to identify ARGs, virulence-associated genes (VAGs), mobile genetic elements (MGEs), serotypes, sequence types (STs), phylogeny and conjugative elements harbored by these isolates. A total of 7 phylogenetic groups, 22 STs, including ST131, and 23 serotypes with different VAGs were identified. A total of 31 different acquired ARGs and 10 chromosomal mutations in quinolone resistance-determining regions (QRDRs) were detected. The isolates harbored diverse types of MGEs, with IncF plasmids being the most prevalent (66.7%). Genetic determinants associated with conjugative transfer were identified in 75.9% of the E. coli isolates studied. In conclusion, the isolates exhibited considerable genetic diversity and showed a high potential for transferability of ARGs and VAGs. Bioinformatic analyses also revealed that the isolates exhibited substantial genetic diversity in phylogenetic groups, sequence types (ST) and serogroups and were harboring a variety of virulence-associated genes (VAGs). Thus, the studied isolates have a high potential for transferability of ARGs and VAGs.