In vivo emergence of a still uncommon resistance to fidaxomicin in the urgent antimicrobial resistance threat Clostridioides difficile.

BACKGROUND: Fidaxomicin is a first-line treatment for Clostridioides difficile infections (CDIs). Fidaxomicin resistance has rarely been reported in this urgent antimicrobial resistance threat as defined by the CDC. OBJECTIVES: To report a case of fidaxomicin-resistant C. difficile isolation in a patient treated by fidaxomicin, characterize the genetic determinant for resistance and the consequences on pathophysiological traits, and review the literature. PATIENT AND METHODS: A 38-year-old male patient with several risk factors for CDI experienced three episodes of hospital-acquired CDI and received fidaxomicin for the first episode. The successive isolates were subjected to phenotypic characterization (antimicrobial susceptibility, growth, sporulation ability and toxin production) and WGS analysis to evaluate clonality and modifications associated with resistance. RESULTS: Resistance to fidaxomicin arose in isolates from the recurrences of CDI (MIC: 16 mg/L). WGS analysis showed a close genetic link between strains suggestive of relapses in this patient. A T3428G mutation in the rpoB gene might be associated with fidaxomicin resistance. The resistance was associated with defects in growth, sporulation and production of toxins. A review of the literature found only three previous fidaxomicin-resistant C. difficile clinical strains. CONCLUSIONS: Although rarely reported, resistance to fidaxomicin may quickly emerge in vivo after a single course of treatment. This observation supports the need for prospective surveillance of the susceptibility of C. difficile to treatment antibiotics. However, the clinical relevance of fidaxomicin resistance still needs to be elucidated, particularly due to its apparent rareness and associated fitness cost.

Epidemiology and microbiological features of anaerobic bacteremia in two French University hospitals.

Bacteremia implicating anaerobic bacteria (BIAB) represents 2-6% of all episodes of bacteremia and is associated with high mortality. In this retrospective study from June 2015 to December 2016, we compared BIAB frequency in two hospital centers in Montpellier (France): Montpellier university hospital (MUH) and a center specialized in cancer (ICM). Among the 2465 microbiologically relevant episodes of bacteremia, we identified 144 (5.8%) in which anaerobic bacteria were implicated. BIAB frequency was higher at ICM than MUH (10.4%, vs. 4.9%, p < 0.01). Poly-microbial bacteremia was more frequent among the BIAB episodes (31.9% vs. 11.0% for aerobic-only bacteremia, p < 0.01). Bacteroides and Clostridium were the most frequently identified genera of anaerobic bacteria (64 and 18 episodes, respectively), with the B. fragilis group (BFG) involved in 68/144 episodes. We could perform antibiotic susceptibility typing in 106 of the 144 anaerobic isolates, including 67 BFG isolates. All isolates but one were susceptible to metronidazole. In the BFG, sporadic resistant or intermediate results were found for amoxicillin-clavulanate (5/67), piperacillin-tazobactam (2/67) and imipenem (1/67). BFG isolates were susceptible also to cefoxitin (90.8%), rifampicin (97.0%) and tigecyclin (91.0%). Multidrug resistance in this group (7 isolates) was mostly due to acquired resistance to moxifloxacin, clindamycin and tigecyclin. This study shows that BIAB frequency can vary among hospitals and services. They should especially be taken into account in centers specialized in cancer treatment. However, the implicated bacteria remain frequently susceptible to the most used antibiotics used against anaerobic bacteria, although resistance does exist.

Spread of NDM-5 and OXA-181 Carbapenemase-Producing Escherichia coli in Chad.

We detected for the first time blaNDM-5 and blaOXA-181 in Escherichia coli isolates from hospitalized patients and healthy volunteers in Chad. These resistance genes were located on IncX3 and IncF plasmids. Despite the large diversity of E. coli clones, the identified resistant intestinal isolates belonged mainly to the same sequence type.

Cervical anaerobic vertebral osteomyelitis following surgical tracheotomy: a case report.

BACKGROUND: We report a rare case of anaerobic vertebral osteomyelitis associated with surgical tracheotomy which has never been reported to the best of our knowledge. CASE PRESENTATION: A healthy 39-year-old man was admitted to intensive care for a severe brain trauma injury where a surgical tracheotomy was performed. He was discharged to a rehabilitation centre after 54 days hospital stay. During rehabilitation, he developed progressive and febrile tetraplegia associated with cervical pain, requiring an intensive care readmission. A polymicrobial anaerobic bloodstream infection was revealed and magnetic resonance imaging diagnosed cervical vertebral osteomyelitis. Both the type of anaerobic micro-organisms found and the timing of the symptoms strongly suggest that the surgical tracheotomy was responsible for this rare case of cervical vertebral osteomyelitis. The patient was successfully treated by a prolonged antimicrobial therapy and by surgical laminectomy. CONCLUSIONS: Tracheotomy may generate anaerobic bacteraemia and related osteomyelitis in the specific setting of severe trauma patients. Clinicians should consider anaerobic vertebral osteomyelitis when they are confronted with a febrile tetraplegia after tracheotomy.

High prevalence and characterization of extended-spectrum ß-lactamase producing Enterobacteriaceae in Chadian hospitals.

BACKGROUND: Extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) represent a major problem in the management of nosocomial infections. However, ESBL-PE are not systematically monitored in African countries. The aim of this study was to determine ESBL-PE prevalence in patients from three hospitals in N'Djamena, the capital city of Chad, and to characterize the genetic origin of the observed resistance. METHODS: From January to March 2017, 313 non-duplicate isolates were recovered from various clinical specimens obtained from 1713 patients in the three main hospitals of N'Djamena. Bacterial species were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Susceptibility to 28 antibiotics was tested using the disk diffusion method on Müller-Hinton agar, and ESBL production was confirmed with the double-disc synergy test. The most prevalent ESBL genes associated with the observed resistance were detected using multiplex PCR followed by double-stranded DNA sequencing. RESULTS: Among the 313 isolates, 197 belonged to the Enterobacteriaceae family. The overall ESBL-PE prevalence was 47.72% (n = 94/197), with a higher rate among inpatients compared with outpatients (54.13% vs. 34.37%). ESBL-PE prevalence was highest in older patients (≥60 years of age). E. coli was the most common ESBL-producer organism (63.8%), followed by K. pneumoniae (21.2%). ESBL-PE were mainly found in urine samples (75%). The CTX-M-1 group was dominant (96.7% of the 94 ESBL-PE isolates, CTX-M-15 enzyme), followed by the CTX-M-9 group (4.1%). 86% of resistant isolates harbored more than one ESBL-encoding gene. ESBL production was also associated with the highest levels of resistance to non-ß-lactam drugs. CONCLUSIONS: The prevalence of ESBL-PE harboring resistant genes encoding ESBLs of the CTX-M-1 group was high (48%) among clinical isolates of three main hospitals in Chad, suggesting an alarming spread of ESBL-PE among patients.

Comparing identification of clinically relevant Prevotella species by VITEK MS and MALDI biotyper.

In this multicenter study, we aimed to evaluate the performance of MALDI Biotyper and VITEK MS, for identification of Prevotella species. Three hundred and fourteen clinical isolates, collected in eight European countries between January 2014 and April 2016, were identified at the collecting sites by MALDI Biotyper (versions 3.0 and 3.1) and then reidentified by VITEK MS (version 3.0) in the central laboratory. 16S rRNA gene sequencing was used as a standard method. According to sequence analysis, the 314 Prevotella strains belonged to 19 species. MALDI Biotyper correctly identified 281 (89.5%) isolates to the species level and 33 (10.5%) only at the genus level. VITEK MS correctly identified 253 (80.6%) isolates at the species level and 276 (87.9%) isolates at the genus level. Thirty-three isolates belonging to P. bergensis, P. conceptionensis, P. corporis, P. histicola, and P. nanciensis, unavailable in the VITEK MS 3.0 database, were resulted in genus level or no identification. Six Prevotella strains, belonged to P. veroralis, P. timonensis, and P. conceptionensis not represented in the MALDI Biotyper system database, were misidentified at the genus level. In conclusion, both VITEK MS and MALDI Biotyper provided reliable and rapid identification. However, the permanent extension of the databases is needed.

Clinical sources and antimicrobial susceptibility of Prevotella timonensis at the university hospital of Montpellier, France.

We describe 84 clinical isolates of Prevotella timonensis recovered between January 2007 and November 2016 at the University Hospital of Montpellier. They were recovered from a variety of clinical samples, mostly of genital and wound origins. All isolates were isolated from a mixed aerobic and anaerobic microbiota. Antimicrobial susceptibility testing of 50 isolates showed 56% of beta-lactamase production and 40% of resistance to clindamycin. One strain was resistant to metronidazole.

Performance of mass spectrometric identification of clinical Prevotella species using the VITEK MS system: A prospective multi-center study.

Prevotella species, members of the human microbiota, can cause opportunistic infections. Rapid and accurate identification of Prevotella isolates plays a critical role in successful treatment, especially since the antibiotic susceptibility profile differs between species. Studies, mostly carried out using the Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) Biotyper system, showed that MALDI-TOF MS is an accurate, rapid and satisfactory method for the identification of clinically important anaerobes. In this multi-center study, we assessed the performance of the MALDI-TOF MS VITEK MS system for the identification of clinical Prevotella isolates. A total of 508 Prevotella isolates, representing 19 different species, collected from 11 European countries, Kuwait and Turkey between January 2014 and April 2016, were identified using VITEK MS (v3.0). The reliability of the identification was assessed by 16S rRNA gene sequencing. Using VITEK MS, 422 (83.1%) of the 508 isolates were identified on the species level, 459 (90.4%) on the genus level. A total of 49 (9.6%) isolates were not identified correctly. 16S rRNA gene sequencing results showed that this was partly due to the fact that several species were not represented in the database. However, some species that were represented in the database were also not identified. Five Prevotella strains were misidentified at the genus level, 2 of these strains belonged to a species not represented in the database. In general, the VITEK MS offers a reliable and rapid identification of Prevotella species, however the databases needs to be expanded.

A multicenter survey of antimicrobial susceptibility of Prevotella species as determined by Etest methodology.

Knowledge about the antimicrobial susceptibility patterns of different Prevotella species is limited. The aim of this study was to determine the current antimicrobial susceptibility of clinical isolates of Prevotella species from different parts of Europe, Kuwait and Turkey. Activity of 12 antimicrobials against 508 Prevotella isolates, representing 19 species, were tested according to Etest methodology. EUCAST, CLSI and FDA guidelines were used for susceptibility interpretations. All Prevotella species were susceptible to piperacillin/tazobactam, imipenem, meropenem, tigecycline and metronidazole. Ampicillin/sulbactam and cefoxitin also showed good activity. Ampicillin, clindamycin, tetracycline and moxifloxacin were less active; 51.2%, 33.7%, 36.8% and 18.3% of isolates were non-susceptible, respectively. A total of 49 (9.6%) isolates were resistant to three or more antimicrobials. Prevotella bivia was the most prevalent species (n = 118) and accounted for most of the multidrug-resistant isolates. In conclusion, the level of non-susceptibility to antimicrobials, which may be used for treatment of infections involving Prevotella species, are a cause of concern. This data emphasizes the need for species level identification of clinical Prevotella isolates and periodic monitoring of their susceptibility to guide empirical treatment.

Repeated Piperacillin-Tazobactam Plasma Concentration Measurements in Severely Obese Versus Nonobese Critically Ill Septic Patients and the Risk of Under- and Overdosing.

OBJECTIVE: Obesity and critical illness modify pharmacokinetics of antibiotics, but piperacillin-tazobactam continuous IV infusion pharmacokinetics has been poorly studied in obese critically ill patients. We aimed to compare pharmacokinetics of piperacillin in severely obese and nonobese patients with severe sepsis or septic shock. We hypothesized that plasma concentration variability would expose the critically ill to both piperacillin under and overdosing. METHODS: Prospective comparative study. Consecutive critically ill severely obese (body mass index, > 35 kg/m) and nonobese patients (body mass index, < 30 kg/m) were treated with 16 g/2 g/24 hr continuous piperacillin-tazobactam infusion. Piperacillin plasma concentration was measured every 12 hours over a 7-day period by high-pressure liquid chromatography. Unbound piperacillin plasma concentration and fractional time of plasma concentration spent over 64 mg/L (4-fold the minimal inhibitory concentration for Pseudomonas aeruginosa) were compared between the two groups. We performed 5,000 Monte Carlo simulations for various dosing regimens and minimal inhibitory concentration and calculated the probability to spend 100% of the time over 64 mg/L. RESULTS: We enrolled 11 severely obese and 12 nonobese patients and obtained 294 blood samples. We did not observe a statistically significant difference in piperacillin plasma concentrations over time between groups. The fractional time over 64 mg/L was 64% (43-82%) and 93% (85-100%) in obese and nonobese patients, respectively, p = 0.027 with intra- and intergroup variability. Five nonobese and two obese patients experienced potentially toxic piperacillin plasma concentrations. When 64 mg/L was targeted, Monte Carlo simulations showed that 12 g/1.5 g/24 hr was inadequate in both groups and 16 g/2 g/24 hr was adequate only in nonobese patients. CONCLUSION: Using a conventional dosing of 16 g/2 g/24 hr continuous infusion, obese patients were more likely than nonobese patients to experience piperacillin underdosing when facing high minimal inhibitory concentration pathogens. The present study suggests that piperacillin drug monitoring might be necessary in the sickest patients who are at the highest risk of unpredictable plasma concentration exposing them to overdose, toxicity, underdosing, and treatment failure.

High Prevalence of SXT/R391-Related Integrative and Conjugative Elements Carrying blaCMY-2 in Proteus mirabilis Isolates from Gulls in the South of France.

The genetic structures involved in the dissemination of blaCMY-2 carried by Proteus mirabilis isolates recovered from different gull species in the South of France were characterized and compared to clinical isolates. blaCMY-2 was identified in P. mirabilis isolates from 27/93 yellow-legged gulls and from 37/65 slender-billed gulls. It was carried by a conjugative SXT/R391-like integrative and conjugative element (ICE) in all avian strains and in 3/7 human strains. Two clinical isolates had the same genetic background as six avian isolates.

High prevalence of extended-spectrum ß-lactamase producing enterobacteriaceae among clinical isolates in Burkina Faso.

BACKGROUND: Nothing is known about the epidemiology and resistance mechanisms of extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) in Burkina Faso. The objective of this study was to determine ESBL-PE prevalence and to characterize ESBL genes in Burkina Faso. METHODS: During 2 months (June-July 2014), 1602 clinical samples were sent for bacteriologic investigations to the microbiology laboratories of the tree main hospitals of Burkina Faso. Isolates were identified by mass spectrometry using a matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) BioTyper. Antibiotic susceptibility was tested using the disk diffusion method on Müller-Hinton agar. The different ESBL genes in potential ESBL-producing isolates were detected by PCR and double stranded DNA sequencing. Escherichia coli phylogenetic groups were determined using a PCR-based method. RESULTS: ESBL-PE frequency was 58 % (179 strains among the 308 Enterobacteriaceae isolates identified in the collected samples; 45 % in outpatients and 70 % in hospitalized patients). The CTX-M-1 group was dominant (94 %, CTX-M-15 enzyme), followed by the CTX-M-9 group (4 %). ESBL producers were more often found in E. coli (67.5 %) and Klebsiella pneumoniae (26 %) isolates. E. coli isolates (n = 202; 60 % of all Enterobacteriaceae samples) were distributed in eight phylogenetic groups (A = 49, B1 = 15, B2 = 43, C = 22, Clade I = 7, D = 37, F = 13 and 16 unknown); 22 strains belonged to the sequence type ST131. No association between a specific strain and ESBL production was detected. CONCLUSIONS: This report shows the alarming spread of ESBL genes in Burkina Faso. Public health efforts should focus on education (population and healthcare professionals), surveillance and promotion of correct and restricted antibiotic use to limit their dissemination.

Persisting transmission of carbapenemase-producing Klebsiella pneumoniae due to an environmental reservoir in a university hospital, France, 2012 to 2014.

In France, the proportion of episodes of carbapenemase-producing Enterobacteriaceae (CPE) with no recent stay or hospitalisation abroad is increasing. In this study, we investigate epidemiological links between apparently unrelated cases of OXA-48-producing Klebsiella pneumoniae (Kp OXA-48) colonisation or infection. We genotyped detected organisms by repetitive sequence-based PCR, and used a dynamic registry of cases and contacts to cross-reference patients' hospital stays. Between 1 November 2012 and 28 February 2014, 23 Kp OXA-48 cases were detected in a university hospital in Montpellier, of which 15 were involved in three outbreaks: outbreaks I and II occurred in November 2012 and outbreak III in October 2013. Molecular comparison of bacterial strains revealed clonal identity between cases involved in outbreaks II and III and four single cases. Cross-referencing of hospital stays revealed that these single cases and the index case of outbreak III had occupied the same room. Active case search among former occupants of that room found an additional Kp OXA-48 carrier. A clonal strain was isolated from the sink of that room. The epidemiological link between the contaminated room and outbreak II remained undetected. This study is a reminder that environmental reservoirs should be considered as a source of CPE transmission.

Non-O1/Non-O139 Vibrio cholerae Avian Isolate from France Cocarrying the bla(VIM-1) and bla(VIM-4) Genes.

We describe here a non-O1/non-O139 Vibrio cholerae isolate producing both VIM-1 and VIM-4 carbapenemases. It was isolated from a yellow-legged gull in southern France. The blaVIM genes were part of a class 1 integron structure located in an IncA/C plasmid. This study emphasizes the presence of carbapenemase genes in wildlife microbiota.

Rarimicrobium hominis gen. nov., sp. nov., representing the fifth genus in the phylum Synergistetes that includes human clinical isolates.

Five human clinical isolates of an unknown, strictly anaerobic, slow-growing, Gram-stain-negative, rod-shaped micro-organism were subjected to a polyphasic taxonomic study. Comparative 16S rRNA gene sequence-based phylogeny showed that the isolates grouped in a clade that included members of the genera Pyramidobacter, Jonquetella, and Dethiosulfovibrio; the type strain of Pyramidobacter piscolens was the closest relative with 91.5-91.7 % 16S rRNA gene sequence similarity. The novel strains were mainly asaccharolytic and unreactive in most conventional biochemical tests. Major metabolic end products in trypticase/glucose/yeast extract broth were acetic acid and propionic acid and the major cellular fatty acids were C13 : 0 and C16 : 0, each of which could be used to differentiate the strains from P. piscolens. The DNA G+C content based on whole genome sequencing for the reference strain 22-5-S 12D6FAA was 57 mol%. Based on these data, a new genus, Rarimicrobium gen. nov., is proposed with one novel species, Rarimicrobium hominis sp. nov., named after the exclusive and rare finding of the taxon in human samples. Rarimicrobium is the fifth genus of the 14 currently characterized in the phylum Synergistetes and the third one in subdivision B that includes human isolates. The type strain of Rarimicrobium hominis is ADV70T ( = LMG 28163T = CCUG 65426T).

Veillonella seminalis sp. nov., a novel anaerobic Gram-stain-negative coccus from human clinical samples, and emended description of the genus Veillonella.

Ten isolates of unknown, Gram-stain-negative, anaerobic cocci were recovered from human clinical samples, mainly from semen. On the basis of their phenotypic features, including morphology, main metabolic end products, gas production, nitrate reduction and decarboxylation of succinate, the strains were identified as members of the genus Veillonella. Multi-locus sequence analysis and corresponding phylogenies were based on 16S rRNA, dnaK and rpoB genes, and on the newly proposed gltA gene. The strains shared high levels of genetic sequence similarity and were related most closely to Veillonella ratti. The strains could not be differentiated from V. ratti on the basis of 16S rRNA gene sequence analysis while gltA, rpoB and dnaK gene sequences showed 85.1, 93.5 and 90.2% similarity with those of the type strain of V. ratti, respectively. Phylogenetic analyses revealed that the isolates formed a robust clade in the V. ratti-Veillonella criceti-Veillonella magna subgroup of the genus Veillonella. As observed for V. criceti, the isolates were able to ferment fructose. In contrast to other members of the genus Veillonella, the 10 strains were not able to metabolize lactate. Cellular fatty acid composition was consistent with that of other species of the genus Veillonella. From these data, the 10 isolates are considered to belong to a novel species in the genus Veillonella, for which the name Veillonella seminalis sp. nov. is proposed. The type strain is ADV 4313.2(T) ( = CIP 107810(T) = LMG 28162(T)). Veillonella strain ACS-216-V-Col6b subjected to whole genome sequencing as part as the Human Microbiome Project is another representative of V. seminalis sp. nov. An emended description of the genus Veillonella is also proposed.

Sacroiliitis secondary to catheter-related bacteremia due to Mycobacterium abscessus (sensu stricto).

We describe a case of sacroiliitis secondary to catheter-related bacteremia due to Mycobacterium abscessus (sensu stricto). This case confirms that MultiLocus sequence typing and variable-number tandem-repeat methods are very robust techniques to identify the pathogen species and to validate molecular epidemiological links among complex M. abscessus isolates.

Procalcitonin biomarker kinetics fails to predict treatment response in perioperative abdominal infection with septic shock.

INTRODUCTION: Procalcitonin (PCT) biomarker is suggested to tailor antibiotic therapy in the medical intensive care unit (ICU) but studies in perioperative medicine are scarce. The aim of this study was to determine whether PCT reported thresholds are associated with the initial treatment response in perioperative septic shock secondary to intra-abdominal infection. METHODS: This single ICU, observational study included patients with perioperative septic shocks secondary to intra-abdominal infection. Demographics, PCT at days 0, 1, 3, 5, treatment response and outcome were collected. Treatment failure included death related to the initial infection, second source control treatment or a new onset intra-abdominal infection. The primary endpoint was to assess whether PCT thresholds (0.5 ng/ml or a drop from the peak of at least 80%) predict the initial treatment response. RESULTS: We included 101 consecutive cases. Initial treatment failed in 36 patients with a subsequent mortality of 75%. Upon admission, PCT was doubled when treatment ultimately failed (21.7 ng/ml ± 38.7 vs. 41.7 ng/ml ± 75.7; P = 0.04). Although 95% of the patients in whom PCT dropped down below 0.5 ng/ml responded to treatment, 50% of the patients in whom PCT remained above 0.5 ng/ml also responded successfully to treatment. Moreover, despite a PCT drop of at least 80%, 40% of patients had treatment failure. CONCLUSIONS: In perioperative intra-abdominal infections with shock, PCT decrease to 0.5 ng/ml lacked sensitivity to predict treatment response and its decrease of at least 80% from its peak failed to accurately predict treatment response. Studies in perioperative severe infections are needed before using PCT to tailor antibiotic use in this population.

Prevalence and Phenotypic and Molecular Characterization of Carbapenemase-Producing Gram-Negative Bacteria in Gabon.

Data collection and monitoring of carbapenemase-producing (CP) Gram-negative bacteria (GNB) are often limited. This study determined CP-GNB prevalence in Gabon and the genetic origins of the resistance genes. From January 2016 to March 2018, 869 clinically significant GNB isolates from inpatients and outpatients, and 19 fecal samples (inpatients) were analyzed in the main hospitals of Gabon. Fecal samples were screened using ChromID® CARBA SMART selective chromogenic medium biplates. Species were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Antibiotic susceptibility was tested using the disk diffusion method on Müller-Hinton agar, and resistance genes were assessed by multiplex polymerase chain reaction and sequencing. Overall, 1.61% of clinical isolates (14 of 869) and 5.26% of fecal samples (1 of 19) were CP-GNB. The CP-GNB rate was higher among inpatients (2.98%) than outpatients (0.33%), in intensive care units (28.57%, 4 of 14), and in urine samples (35.71%, 5 of 14). The most common CP-GNB were Klebsiella pneumoniae (53.33%) and Acinetobacter baumannii (26.67%). blaOXA-48 was the predominant carbapenemase-encoding gene (40%), followed by blaNDM-5 (33.33%). The A. baumannii multilocus sequence types ST2 and ST78, Enterobacter cloacae ST78, Escherichia coli ST2, and K. pneumonia ST48 and ST147 were found. These data indicate that CP bacteria are present in clinical and carriage samples. Preventive measures are needed to avoid the spread of resistance genes.

Genomic epidemiology of carbapenemase-producing Gram-negative bacteria at the human-animal-environment interface in Djibouti city, Djibouti.

The emergence of carbapenem resistance is a major public health threat in sub-Saharan Africa but remains poorly understood, particularly at the human-animal-environment interface. This study provides the first One Health-based study on the epidemiology of Carbapenemase-Producing Gram-Negative Bacteria (CP-GNB) in Djibouti City, Djibouti, East Africa. In total, 800 community urine samples and 500 hospital specimens from humans, 270 livestock fecal samples, 60 fish samples, and 20 water samples were collected and tested for carbapenem resistance. The overall estimated CP-GNB prevalence was 1.9 % (32/1650 samples) and specifically concerned 0.3 % of community urine samples, 2.8 % of clinical specimens, 2.6 % of livestock fecal samples, 11.7 % of fish samples, and 10 % of water samples. The 32 CP-GNB included 19 Escherichia coli, seven Acinetobacter baumannii, five Klebsiella pneumoniae, and one Proteus mirabilis isolate. Short-read (Illumina) and long-read (Nanopore) genome sequencing revealed that carbapenem resistance was mainly associated with chromosomal carriage of blaNDM-1, blaOXA-23, blaOXA-48, blaOXA-66, and blaOXA-69 in A. baumannii, and with plasmid carriage in Enterobacterales (blaNDM-1 and blaOXA-181 in E. coli, blaNDM-1, blaNDM-5 and blaOXA-48 in K. pneumoniae, and blaNDM-1 in P. mirabilis). Moreover, 17/32 CP-GNB isolates belonged to three epidemic clones: (1) A. baumannii sequence type (ST) 1697,2535 that showed a distribution pattern consistent with intra- and inter-hospital dissemination; (2) E. coli ST10 that circulated at the human-animal-environment interface; and (3) K. pneumoniae ST147 that circulated at the human-environment interface. Horizontal exchanges probably contributed to carbapenem resistance dissemination in the city, especially the blaOXA-181-carrying ColKP3-IncX3 hybrid plasmid that was found in E. coli isolates belonging to different STs. Our study highlights that despite a relatively low CP-GNB prevalence in Djibouti City, plasmids harboring carbapenem resistance circulate in humans, animals and environment. Our findings stress the need to implement preventive and control measures for reducing the circulation of this potentially emerging public health threat.