Carbapenemase-producing Enterobacterales Isolates Research Articles

Molecular epidemiology and the clinical impact of carbapenemase-producing Enterobacterales isolates among adult patients: aspects from a Romanian non-teaching hospital

Abstract Introduction: A dramatic increase of infections induced by carbapenemase-producing Enterobacterales (CPE) has been registered worldwide. The aim of this study was to evaluate the molecular epidemiology and the clinical impact of CPE strains isolated from adult inpatients. Material and methods: A one-year, single-center, retrospective observational study including 34 consecutive patients with 37 non-duplicate CPE strains recovered from clinical specimens was accomplished. The Vitek 2 Compact, M.I.C.Evaluator strips, the modified carbapenem inactivation method (mCIM), and the combination disks test (KPC, MBL, OXA-48 Confirm kit, Rosco Diagnostica) were applied as phenotypic tests. A multiplex polymerase chain reaction (PCR) assay was used for detection of blaKPC, blaNDM, and blaOXA-48-like genes. The clonality was assessed with pulsed-field gel electrophoresis (PFGE). Results: Klebsiella pneumoniae (n=25) was the most frequent CPE encountered. The carbapenemase types were NDM (n=13), KPC (n=12), and OXA-48-like (n=12). Two distinct clonal clusters were identified among the 12 KPC positive strains. All CPE isolates exhibited non-susceptibility to carbapenems, cephalosporins, ciprofloxacin. Respiratory tract infections (n=16) and hospitalization in the intensive care unit (ICU) (n=14) were dominant. The most common comorbidity was congestive heart failure (n=11). Monotherapy was the main strategy adopted (n=15). Death occurred in 18 patients. Conclusions: Our analysis underscores the scarcity of antibiotic solutions and high mortality. Monotherapy for urinary tract infections (UTIs) is beneficial. Inter- or intrahospital dissemination of successful epidemic clones is proved. The adequate CPE infections control programs and antimicrobial policies are essential..

Carbapenemase-producing Enterobacterales in hospital drains in Southern Ontario, Canada

Hospital drains may be an important reservoir for carbapenemase-producing Enterobacterales (CPE). To determine prevalence of CPE in hospital drains exposed to inpatients with CPE, relatedness of drain and patient CPE, and risk factors for drain contamination. Sink and shower drains in patient rooms and communal shower rooms exposed to 310 inpatients with CPE colonization/infection were cultured at 10 hospitals. Using short- and long-read whole-genome sequencing, inpatient and corresponding drain CPE were compared. Risk factors for drain contamination were assessed using multi-level modelling. Of 1209 exposed patient room and communal shower room drains, 53 (4%) yielded 62 CPE isolates in seven (70%) hospitals. Of 49 CPE isolates in patient room drains, four (8%) were linked to prior room occupants. Linked drain/room occupant pairs included Citrobacter freundii ST18 isolates separated by eight single nucleotide variants (SNVs), related blaKPC-containing IncN3-type plasmids (different species), related blaKPC-3-containing IncN-type plasmids (different species), and related blaOXA-48-containing IncL/M-type plasmids (different species). In one hospital, drain isolates from eight rooms on two units were Enterobacter hormaechei separated by 0-6 SNVs. Shower drains were more likely to be CPE-contaminated than hand hygiene (odds ratio: 3.45; 95% confidence interval: 1.66-7.16) or patient-use (13.0; 4.29-39.1) sink drains. Hand hygiene sink drains were more likely to be CPE-contaminated than patient-use sink drains (3.75; 1.17-12.0). Drain contamination was uncommon but widely dispersed. Drain CPE unrelated to patient exposure suggests contamination by undetected colonized patients or retrograde (drain-to-drain) contamination. Drain types had different contamination risks.

Detecting carbapenemase-producing Enterobacterales (CPE): an evaluation of an enhanced CPE infection control and screening programme in acute care.

The transmission of carbapenemase-producing Enterobacterales (CPE) poses an increasing healthcare challenge. A range of infection prevention activities, including screening and contact precautions, are recommended by international and national guidelines. We evaluated the introduction of an enhanced screening programme in a multisite London hospital group. In June 2015, an enhanced CPE policy was launched in response to a local rise in CPE detection. This increased infection prevention measures beyond the national recommendations, with enhanced admission screening, contact tracing and environmental disinfection, improved laboratory protocols and staff/patient education. We report the CPE incidence and trends of CPE in screening and clinical cultures and the adoption of enhanced CPE screening. All non-duplicate CPE isolates identified between April 2014 and March 2018 were included. The number of CPE screens increased progressively, from 4530 in July 2015 to 10 589 in March 2018. CPE detection increased from 18 patients in July 2015 (1.0 per 1000 admissions) to 50 patients in March 2018 (2.7 per 1000 admissions). The proportion of CPE-positive screening cultures remained at approximately 0.4% throughout, suggesting that whilst the CPE carriage rate was unchanged, carrier identification increased. Also, 123 patients were identified through positive CPE clinical cultures over the study period; there was no significant change in the rate of CPE from clinical cultures per 1000 admissions (P = 0.07). Our findings suggest that whilst the enhanced screening programme identified a previously undetected reservoir of CPE colonization in our patient population, the rate of detection of CPE in clinical cultures did not increase.

Genomic analysis of a multidrug-resistant Klebsiella pneumoniae ST11 strain recovered from Barbary deer (Cervus elaphus barbarus) in Akfadou Forest, Algeria

ObjectivesThe emergence and worldwide spread of carbapenemase-producing Enterobacterales (CPE) is a great public-health concern. This study aimed to screen for the presence of CPE isolates from Barbary deer in Akfadou Forest, Béjaïa (Algeria). MethodsFaecal samples (n=39) were obtained from Barbary deer in Akfadou Forest between March–June 2018. Whole-genome sequencing (WGS) was performed to characterise one representative strain of Klebsiella pneumoniae. Data analysis was performed using online tools. ResultsA total of 13 carbapenem-resistantK. pneumoniae isolates were obtained. The isolates showed an identical antimicrobial resistance pattern and were susceptible to colistin and fosfomycin. WGS analysis revealed the complete resistome of K. pneumoniae strain CF21, including blaNDM-1, blaCTX-M-15, blaSHV-182, blaDHA-1, blaOXA-1, aac(3)-IIa, aac(3)-IId, aac(6ʹ)-Ib-cr, rmtC, sul1, qnrB9, fosA, tetA, dfrA14, catA2, catB3 and mphA. Multilocus sequence typing (MLST) analysis assigned this strain to the international clone ST11. Plasmid analysis showed that this K. pneumoniae strain possesses five different plasmids including IncA/C2, IncFIA(HI1), IncFIB(K), IncFII(K) and ColRNAI. ConclusionThis study reports a multidrug-resistantK. pneumoniae strain recovered from Barbary deer in Algeria and confirms that wild animals could serve as a reservoir of antimicrobial resistance genes.

Prospective evaluation of an easy and reliable work flow for the screening of OXA-48-producing Klebsiella pneumoniae in endemic settings

Carbapenemase-producing Enterobacterales (CPE) represent a serious threat to public health. Clinical microbiology laboratories (CMLs) need effective protocols for screening and confirmation of CPE. To prospectively evaluate an algorithm for the screening of carbapenemase-producing Klebsiella pneumoniae in an OXA-48 endemic hospital. The algorithm was based on a disc diffusion assay using ertapenem and temocillin, which also served as a purity check for routine automated antimicrobial susceptibility testing. All isolates with minimal inhibitory concentrations >0.5 mg/L or zone inhibition diameters <25 mm for ertapenem (Criterion 1) and <12 mm for temocillin (Criterion 2) were tested sequentially by an OXA-48 lateral flow immunochromatographic assay and a multiplex polymerase chain reaction targeting VIM, KPC and OXA-48. If neither test was positive, the modified Hodge test or CARBA NP test was used. Over 2 years, 2487 K.pneumoniae were assessed by the algorithm proposed, and 378 (15.20%) met both criteria. Of these, 98.68% (373/378) were either confirmed as OXA-48 producers or originated from patients with a previous CPE isolate that maintained the same resistance phenotype over time. The remaining three K.pneumoniae were VIM producers. Only two of the 378 isolates (0.53%) did not produce carbapenemase, despite meeting Criteria 1 and 2. The algorithm described combined the most sensitive carbapenem for CPE detection with a cut-off for temocillin that was highly specific for detection of OXA-48. It is reliable and easy to apply in routine CML work flow, allowing rapid detection of CPE isolates and hence prompt implementation of infection control measures and targeted antimicrobial regimens.

In vitro susceptibility of OXA-48, NDM, VIM and IMP enzyme- producing Klebsiella spp. and Escherichia coli to fosfomycin.

Infections caused by Carbapenemase-producing Enterobacterales (CPE) are an important public health issue. Intravenous fosfomycin can be considered as an alternative for the treatment of serious infections caused by CPE. In this study, in vitro activity of fosfomycin was investigated among CPE isolates. Overall, 158 clinically relevant isolates obtained from 18 hospitals of 13 cities in Turkey with predetermined carbapenemase types were evaluated in the study, including Escherichia coli (n = 19) and Klebsiella spp. (n = 139). In vitro activity of fosfomycin was determined with agar dilution method. Among Klebsiella spp., 104 harbored blaOXA-48, 15 isolates carried both blaOXA-48 and blaNDM; three had both blaOXA-48 and blaVIM and nine isolates had blaNDM alone. Four isolates carried only blaVIM and two isolates harbored blaIMP alone. One isolate co-harbored blaVIM and blaNDM. Among E. coli isolates, blaOXA-48 and blaNDM were carried by 18 and one isolates, respectively. Resistance to fosfomycin was detected in 43.7% of the isolates. Among Klebsiella spp. and E. coli, these rates were 46.8% and 21.1%, respectively. In Klebsiella spp. resistance to fosfomycin was 49.5% in blaOXA-48 carriers; 26.7% in isolates co-harbouring blaOXA-48 and blaNDM and 66.7% in blaNDM carriers. In E. coli, fosfomycin resistance was detected among 16.7% of the blaOXA-48 carriers. High level of fosfomycin resistance in these isolates may be attributable to the fact that these isolates are multidrug resistant. The genetic background of resistance should also be investigated in order to understand the co-occurrence and transfer of resistance among the CPE.

Temporal and regional incidence of carbapenemase-producing Enterobacterales, Switzerland, 2013 to 2018.

IntroductionIn contrast to countries where carbapenemase-producing Enterobacterales (CPE) are endemic, only sporadic cases were reported in Switzerland until 2013. An aggravation of the epidemiological situation in neighbouring European countries indicated the need for a surveillance study in Switzerland.AimWe aimed to describe CPE distributions in Switzerland and identify epidemiological factors associated with changes in incidence.MethodsData on all human CPE isolates from 2013 to 2018 were collected by the Swiss Centre for Antibiotic Resistance (ANRESIS) and analysed for temporal and regional trends by Generalised Poisson regression. Isolates associated with infection or colonisation were included in a primary analysis; a secondary analysis included invasive isolates only. Statistical detection of regional clusters was performed with WHONET/SaTScan.ResultsWe analysed 731 CPE isolates, of which 325 (44.5%) were associated with screenings and 173 (23.7%) with infections. Yearly detection of CPE isolates increased considerably during the study period from 65 to 212. The most frequently isolated species were Klebsiella pneumoniae (54%) and Escherichia coli (28%). The most frequent genotypes were OXA-48 (43%), KPC (21%) and NDM (14%). In contrast to the French-speaking parts of Switzerland (West, Geneva) where OXA-48 were the predominant genotypes (around 60%), KPC was the most frequently detected genotype in the Italian-speaking region (63%). WHONET/SaTScan outbreak detection analysis identified seven clusters in five regions of Switzerland.ConclusionsIn a first continuous surveillance of CPE in Switzerland, we found that the epidemiological situation aggravated nationwide and that regional patterns of CPE genotypes mirrored the situation in neighbouring European countries.

Molecular characteristics of carbapenemase-producing Enterobacterales in the Netherlands; results of the 2014–2018 national laboratory surveillance

ObjectivesCarbapenem resistance mediated by mobile genetic elements has emerged worldwide and has become a major public health threat. To gain insight into the molecular epidemiology of carbapenem resistance in The Netherlands, Dutch medical microbiology laboratories are requested to submit suspected carbapenemase-producing Enterobacterales (CPE) to the National Institute for Public Health and the Environment as part of a national surveillance system. MethodsMeropenem MICs and species identification were confirmed by E-test and MALDI-TOF and carbapenemase production was assessed by the Carbapenem Inactivation Method. Of all submitted CPE, one species/carbapenemase gene combination per person per year was subjected to next-generation sequencing (NGS). ResultsIn total, 1838 unique isolates were received between 2014 and 2018, of which 892 were unique CPE isolates with NGS data available. The predominant CPE species were Klebsiella pneumoniae (n = 388, 43%), Escherichia coli (n = 264, 30%) and Enterobacter cloacae complex (n = 116, 13%). Various carbapenemase alleles of the same carbapenemase gene resulted in different susceptibilities to meropenem and this effect varied between species. Analyses of NGS data showed variation of prevalence of carbapenemase alleles over time with blaOXA-48 being predominant (38%, 336/892), followed by blaNDM-1 (16%, 145/892). For the first time in the Netherlands, blaOXA-181, blaOXA-232 and blaVIM-4 were detected. The genetic background of K. pneumoniae and E. coli isolates was highly diverse. ConclusionsThe CPE population in the Netherlands is diverse, suggesting multiple introductions. The predominant carbapenemase alleles are blaOXA-48 and blaNDM-1. There was a clear association between species, carbapenemase allele and susceptibility to meropenem.

Intestinal co-colonization with different carbapenemase-producing Enterobacterales isolates is not a rare event in an OXA-48 endemic area

BackgroundThe current spread of carbapenemase-producing Enterobacterales (CPE) is a great concern. MethodsWe recovered 198 CPE from 162 patients admitted in our Hospital (March 2014-March 2016) during the R-GNOSIS European Project. Microbiological features and plasmid characteristics of CPE recovered from patients co-colonized with multiple CPE were studied. FindingsThirty patients (18.5%; CI 95%= 12.5%–24.5%) presented co-colonization with multiple CPE producing the same (CPE-SC) (15.4%) or a different carbapenemase (CPE-DC) (4.3%). OXA-48 (83.3%) was the most frequent carbapenemase, followed by VIM-1 (26.7%), NDM-1 (10%) and KPC-3 (3.3%). CPE-DC-patients had longer admissions [63 days (20–107)] than the other patients. Moreover, hospital stay until CPE detection was lower [9 days (5–14)] (p = 0.0052) in CPE-SC-patients than in those with a single colonization; 56% showed co-colonization in the first positive sample, although most of them had previous admissions and had received multiple antibiotic treatments. CPE were more frequently recovered in clinical samples from co-colonized [CPE-DC (28.6%), CPE-SC (24%)] patients than from patients with a single CPE (15.2%). Among CPE-SCOXA-48 [80% (p = 0.11)], K. pneumoniae [88% (p = 0.006)] and E. coli [84% (p < 0.001)] were the most frequent species. In 60% of patients, K. pneumoniae and E. coli species were simultaneously recovered, frequently after a single OXA-48-K. pneumoniae colonization. High-risk clones (ST11, ST15, ST307) were detected in OXA-48-K. pneumoniae but a higher clonal diversity was found among E. coli. A frequent in-vivo cross-species plasmid transmission was shown, due to a dominant plasmid (IncL-pOXA-48), but also involving related or unrelated blaVIM-1-, blaNDM-1- and blaKPC-3-encoding plasmids. InterpretationCPE co-colonization status should be monitored during epidemiological surveillance cultures, as these patients might be at a higher risk for infection. FundingEuropean Commission Framework Programme 7 and Instituto de Salud Carlos III, Spain