In spring 2022, an increase in metallo-β-lactamase-producing Pseudomonas aeruginosa (MBL-Pa) infections was detected in a hospital in Upper Austria. To identify the source of infection and to stop further transmissions, an epidemiological outbreak investigation including whole-genome sequencing (WGS)-based typing was conducted. The final case definition included cases admitted to the hospital between 2020 and 2023 with an MBL-Pa in one of the three genomic clusters identified. In addition, the investigation was extended to include historical cases from 2017. Core genome multilocus sequence typing was performed to assess the genetic relatedness between the isolates. Fifty-four clinical P. aeruginosa isolates and eight P. aeruginosa isolates from the hospital environment were obtained. All but nine isolates grouped into one of three genomic clusters (ST235/blaVIM-1, ST111/blaVIM-2, or ST621/blaIMP-13), which were considered to be distinct, prolonged outbreaks involving 47 out of 52 cases. The most likely source of infection for cluster 1 (ST111/blaVIM-2) and cluster 2 (ST235/blaVIM-1) was sinks in the intensive care unit (ICU) washroom. Cluster 3 clone (ST621/blaIMP-13) could have originated in the urology ward in 2020 and then spread to the ICU years later. However, the nosocomial origin of this clone could not be proven. In March 2023, following the implementation of control measures (gowning, patient isolation, screening, and daily disinfection), no further MLB-Pa was detected, and the outbreaks were considered to be over. As ICUs play an important role in the transmission of P. aeruginosa, emphasis should be placed on genomic surveillance, infection prevention, and control in such wards. IMPORTANCE:The significance of our work lies in the successful resolution of three prolonged outbreaks of MBL-Pa infections in a hospital in Upper Austria. Through a comprehensive epidemiological investigation coupled with WGS-based typing of P. aeruginosa isolates, the study identified three distinct genomic clusters responsible for prolonged outbreaks involving 47 cases. The investigation pinpointed sinks in the ICU washroom as the likely source of infection for two of the clusters. The study demonstrates the effectiveness of control measures such as hand hygiene, gowning, patient isolation, screening, and disinfection in stopping further transmission and bringing the outbreaks to a close. This underscores the critical role of genomic surveillance and control measures, particularly in high-risk settings like ICUs, in reducing nosocomial transmission of MBL-Pa infections.

The objective of this study was to characterize Cronobacter spp. and related organisms isolated from powder dairy products intended for consumption by adults and older adults using whole-genome sequencing (WGS), and to identify genes and traits that encode antibiotic resistance and virulence. Virulence (VGs) and antibiotic resistance genes (ARGs) were detected with the Comprehensive Antibiotic Resistance Database (CARD) platform, ResFinder, and MOB-suite tools. Susceptibility testing was performed using disk diffusion. Five presumptive strains of Cronobacter spp. were identified by MALDI–TOF MS and ribosomal MLST. Three C. sakazakii strains were of the clinical pathovar ST1, one was ST31, and the remaining isolate was C. malonaticus ST60. In addition, Franconibacter helveticus ST345 was identified. The C. sakazakii ST1 strains were further distinguished using core genome MLST based on 2831 loci. Moreover, 100% of the strains were resistant to cefalotin, 75% to ampicillin, and 50% to amikacin. The C. sakazakii ST1 strains were multiresistant (MDR) to four antibiotics. Additionally, all the strains adhered to the N1E-115 cell line, and two invaded it. Eighteen ARGs mainly involved in antibiotic target alteration and antibiotic efflux were detected. Thirty VGs were detected and clustered as flagellar proteins, outer membrane proteins, chemotaxis, hemolysins, and genes involved in metabolism and stress. The pESA3, pSP291-1, and pCMA1 plasmids were detected, and the prevalent mobile genetic elements (MGEs) were ISEsa1, ISEc52, and IS26. The isolates of C. sakazakii and C. malonaticus exhibited multiresistance to antibiotics, harbored genes encoding various antibiotic resistance proteins, and various virulence factors. Consequently, these contaminated powdered dairy products pose a risk to the health of hypersensitive adults.

The emergence of antibiotic resistance in food producing animals is of major public health significance arising from the risk of these bacteria entering the food chain. In this study, the genetic characteristics of antibiotic resistant Escherichia coli and Klebsiella spp. isolates from humans and poultry in Edo state, Nigeria were investigated. In April 2017, 45 Klebsiella spp. and 46 Escherichia coli isolates were obtained from urine, clinical wounds, nasal and chicken fecal samples. Isolates were recovered and identified as previously described. Species identification was achieved by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and ribosomal multilocus sequence typing. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer method for 12 antibiotics. Double disc synergy test was used to screen for ESBL production. Whole genome sequencing was performed for strain characterization of the isolates. Thirteen Klebsiella spp. isolates yielded positive results by the ESBL phenotypic test and harbored ESBL genes. Out of the 46 E. coli isolates, 21 human and 13 poultry isolates were resistant to at least one of the tested antibiotics. Four human E. coli isolates harbored ESBL genes and revealed positive results when applying ESBL double disc synergy tests. ESBL genes in the Klebsiella spp. and E. coli isolates include bla CTX-M-15 and bla SHV-28 . Whole genome based cgMLST of the Klebsiella spp. and E. coli isolates revealed a close relatedness among the isolates. An integrated “One Health” surveillance system is required to monitor transmission of antimicrobial resistance in Nigeria.

There is a link between antibiotic resistance in humans, livestock and the environment. This study was carried out to characterize antibiotic resistant bovine and environmental Enterobacteriaceae isolates from Edo state, Nigeria. A total of 109 consecutive isolates of Enterobacteriaceae were isolated from March–May 2015 from 150 fecal samples of healthy bovine animals from three farms at slaughter in Edo state Nigeria. Similarly, 43 Enterobacteriaceae isolates were also obtained from a total of 100 environmental samples from different sources. Isolates were recovered and identified from samples using standard microbiological techniques. Recovered isolates were pre-identified by the Microbact Gram-Negative identification system and confirmed with Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and ribosomal multilocus sequence typing (rMLST). Antibiotic susceptibility testing was carried out by Kirby-Bauer method for 14 antibiotics. Whole genome sequencing (WGS) was carried out for isolate characterization and identification of resistance determinants. Out of 109 animal and 43 environmental Enterobacteriaceae isolates, 18 (17%) and 8 (19%) isolates based on selection criteria showed antibiotic resistance and were further investigated by whole genome sequencing (WGS). Resistance genes were detected in all (100%) of the resistant bovine and environmental Enterobacteriaceae isolates. The resistance determinants included β-lactamase genes, aminoglycoside modifying enzymes, qnr genes, sulfonamide, tetracycline and trimethoprim resistance genes, respectively. Out of the 18 and 8 resistant animal and environmental isolates 3 (17%) and 2 (25%) were multidrug resistant (MDR) and had resistance determinants which included efflux genes, regulatory systems modulating antibiotic efflux and antibiotic target alteration genes. Our study shows the dissemination of antibiotic resistance especially MDR strains among Nigerian bovine and environmental Enterobacteriaceae isolates. The presence of these resistant strains in animals and the environment constitute a serious health concern indicated by the difficult treatment options of the infections caused by these organisms. To the best of our knowledge we report the first detailed genomic characterization of antibiotic resistance in bovine and environmental Enterobacteriaceae isolates for Nigeria.

We report the draft genomes of two Listeria monocytogenes strains that were isolated from the invasive alien snail species Arion vulgaris in Austria in 2019.

Extraintestinal Escherichia coli sequence type 1193 (ST1193) is an important source of fluoroquinolone resistance, which has emerged in recent years. We report the first draft genome sequence and annotation of a multidrug-resistant E. coli ST1193 strain obtained from a wastewater treatment plant in Austria.

The Klebsiella pneumoniae complex comprises several closely related entities, which are ubiquitous in the natural environment, including in plants, animals, and humans. K. pneumoniae is the major species within this complex. K. pneumoniae strains are opportunistic pathogens and a common cause of healthcare-associated infections. K. pneumoniae can colonize the human gastrointestinal tract, which may become a reservoir for infection. The aim of this study was to investigate the fecal K. pneumoniae carriage in six healthy individuals during a 1 year period. Stool samples were obtained once a week. Using direct and pre-enriched cultures streaked on ampicillin-supplemented agar plates, up to eight individual colonies per positive sample were selected for further characterization. Whole genome sequencing (WGS) was performed for strain characterization. Sequence type (ST), core genome complex type (CT), K and O serotypes, virulence traits, antibiotic resistance profiles, and plasmids were extracted from WGS data. In total, 80 K. pneumoniae isolates were obtained from 48 positive cultures of 278 stool samples from five of the six test subjects. The samples of the five colonized volunteers yielded at most two, three, four (two persons), and five different strains, respectively. These 80 K. pneumoniae isolates belonged to 60 STs, including nine new STs; they were of 70 CTs, yielded 48 K serotypes, 11 O serotypes, and 39 wzc and 51 wzi alleles. Four of the five subjects harbored serotypes K20 and K47, as well as STs ST37, ST101, ST1265, and ST20, which had previously been linked to high-risk K. pneumoniae clones. In total, 25 genes conferring antibiotic resistance and 42 virulence genes were detected among all 80 isolates. Plasmids of 15 different types were found among 65 of the isolates. Fecal carriage of individual strains was of short duration: 70 strains were found on a single sampling day only, and 5 strains were isolated in samples collected over two consecutive weeks. Two of the five colonized individuals-working colleagues having meals together-shared identical K. pneumoniae types four times during the study period. Our findings point toward the potential role of food as a reservoir for K. pneumoniae in humans.

Extended Spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are of major concern as they are implicated in multidrug resistant nosocomial infections. They are listed on a recently published global priority list of antibiotic-resistant bacteria by the World Health Organization which raises concern in both healthcare and community settings. This study aimed at determining the frequency of ESBL genes in multidrug resistant human clinical Enterobacteriaceae isolates from Edo state Nigeria and to characterize the resistance mechanisms using whole genome sequencing. A total of 217 consecutive clinical isolates of Enterobacteriaceae, selection based on inclusion criteria, were collected from March-May 2015 from three medical microbiology laboratories of hospitals in Edo state Nigeria. All isolates were analyzed using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Antibiotic susceptibility testing was performed by Kirby-Bauer method and minimum inhibitory concentration (MIC) determination by E-test method. Double disc synergy test was used to screen for the production of ESBL. Whole genome sequencing (WGS) was performed for isolate characterization and identification of resistance determinants. Out of 217 consecutive clinical Enterobacteriaceae isolates, 148 (68.2%) were multi-drug resistant. Of these multi-drug resistant isolates, 60 (40.5%) were positive for the ESBL phenotypic test and carried ESBL genes. CTX-M-15 was the predominant ESBL found, among 93.3% (n = 56/60). Thirty-two plasmid incompatibility groups and 28 known and two new sequence types were identified among the ESBL isolates. The high occurrence of CTX-M-15 with associated resistant determinants in multidrug resistant Enterobacteriaceae harboring different plasmid incompatibility groups and sequence types calls for the need of continuous monitoring of this resistance threat to reduce its public health impact. To our knowledge, this study presents the first genomic characterization of ESBL production mediated by blaCTX-M-15 in human clinical isolates of Enterobacter hormaechei, Citrobacter werkmanii and Atlantibacter hermannii from Nigeria.

The aim of the present study was to investigate the diversity of methicillin-resistant Staphylococcus aureus (MRSA) that originated from Austrian companion animals during the last five-year period. A total of 90 non-repetitive MRSA isolates were obtained during diagnostic activities from autumn 2013 to autumn 2018. They originated from horses (n = 62), cats (n = 13), dogs (n = 10), rabbits (n = 2), a domestic canary, a zoo-kept hammer-headed bat (Hypsignathus monstrosus) and a semi-captive northern bald ibis (Geronticus eremita). Antimicrobial susceptibility testing was performed. All isolates were mecA-positive and mecC-negative. The isolates were genotyped by SCCmec, spa and dru typing, Multiple-Locus Variable number of tandem repeat Analyses (MLVA), S. aureus DNA microarray, and whole-genome sequencing (WGS). Eight sequence types (STs ST398, ST5275 (new ST), ST225, ST8, ST22, ST152, ST1, and ST45), three SCCmec types (II, IV, and V), sixteen spa types (t003, t008, 1011, t015, t032, t034, t1381, t1928, t1985, t223, t334, t355, t430, t6447, t6867, and t7105), fourteen dru types (dt10a, dt10az, dt10q, dt10r, dt11a, dt5e, dt6j, dt9a, dt9ak, dt9g, and four new types dt8as, dt7ak, dt4j, dt14n), and thirty-five MLVA types were detected. WGS-based core genome MLST (cgMLST) displayed five main clusters. Compared to the time period 2004-2013, the results of the present study show not only a higher diversity among the MRSA isolates within the population of Austrian companion animals, but also the introduction of new clones. Although ST398 isolates remained predominant, mainly due to high presence of this lineage among horses, increasing isolation rates of human-associated MRSA clones were observed in cats and dogs.

Purpose: The aim of the present study was to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and ESBL-producing Escherichia coli (ESBL-EC) on Austrian dairy farms, and to compare this to the level of antimicrobial use (AMU) on these farms. Methods & Materials: Farms included were participating in a larger observational study of AMU on 250 farms, quantified by Defined Daily Doses for veterinary medicine (DDDvet). Farmers were recruited using convenience sampling. Here, 50 farms (25 of the highest antimicrobial users and 25 of the lowest users) located in the Austrian federal state of Styria were included in an additional analysis of antimicrobial resistance (AMR). Each farm was visited once in July 2017 and the following environmental samples were collected: boot swabs from the alleyways of freestalls or the slurry passage in tie-stalls, pooled faecal samples from calf, and youngstock, pens (1–5 head per sample), and dust samples collected on dry gauze from 3-5 areas of the main cowshed. Samples were then cultured on selective media specific for MRSA or ESBL-EC detection. Results: MRSA in the dust samples was only isolated from one farm (2% of farms), whereas ESBL-producing E.coli were detected in at least one faecal sample on 13 of 50 farms (26%). The Mann-Whitney U test determined no statistically significant difference between the level of AMU (calculated as total DDDvet) on farms where ESBL-producing E.coli were detected, compared to those where all faecal samples were negative (U-score 189.0, asymptotic 2-tailed p = 0.255). Similarly, no difference was noted when the level of use of third and fourth generation cephalosporins only was compared with the presence of ESBL-producing E.coli (U-score 206.5, asymptotic 2-tailed p = 0.447). Due to the extremely low prevalence of MRSA in this farm population, statistical analyses would not be meaningful and were not done. Conclusion: MRSA was rarely detected, whereas ESBL-producing E.coli were isolated in around a quarter of 50 Austrian dairy farms. At this relatively low level of AMU in a small sample of Austrian dairy farms, no relationship between AMU and the presence of ESBL-EC could be demonstrated.

In Austria, all laboratories are legally obligated to forward human and food/environmental L. monocytogenes isolates to the National Reference Laboratory/Center (NRL) for Listeria. Two invasive human isolates of L. monocytogenes serotype 1/2a of the same pulsed-field gel electrophoresis (PFGE) pattern, previously unknown in Austria, were cultured for the first time in January 2016. Five further human isolates, obtained from patients with invasive listeriosis between April 2016 and September 2017, showed this PFGE pattern. In Austria the NRL started to use whole-genome sequencing (WGS) based typing in 2016, using a core genome MLST (cgMLST) scheme developed by Ruppitsch et al. 2015, which contains 1701 target genes. Sequence data are submitted to a publicly available nomenclature server (Ridom GmbH, Münster, Germany) for allocation of the core genome complex type (CT). The seven invasive human isolates differed from each other with zero to two alleles and were allocated to CT1234 (declared as outbreak strain). Among the Austrian strain collection of about 6,000 cgMLST-characterized non-human isolates (i.e., food/environmental isolates) 90 isolates shared CT1234. Out of these, 83 isolates were traced back to one meat processing-company. They differed from the outbreak strain by up to seven alleles; one isolate originated from the company's industrial slicer. The remaining seven CT1234-isolates were obtained from food products of four other companies (five fish-products, one ready-to-eat dumpling and one deer-meat) and differed from the outbreak strain by six to eleven alleles. The outbreak described shows the considerable potential of WGS to identify the source of a listeriosis outbreak. Compared to PFGE analysis, WGS-based typing has higher discriminatory power, yields better data accuracy, and allows higher laboratory through-put at lower cost. Utilization of WGS-based typing results of human and food/ environmental L. monocytogenes isolates by appropriate public health analysts and epidemiologists is indispensable to support a successful outbreak investigation.

In late December 2018, an outbreak of listeriosis occurred after a group of 32 individuals celebrated in a tavern in Styria, Austria; traditional Austrian food (e.g. meat, meat products and cheese) was served. After the celebration, 11 individuals developed gastrointestinal symptoms, including one case with severe sepsis. Cases had consumed mixed platters with several meat products and pâtés originating from a local production facility (company X). Human, food and environmental samples taken from the tavern and company X were tested for L. monocytogenes. Whole genome sequence-based typing detected a novel L. monocytogenes strain of serotype IVb, sequence type 4 and CT7652 in 15 samples; 12 human, two food and one environmental sample from company X with an allelic difference of 0 to 1. Active case finding identified two further cases who had not visited the tavern but tested positive for the outbreak strain. In total, 13 cases (seven females and six males; age range: 4-84 years) were identified. Liver pâté produced by company X was identified as the likely source of the outbreak. Control measures were implemented and since the end of December 2018, no more cases were detected.

Summary There is growing concern about human-induced antibiotic resistance and on the occurrence of antibiotic-resistant, potentially pathogenic bacteria in the environment. The aim of this study was to investigate the incidence of resistant, clinically relevant bacteria at bathing sites. In total, 27 of 263 bathing sites authorized under the EU Bathing Water Directive (3 per Austrian state) were sampled during the summer of 2017. Samples were tested for antibiotic-resistant bacteria by enrichment in thioglycollate broth and cultivation on chromogenic media. The screening for potentially pathogenic antibiotic-resistant bacteria was negative in 23 of the 27 samples. Antibiotic-resistant bacteria were detected from 4 of the 27 bathing sites: one Pseudomonas aeruginosa and three resistant Enterobacteriaceae (piperacillin/tazobactam-resistant Enterobacter cloacae with high-level expression of AmpC beta-lactamase, carbapenem-resistant Enterobacter mori, extended-spectrum beta-lactamase-producing Escherichia coli). Despite the occurrence of resistant bacteria, we consider the public health risk at Austrian bathing sites as low.

In 2016, the Austrian Agency for Health and Food Safety started a pilot project to investigate antimicrobial resistance in surface water. Here we report on the characterisation of carbapenem resistant and ESBL-producing K. pneumoniae isolates from Austrian river water samples compared to 95 clinical isolates recently obtained in Austrian hospitals. Ten water samples were taken from four main rivers, collected upstream and downstream of major cities in 2016. For subtyping and comparison, public core genome multi locus sequence typing (cgMLST) schemes were used. The presence of AMR genes, virulence genes and plasmids was extracted from whole genome sequence (WGS) data. In total three ESBL-producing strains and two carbapenem resistant strains were isolated. WGS based comparison of these five water isolates to 95 clinical isolates identified three clusters. Cluster 1 (ST11) and cluster 2 (ST985) consisted of doublets of carbapenem resistant strains (one water and one clinical isolate each). Cluster 3 (ST405) consisted of three ESBL-producing strains isolated from one water sample and two clinical specimens. The cities, in which patient isolates of cluster 2 and 3 were collected, were in concordance with the water sampling locations downstream from these cities. The genetic concordance between isolates from river water samples and patient isolates raises concerns regarding the release of wastewater treatment plant effluents into surface water. From a public health perspective these findings demand attention and strategies are required to minimize the spread of multiresistant strains to the environment.

The increasing emergence of multi-resistant bacteria in healthcare settings, in the community and in the environment represents a major health threat worldwide. In 2016, we started a pilot project to investigate antimicrobial resistance in surface water. Bacteria were enriched, cultivated on selective chromogenic media and species identification was carried out by MALDI-TOF analysis. From a river in southern Austria a methicillin resistant Staphylococcus aureus (MRSA) was isolated. Whole genome sequence analysis identified the isolate as ST8, spa type t008, SCCmecIV, PVL and ACME positive, which are main features of CA-MRSA USA300. Whole genome based cgMLST of the water isolate and comparison to 18 clinical MRSA USA300 isolates from the Austrian national reference laboratory for coagulase positive staphylococci originating from 2004, 2005 and 2016 and sequences of 146 USA300 isolates arbitrarily retrieved from the Sequence Read Archive revealed a close relatedness to a clinical isolate from Austria. The presence of a CA-MRSA USA300 isolate in an aquatic environment might pose a public health risk by serving as a potential source of infection or a source for emergence of new pathogenic MRSA clones.

Despite their general low incidence, Shiga toxin-producing Escherichia (E.) coli (STEC) infections are considered an important public health issue due to the severity of illness that can develop, particularly in young children. We report on two Austrian petting zoos, one in Tyrol (2015) and one in Vorarlberg (2016), which were identified as highly likely infection sources of STEC infections. The petting zoo related cases involved a case of hemolytic uremic syndrome (HUS) due to STEC O157:HNM in 2015 and an outbreak of STEC O157:H7 infections affecting five young children and two adults in 2016. The HUS case accounted for 2.8% of the 36 STEC O157:HNM/H7 infections notified in Austria in 2015 (5,9% of 17 HUS cases). The seven cases described for 2016 accounted for 4.0% of the 177 human STEC infections documented for Austria in 2016, and for 19.4% of the 36 STEC O157:HNM/H7 infections notified that year. The evaluation of the STEC infections described here clearly underlines the potential of sequence-based typing methods to offer suitable resolutions for public health applications. Furthermore, we give a state-of-the-art mini-review on the risks of petting zoos concerning exposure to the zoonotic hazard STEC and on proper measures of risk-prevention.

Summary In 2015, 119.2 t of active ingredients of antibiotics were used in Austria in human medicine (70.4 t; 59.1%), for food animals (48.8 t; 40.9%) and in plant production (0.002 t; < 0.1%). During the last five years, consumption of antibiotics increased in human medicine by 3.8% (2011: 67.8 t; 2015: 70.4 t). In hospitals, it increased by 17.3%, from 19.7 t in 2011 to 23.1 t active ingredients in 2015. In the community, measured in kg active ingredient, it increased by 0.3% from 2011 to 2015. Consumption in defined daily dose (DDD) per 100,000 inhabitants per year decreased by 3.6%. Our numbers for the community (2015: 17.0 DDD) contradict AURES reports and a recent ECDC report, which claim a consumption of 14.0 DDD/1000 inhabitants per day in primary care in Austria, based on the social insurance company’s sales data. Declining pharmacy sales prices due to an increase in market shares for cheap generic drugs as well as increase in deductibles for insured people falsely suggest low consumption. In food animals, the antibiotic consumption decreased by 8.7%, from 53.4 t to 48.8 t. In plant production, the annual usage fluctuated considerably and decreased by 95.3%, from 47.2 kg in 2010 to 2.2 kg in 2015.

ABSTRACT The increasing emergence of multiresistant bacteria in health care settings in the community and in the environment represents a major health threat worldwide. Here, we report the draft genome sequence of a community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) USA300 isolate (W1) from a small river in southern Austria.

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The emergence and spread of carbapenem-resistant Enterobacteriaceae (CRE) are a global health problem that is of great concern to public health services (1, 2). The purpose of this study was to determine the frequency of CRE in three Nigerian hospitals and to characterize the resistance mechanisms of such isolates. A total of 218 consecutive clinical isolates of Enterobacteriaceae based on inclusion criteria were collected from March to May 2015 at three medical microbiology laboratories of hospitals in Edo State, Nigeria (see Table S1 in the supplemental material). Screening for carbapenem resistance was performed using meropenem and ertapenem discs (10 g; Oxoid, United Kingdom) according to EUCAST guidelines (3). The KirbyBauer susceptibility testing technique (4) and Etest method were carried out, and results were interpreted using EUCAST criteria (5). Identification of the involved resistance mechanisms was determined by whole-genome sequencing (WGS). Out of 218 consecutive clinical Enterobacteriaceae isolates, 9 (4.1%) were further investigated due to cutoff values above the EUCAST screening recommendations (Table 1). All isolates showed resistance to piperacillin-tazobactam and amoxicillin-clavulanic acid, all but isolate Ec4349 showed resistance to fluoroquinolones and cefotaxime, and all but two isolates each showed resistance to ceftazidime (Ec4349 and Ecl2840_1) and ertapenem (Ec4349 and Ecl10_14_15). Only Ec4349, Ecl2845, Ecl2840_1, and EclQ9 were sensitive to cefepime and aztreonam. The carbapenemase inactivation method (6) revealed positive results for all nine CRE isolates. By application of WGS, one Klebsiella pneumoniae isolate harbored the blaOXA-181 gene; two K. pneumoniae isolates harbored the blaNDM-1 gene. The blaOXA-48 gene was detected in one Escherichia coli isolate, one K. pneumoniae isolate, and four Enterobacter cloacae isolates, respectively. All isolates had a single carbapenemase resistance gene on their draft genome fragment. Thirteen plasmid incompatibility groups were identified among the nine CRE isolates. Multilocus sequence typing (MLST) grouped the nine isolates into five sequence types. Previous reports from Nigeria on molecular characterization of carbapenem resistance genes have identified genes such as blaVIM, blaGES, blaNDM, blaOXA-181, and blaKPC (7–10). blaOXA-48, obtained from our study, has only been determined phenotypically. To the best of our knowledge, our findings, where six out of nine carbapenemaseproducing isolates harbored the blaOXA-48 gene, represent the first molecular determination of the blaOXA-48 gene for Nigeria. The presence of different plasmid replicon types in carbapenemase-producing Enterobacteriaceae (CPE) underlines their importance in the dissemination of resistance genes. The IncL/M plasmid type was found in all of our OXA-48-producing isolates, correlating with previous reports indicating that Accepted manuscript posted online 12 June 2017 Citation Jesumirhewe C, Springer B, Lepuschitz S, Allerberger F, Ruppitsch W. 2017. Carbapenemase-producing Enterobacteriaceae isolates from Edo State, Nigeria. Antimicrob Agents Chemother 61:e00255-17. https://doi .org/10.1128/AAC.00255-17. Copyright © 2017 Jesumirhewe et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. Address correspondence to Christiana Jesumirhewe, ebarunosen2002@yahoo.co.uk. LETTER TO THE EDITOR