High prevalence of multidrug-resistant Gram-negative bacteria carriage in children screened prospectively for multidrug resistant organisms at admission to a paediatric hospital, Hamburg, Germany, September 2018 to May 2019.

BackgroundIncreasing resistance to antibiotics poses medical challenges worldwide. Prospective data on carriage prevalence of multidrug resistant organisms (MDRO) in children at hospital admission are limited and associated risk factors are poorly defined.AimTo determine prevalence of MDRO carriage in children at admission to our paediatric hospital in Hamburg and to identify MDRO carriage risk factors.MethodsWe prospectively obtained and cultured nasal/throat and inguinal/anal swabs from children (≤ 18 years) at admission between September 2018 and May 2019 to determine prevalence of meticillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Gram-negative bacteria (MRGN) and vancomycin-resistant enterococcus (VRE) and associated species. We collected medical histories using a questionnaire and evaluated 31 risk factors using logistic regression models.ResultsMDRO carriage prevalence of 3,964 children was 4.31% (95% confidence interval (CI): 3.69-5.00). MRSA carriage prevalence was 0.68% (95% CI: 0.44-0.99), MRGN prevalence was 3.64% (95% CI: 3.07-4.28) and VRE prevalence 0.08% (95% CI: 0.02-0.22). MDRO carriage was associated with MRGN history (odds ratio (OR): 6.53; 95% CI: 2.58-16.13), chronic condition requiring permanent care (OR: 2.67; 95% CI: 1.07-6.13), antibiotic therapy (OR: 1.92, 95% CI: 1.24-2.94), living in a care facility (OR: 3.34; 95% CI: 0.72-12.44) and refugee status in previous 12 months (OR: 1.91; 95% CI: 0.27-8.02). Compared to established practice, screening using risk-factors had better diagnostic sensitivity (86.13%; 95% CI: 80.89-91.40) and specificity (73.54%; 95% CI: 72.12-74.97).ConclusionMRGN carriage was higher than MRSA and VRE. Extended risk-factor-based admission screening system seems warranted.

Comparison of MICs in Escherichia coli isolates from human health surveillance with MICs obtained for the same isolates by broth microdilution.

OBJECTIVES: Human health surveillance and food safety monitoring systems use different antimicrobial susceptibility testing (AST) methods. In this study, we compared the MICs of Escherichia coli isolates provided by these methods. METHODS: E. coli isolates (n = 120) from human urine samples and their MICs were collected from six medical laboratories that used automated AST methods based on bacterial growth kinetic analyses. These isolates were retested using broth microdilution, which is used by the food safety monitoring system. The essential and categorical agreements (EA and CA), very major errors (VME), major errors (ME) and minor errors (mE) for these two methods were calculated for 11 antibiotics using broth microdilution as a reference. For statistical analysis, clinical breakpoints provided by EUCAST were used. RESULTS: Five study laboratories used VITEK®2 and one MicroScan (Walkaway Combo Panel). Out of 120 isolates, 118 isolates (98.3%) were confirmed as E. coli. The 99 E. coli isolates from five study laboratories that used VITEK®2 showed high proportions of EA and CA with full agreements for gentamicin, meropenem, imipenem and ertapenem. Additionally, 100% CA was also observed in cefepime. Few VME (0.5%), ME (1.9%) and mE (1.5%) were observed across all antibiotics. One VME for ceftazidime (7.1%) and 12 MEs for ampicillin (29.4%), cefotaxime (2.4%), ciprofloxacin (3.2%), tigecycline (1.5%) and trimethoprim (22.2%) were detected. CONCLUSIONS: MICs from E. coli isolates produced by VITEK®2 were similar to those determined by broth microdilution. These results will be valuable for comparative analyses of resistance data from human health surveillance and food safety monitoring systems.

First report of Escherichia coli co-producing NDM-1 and OXA-232.

Recently Gram-negative bacteria co-producing multiple carbapenemases have emerged in different parts of the world. We report the first isolation of an Escherichia coli strain co-producing the carbapenemases NDM-1 and OXA-232.

Multicentre investigation of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in German hospitals.

Aim of this study was to determine the incidence and molecular epidemiology of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in Germany. E. coli and K. pneumoniae isolates from clinical samples which were non-susceptible to carbapenems were collected in laboratories serving 20 hospitals throughout Germany from November 2013 to April 2014. The isolates were tested for the presence of carbapenemases by PCR and phenotypic methods and typed by multilocus sequence typing. Risk factors including a previous hospitalization abroad were analysed. Carbapenemases were detected in 24 isolates from 22 patients out of 464,514 admissions. Carbapenemases included OXA-48 (n=14), KPC-2 (n=8) and NDM-1 (n=2). Except for two K. pneumoniae isolates with ST101, all OXA-48 producing strains belonged to different clones. In contrast, half of KPC-2 producing K. pneumoniae were of ST258 and both NDM-1 producing strains were of ST11. Compared to carbapenem-susceptible controls, patients with carbapenemase-producing strains differed by a significantly higher proportion of males, a higher proportion of isolates from wound samples and a more frequent previous stay abroad in univariate analysis. This multicentre study demonstrated an incidence of carbapenemase-producing E. coli and K. pneumoniae from clinical samples in Germany of 0.047 cases per 1000 admissions. OXA-48 was more frequent than KPC-2 and NDM-1 and showed a multiclonal background.

Linezolid resistance in clinical isolates of Staphylococcus epidermidis from German hospitals and characterization of two cfr-carrying plasmids.

OBJECTIVES: This study was a detailed investigation of Staphylococcus epidermidis clinical isolates exhibiting linezolid resistance. METHODS: Thirty-six linezolid-resistant S. epidermidis from eight German hospitals, including isolates from suspected hospital-associated outbreaks between January 2012 and April 2013, were analysed with respect to their antimicrobial susceptibility and the presence of cfr and/or mutations in the 23S rRNA, rplC, rplD and rplV genes. Relatedness of isolates was estimated by MLST and SmaI macrorestriction analysis. Characterization of cfr plasmids was carried out by means of Illumina sequencing. RESULTS: The MICs of linezolid varied substantially between the isolates. No apparent correlation was detected between the level of resistance, the presence of cfr and ribosomal target site mutations. S. epidermidis isolates from two hospitals were confirmed as clonally related, indicating the spread of the respective clone over a period of 1 year. Next-generation sequencing revealed two different categories of cfr-expressing plasmids, both of them varying in genetic arrangement and composition from previously published cfr plasmids: p12-00322-like plasmids showed incorporation of cfr into a pGO1-like backbone and displayed capabilities for intra- and inter-species conjugational transfer. CONCLUSIONS: To date, linezolid-resistant S. epidermidis have rarely been isolated from human clinical sources in Germany. Here, we describe the emergence and outbreaks of these strains. We detected previously described and novel point mutations in the 23S ribosomal genes. The cfr gene was only present in six isolates. However, this is the first known description of cfr incorporation into conjugative vectors; under selective pressure, these vectors could give reasonable cause for concern.

Prevalence and genotypes of extended spectrum beta-lactamases in Enterobacteriaceae isolated from human stool and chicken meat in Hamburg, Germany.

Chicken meat has been proposed to constitute a source for extended spectrum beta-lactamase (ESBL)-carrying Enterobacteriaceae that colonize and infect humans. In this study the prevalence of ESBL-producing Enterobacteriaceae in stool samples from ambulatory patients who presented in the emergency department of the University Medical Centre Hamburg-Eppendorf with gastrointestinal complains and in chicken meat samples from the Hamburg region were analysed and compared with respect to ESBL-genotypes, sequence types and antibiotic resistance profiles. Twenty-nine (4.1%) of 707 stool samples and 72 (60%) of 120 chicken meat samples were positive for ESBL-producing Enterobacteriaceae. The distribution of ESBL genes in the stool vs. chicken meat isolates (given as % of total isolates from stool vs. chicken meat) was as follows: CTX-M-15 (38% vs. 0%), CTX-M-14 (17% vs. 6%), CTX-M-1 (17% vs. 69%), SHV-12 (3% vs. 18%) and TEM-52 (3% each). Comparison of ESBL- and multilocus sequence type revealed no correlation between isolates of human and chicken. Furthermore, ESBL-producing E. coli from stool samples were significantly more resistant to fluoroquinolones, aminoglycosides and/or trimethoprim-sulfamethoxazole than chicken isolates. The differences in ESBL-genotypes, sequence types and antibiotic resistance patterns indicate that in our clinical setting chicken meat is not a major contributor to human colonization with ESBL-carrying Enterobacteriaceae.