Pilot study on nasal microbiota dynamics and MRSA carriage of a pig cohort housed on straw bedding

Methicillin-resistant Staphylococcus aureus (MRSA) can be transmitted between pigs and humans on farms. Hence, the reduction of MRSA carriage in pigs could decrease the risk of zoonotic transmission. Recently, straw bedding has been found to significantly reduce MRSA carriage in pigs. The mechanisms behind this effect remain unclear but changes in the nasal microbiome may play a role. In this exploratory study, the nasal microbiota of pigs kept on straw was examined using V1/V2 16S rRNA gene sequencing. Nasal swabs were collected from 13 pigs at six different time points during the course of a full fattening cycle resulting in 74 porcine samples. In addition, straw samples were collected at each time point. Eleven out of 13 pigs were MRSA positive at housing-in. We found a strong temporal pattern in the microbial communities. Both microbial diversity and abundance of Staphylococcus species peaked in week 5 after introduction to the straw stable decreased in week 10, when all pigs turned MRSA-negative, and increased again toward the end of the fattening period. These findings show that the introduction of pigs into a new environment has a huge impact on their nasal microbiota, which might lead to unfavorable conditions for MRSA. Moreover, other Staphylococcus species may play a role in eliminating MRSA carriage. We designed a follow-up study including two different husbandry systems to further assess these effects.

Epidemiology and zoonotic transmission of mcr-positive and carbapenemase-producing Enterobacterales on German turkey farms

Introduction

The emergence of carbapenem-resistant bacteria causing serious infections may lead to more frequent use of previously abandoned antibiotics like colistin. However, mobile colistin resistance genes (mcr) can jeopardise its effectiveness in both human and veterinary medicine. In Germany, turkeys have been identified as the food-producing animal most likely to harbour mcr-positive colistin-resistant Enterobacterales (mcr-Col-E). Therefore, the aim of the present study was to assess the prevalence of both mcr-Col-E and carbapenemase-producing Enterobacterales (CPE) in German turkey herds and humans in contact with these herds.

Methods

In 2018 and 2019, 175 environmental (boot swabs of turkey faeces) and 46 human stool samples were analysed using a combination of enrichment-based culture, PCR, core genome multilocus sequence typing (cgMLST) and plasmid typing.

Results

mcr-Col-E were detected in 123 of the 175 turkey farms in this study (70.3%). mcr-Col-E isolates were Escherichia coli (98.4%) and Klebsiella spp. (1.6%). Herds that had been treated with colistin were more likely to harbour mcr-Col-E, with 82.2% compared to 66.2% in untreated herds (p = 0.0298). Prevalence also depended on husbandry, with 7.1% mcr-Col-E in organic farms compared to 74.5% in conventional ones (p < 0.001). In addition, four of the 46 (8.7%) human participants were colonised with mcr-Col-E. mcr-Col-E isolates from stables had minimum inhibitory concentrations (MICs) from 4 to ≥ 32 mg/l, human isolates ranged from 4 to 8 mg/l. cgMLST showed no clonal transmission of isolates. For one farm, plasmid typing revealed great similarities between plasmids from an environmental and a human sample. No CPE were found in turkey herds or humans.

Discussion

These findings confirm that mcr-Col-E-prevalence is high in turkey farms, but no evidence of direct zoonotic transmission of clonal mcr-Col-E strains was found. However, the results indicate that plasmids may be transmitted between E. coli isolates from animals and humans.

[Therapy-relevant antibiotic resistances in a One Health context]

One Health refers to a concept that links human, animal, and environmental health. In Germany, there is extensive data on antibiotic resistance (AMR) and multidrug-resistant (micro)organisms (MDRO) in human and veterinary medicine, as well as from studies in various environmental compartments (soil, water, wastewater). All these activities are conducted according to different specifications and standards, which makes it difficult to compare data. A focus on AMR and MDRO of human therapeutic importance is helpful to provide some guidance. Most data are available across sectors on methicillin-resistant Staphylococcus aureus (MRSA) and multiresistant Enterobacterales such as Escherichia coli and Klebsiella pneumoniae. Here, the trends of resistance are heterogeneous. Antibiotic use leads to MRE selection, which is well documented. Success in minimizing antibiotic use has also been demonstrated in recent years in several sectors and could be correlated with success in containing AMR and MDRO (e.g., decrease in MRSA in human medicine). Sector-specific measures to reduce the burden of MDRO and AMR are also necessary, as not all resistance problems are linked to other sectors. Carbapenem resistance is still rare, but most apparent in human pathogens. Colistin resistance occurs in different sectors but shows different mechanisms in each. Resistance to antibiotics of last resort such as linezolid is rare in Germany, but shows a specific One Health correlation. Efforts to harmonize methods, for example in the field of antimicrobial susceptibility testing and genome-based pathogen and AMR surveillance, are an important first step towards a better comparability of the different data collections.

Clinical Evidence for the Use of Octenidine Dihydrochloride to Prevent Healthcare-Associated Infections and Decrease Staphylococcus aureus Carriage or Transmission-A Review

BACKGROUND

The antiseptic agent octenidine dihydrochloride (OCT) is used for skin preparation, for Staphylococcus aureus decolonization, and within bundles for the prevention of catheter-related or surgical site infections (SSIs). Here, we review the evidence for the effects of OCT from clinical studies.

METHODS

Review of studies published in the Medline, Scopus, and Cochrane databases until August 2022, performed in clinical settings and reporting on effects of OCT on S. aureus carriage/transmission, SSI prevention, and prevention of intensive care unit (ICU)-related or catheter-related bloodstream and insertion site infections.

RESULTS

We included 31 articles. The success of S. aureus decolonization with OCT-containing therapies ranged between 6 and 87%. Single studies demonstrated that OCT application led to a reduction in S. aureus infections, acquisition, and carriage. No study compared OCT for skin preparation before surgical interventions to other antiseptics. Weak evidence for the use of OCT for pre-operative washing was found in orthopedic and cardiac surgery, if combined with other topical measures. Mostly, studies did not demonstrate that daily OCT bathing reduced ICU-/catheter-related bloodstream infections with one exception.

CONCLUSIONS

There is a need to perform studies assessing the clinical use of OCT compared with other antiseptics with respect to its effectiveness to prevent nosocomial infections.

A prospective multicentre screening study on multidrug-resistant organisms in intensive care units in the Dutch-German cross-border region, 2017 to 2018: the importance of healthcare structures

Background

Antimicrobial resistance poses a risk for healthcare, both in the community and hospitals. The spread of multidrug-resistant organisms (MDROs) occurs mostly on a local and regional level, following movement of patients, but also occurs across national borders.

Aim

The aim of this observational study was to determine the prevalence of MDROs in a European cross-border region to understand differences and improve infection prevention based on real-time routine data and workflows.

Methods

Between September 2017 and June 2018, 23 hospitals in the Dutch (NL)–German (DE) cross-border region (BR) participated in the study. During 8 consecutive weeks, patients were screened upon admission to intensive care units (ICUs) for nasal carriage of meticillin-resistant Staphylococcus aureus (MRSA) and rectal carriage of vancomycin-resistant Enterococcus faecium/E. faecalis (VRE), third-generation cephalosporin-resistant Enterobacteriaceae (3GCRE) and carbapenem-resistant Enterobacteriaceae (CRE). All samples were processed in the associated laboratories.

Results

A total of 3,365 patients were screened (median age: 68 years (IQR: 57–77); male/female ratio: 59.7/40.3; NL-BR: n = 1,202; DE-BR: n = 2,163). Median screening compliance was 60.4% (NL-BR: 56.9%; DE-BR: 62.9%). MDRO prevalence was higher in DE-BR than in NL-BR, namely 1.7% vs 0.6% for MRSA (p = 0.006), 2.7% vs 0.1% for VRE (p < 0.001) and 6.6% vs 3.6% for 3GCRE (p < 0.001), whereas CRE prevalence was comparable (0.2% in DE-BR vs 0.0% in NL-BR ICUs).

Conclusions

This first prospective multicentre screening study in a European cross-border region shows high heterogenicity in MDRO carriage prevalence in NL-BR and DE-BR ICUs. This indicates that the prevalence is probably influenced by the different healthcare structures.

[Generation of an FAQ page on Dealing with Multi-resistant Pathogens at the Interface of Veterinary and Human Medicine]

OBJECTIVE

The aims of this work were the systematic and evidence-based generation and answering of frequently asked questions (FAQ) regarding contact with multi-drug resistant pathogens (MDR) including aspects of veterinary and human medicine for the public health service (PHS) and the general population.

METHODS

In order to determine the information needs of the population, guideline-based expert interviews with veterinarians and physicians were conducted in five surveys. In addition, information about the project was published in two journals and the participants were asked to submit open questions from their daily routine with respect to MDR. The results of the interviews and project calls were divided into categories, and frequently mentioned topics were prepared as FAQ. For answering the FAQ, a systematic literature search in the databases Pubmed and Wiley Online Library was conducted. A panel of experts subsequently evaluated the FAQ drafts, and a consensus was reached in case of conflicting results. Thereafter, the FAQs were evaluated by physicians and veterinarians of the PHS.

RESULTS

Nine FAQs were generated in total. In addition to a survey of the current state of research, recommendations were made for private dealing with non-medical contact with MDR at the interface of human and veterinary medicine. The recommendations depended on the respective setting and the type of animal contact. Different recommendations were given for the handling of MDR in pets, farm animals, animals in communal facilities and animals used for animal-assisted therapies. The most important measure against the spread of MDR between humans and animals proved to be regular and careful handwashing.

CONCLUSION

Mixed methods were used to ensure the quality of the FAQ. Limitations were found in the literature search. Not all submitted questions could be answered with the available literature. In the future, the FAQ should be continuously updated and extended.

Multiresistant Gram-Negative Pathogens—A Zoonotic Problem

BACKGROUND

Extended-spectrum-β-lactamase-producing, carbapenemase-producing, and colistin-resistant Enterobacteriaceae (ESBL-E, CPE, and Col-E) are multiresistant pathogens that are increasingly being encountered in both human and veterinary medicine. In this review, we discuss the frequency, sources, and significance of the zoonotic transmission of these pathogens between animals and human beings.

METHODS

This review is based on pertinent publications retrieved by a selective literature search. Findings for Germany are presented in the global context.

RESULTS

ESBL-E are common in Germany in both animals and human beings, with a 6-10% colonization rate in the general human population. A major source of ESBL-E is human-tohuman transmission, partly through travel. Some colonizations are of zoonotic origin (i.e., brought about by contact with animals or animal-derived food products); in the Netherlands, more than 20% of cases are thought to be of this type. CPE infections, on the other hand, are rare in Germany in both animals and human beings. Their main source in human beings is nosocomial transmission. Col-E, which bear mcr resistance genes, have been described in Germany mainly in food-producing animals and their meat. No representative data are available on Col-E in human beings in Germany; in Europe, the prevalence of colonization is less than 2%, with long-distance travel as a risk factor. The relevance of animals as a source of Col-E for human beings is not yet entirely clear.

CONCLUSION

Livestock farming and animal contact affect human colonization with the multiresistant Gram-negative pathogens CPE, ESBL-E and Col-E to differing extents. Improved prevention will require the joint efforts of human and veterinary medicine.

Antimicrobial Resistance Profiles of Coagulase-Negative Staphylococci in Community-Based Healthy Individuals in Germany

Coagulase-negative staphylococci (CoNS) are common opportunistic pathogens, but also ubiquitous human and animal commensals. Infection-associated CoNS from healthcare environments are typically characterized by pronounced antimicrobial resistance (AMR) including both methicillin- and multidrug-resistant isolates. Less is known about AMR patterns of CoNS colonizing the general population. Here we report on AMR in commensal CoNS recovered from 117 non-hospitalized volunteers in a region of Germany with a high livestock density. Among the 69 individuals colonized with CoNS, 29 had reported contacts to either companion or farm animals. CoNS were selectively cultivated from nasal swabs, followed by species definition by 16S rDNA sequencing and routine antibiotic susceptibility testing. Isolates displaying phenotypic AMR were further tested by PCR for presence of selected AMR genes. A total of 127 CoNS were isolated and Staphylococcus epidermidis (75%) was the most common CoNS species identified. Nine isolates (7%) were methicillin-resistant (MR) and carried the mecA gene, with seven individuals (10%) being colonized with at least one MR-CoNS isolate. While resistance against gentamicin, phenicols and spectinomycin was rare, high resistance rates were found against tetracycline (39%), erythromycin (33%) and fusidic acid (24%). In the majority of isolates, phenotypic resistance could be associated with corresponding AMR gene detection. Multidrug-resistance (MDR) was observed in 23% (29/127) of the isolates, with 33% (23/69) of the individuals being colonized with MDR-CoNS. The combined data suggest that MR- and MDR-CoNS are present in the community, with previous animal contact not significantly influencing the risk of becoming colonized with such isolates.

Variability of antibiograms: how often do changes in the antimicrobial susceptibility pattern occur in isolates from one patient?

OBJECTIVES

Many laboratories do not perform antimicrobial susceptibility testing (AST) for all consecutive isolates of the same species from one patient. The objective of this study was to assess how often changes in antimicrobial susceptibility patterns (cASP) occur in such isolates.

METHODS

AST was performed for all isolates of defined species obtained from clinical routine (2015-2018) without restrictions for consecutive or sequential isolates of one patient. Occurrence of cASP and time between the first sampling date and first cASP were determined by combining antibiograms from all specimens and after stratification into species and specimens.

RESULTS

A total of 35 473 AST results were included (range 2-71 per case). Combining pathogens and specimens, 1991 cASP occurred in 1269/8502 (14.9%) of all cases after a median time until cASP of 5 days (range 0-364). Of these, 628/1991 (31.5%) occurred on the day of first sampling (predominantly due to phenotypic variants in the same specimen). Excluding isolates with differing AST pattern on the first day of sampling, the median time until cASP was 12 days (range 1-364). Stratification into species and specimen revealed a large variance of the median time until cASP (e.g. in Escherichia coli: 5 days; range 1-48 for blood cultures or 16 days; 1-364 for urine).

DISCUSSION

Using routine microbiological data in a large tertiary hospital, cASP occurs occasionally. The time to perform subsequent AST to detect cASP depends on the species and type of specimen. Other studies are needed to evaluate whether ideal time intervals applicable beyond local settings can be defined.

A comparison of two multiplex-PCR assays for the diagnosis of traveller's diarrhoea

Background

Numerous multiplex-PCR assays are now available in routine diagnostics but their clinical value is controversial if a clear association between clinical symptoms and the detection of a particular pathogen is missing. The objective of this work was to evaluate a multiplex-PCR assay for the diagnosis of traveller’s diarrhoea (TD) in a case-control study and to assess the concordance with the BioFire® FilmArray® Gastrointestinal Panel.

Methods

Stool samples from cases (n = 61) and controls (n = 30) were collected during travel and analysed by the GI-EB Screening assay (Seegene) in a case-control study. The concordance with the BioFire® FilmArray® Gastrointestinal Panel was expressed as the proportion of participants in which both tests agreed in the category “detected” and “not detected”.

Results

None of the test-target organisms (Campylobacter spp., Clostridioides difficile toxin A/B, Salmonella spp., Shigella spp./enteroinvasive Escherichia coli, E. coli O157, Shiga toxin-producing E. coli, Yersinia enterocolitica) was significantly associated with TD GI-EB Screening assay. The GI-EB Screening assay had an agreement with the BioFire® FilmArray® of 86.8–100%.

Conclusion

The selection of test-target organisms included in the GI-EB Screening assay appears inappropriate for the diagnostic work-up of TD as none of the detected pathogens was associated with TD. The GI-EB Screening assay had a good concordance with BioFire® FilmArray®.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05885-3.

Single Blinded Study on the Feasibility of Decontaminating LA-MRSA in Pig Compartments under Routine Conditions

： In countries with intensive pig husbandry in stables, the prevalence of livestock-associated (LA) methicillin-resistant Staphylococcus aureus (MRSA) on such farms has remained high in the last few years or has also further increased. Simple measures to reduce the LA-MRSA among pigs have not yet been successfully implemented. Earlier publications showed a decontamination of LA-MRSA was only possible with great effort. The aim of this study is to determine the suitability of routine cleaning and disinfection (C&D) for adequate LA-MRSA decontamination. For this purpose, at least 115 locations in a piglet-rearing compartment were examined before and after cleaning and disinfection. The sample locations were stratified according to accessibility for pigs and the difficulty of cleaning. The cleaning work was carried out routinely by farm employees, who were not informed about the sampling (single blinded). While before cleaning and disinfection, 85% of the samples from the surfaces were LA-MRSA positive, while only 2% were positive thereafter. All LA-MRSA-positive samples after cleaning and disinfection were outside the animal area. Air samples also showed no LA-MRSA after cleaning and disinfection. Conclusion: In well-managed livestock farms, decontamination of the LA-MRSA barn is quite possible; after C&D no LA-MRSA was detectable at animal height.

Heterogeneity of antimicrobial susceptibility testing results for sulfamethoxazole/trimethoprim obtained from clinical equine Staphylococcus aureus isolates using different methods

Based on antimicrobial susceptibility testing (AST), correct classifications as susceptible, intermediate or resistant are challenging for some antimicrobial agent-bacterial species combinations. In this study, we investigated 19 equine Staphylococcus aureus isolates for their susceptibility to the combination sulfamethoxazole/trimethoprim (SXT) by using broth microdilution (BMD), agar disk diffusion (DD) and automated test systems. To elucidate the presence of the corresponding genetic resistance properties among the isolates, whole genome sequence analysis was performed and the genomes were screened for trimethoprim (TMP) resistance genes and mutations in the deduced FolP amino acid (aa) sequences, known to confer sulfonamide resistance. To check for hetero-resistance, zone diameters in DD were screened after 18 and 42 h of incubation. All 19 isolates harboured one of the TMP resistance genes dfrG or dfrS1. Three isolates had an aa exchange in their FolP aa sequence (F17L), which has previously been described to result in sulfonamide resistance. These isolates were classified as SXT-resistant by all methods. The remaining 16 isolates were classified as SXT-susceptible or -intermediate (BMD and/or DD) or SXT-resistant (mainly automated test systems). None of the isolates had relevant aa variations in their FolP aa sequences. All 19 isolates showed slight growth within their SXT inhibition zone by DD, pointing towards hetero-resistance. Overall, automated test systems classified isolates lacking genetic resistance determinants more frequently as SXT-resistant than DD and BMD. Therefore, further studies are needed to define a reliable method for SXT susceptibility testing.

Cross-border comparison of antimicrobial resistance (AMR) and AMR prevention measures: the healthcare workers' perspective

Background

Cross-border healthcare may promote the spread of multidrug-resistant microorganisms (MDRO) and is challenging due to heterogeneous antimicrobial resistance (AMR) prevention measures (APM). The aim of this article is to compare healthcare workers (HCW) from Germany (DE) and The Netherlands (NL) on how they perceive and experience AMR and APM, which is important for safe patient exchange and effective cross-border APM cooperation.

Methods

A survey was conducted amongst HCW (n = 574) in hospitals in DE (n = 305) and NL (n = 269), using an online self-administered survey between June 2017 and July 2018. Mann-Whitney U tests were used to analyse differences between answers of German and Dutch physicians (n = 177) and German and Dutch nurses (n = 397) on 5-point Likert Items and Scales.

Results

Similarities between DE and NL were a high awareness about the AMR problem and the perception that the possibility to cope with AMR is limited (30% respondents perceive their contribution to limit AMR as insufficient). Especially Dutch nurses scored significantly lower than German nurses on their contribution to limit AMR (means 2.6 vs. 3.1, p ≤ 0.001). German HCW were more optimistic about their potential role in coping with AMR (p ≤ 0.001), and scored higher on feeling sufficiently equipped to perform APM (p ≤ 0.003), although the mean scores did not differ much between German and Dutch respondents.

Conclusions

Although both German and Dutch HCW are aware of the AMR problem, they should be more empowered to contribute to limiting AMR through APM (i.e. screening diagnostics, infection diagnosis, treatment and infection control) in their daily working routines. The observed differences reflect differences in local, national and cross-border structures, and differences in needs of HCW, that need to be considered for safe patient exchange and effective cross-border APM.

Zoonotic multidrug-resistant microorganisms among non-hospitalized horses from Germany

Colonization with multidrug-resistant organisms (MDROs) belonging to the genus Staphylococcus and the order Enterobacterales poses a particular threat to populations at risk. While previous studies focused on MDRO carriage among livestock or companion animals, respective epidemiological data on the general equine population are limited. Here, carriage of methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (ESBL-E) in non-hospitalized horses living on private farms in the rural area in Northwest Germany was assessed. Intranasal and perianal swab samples were cultured on solid chromogenic media directly and after enrichment in tryptic soy broth, respectively. S. aureus isolates were spa-typed, MRSA and ESBL-E were further classified by phenotypic and molecular methods. Additionally, a subgroup of the first 20 samples was used to isolate and characterize staphylococci other than S. aureus. Among 223 horses, fifteen (6.8%) carried S. aureus. Two isolates were identified as MRSA (0.9% of all horses, mecA-positive) and classified as spa types t011 and t6867, both known as members of the livestock-associated MRSA MLST clonal complex 398. Nine horses (4.0%) were colonized by ESBL-Escherichia coli positive for bla_CTX-M and/or bla_TEM. ESBL-E carriage was associated with prior antibiotic treatment (4/31 vs. 5/183; p = 0.0362) and veterinary examinations (4/31 vs. 5/183; p = 0.0362). In the subgroup, nine different staphylococcal species other than S. aureus were found. The high prevalence of ESBL-E. coli in non-hospitalized horses underlines the necessity to raise awareness for strain dissemination across different hosts in order to do justice to the “One Health” concept.

•

The prevalence of equine ESBL-E carriage is 4.0%.

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0.9% of horses carry MRSA.

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Risk factors for ESBL-E carriage: antibiotic treatment and veterinary examinations.

Changing epidemiology of meticillin-resistant Staphylococcus aureus in 42 hospitals in the Dutch-German border region, 2012 to 2016: results of the search-and-follow-policy

IntroductionMeticillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections.AimWe describe MRSA colonisation/infection and bacteraemia rate trends in Dutch-German border region hospitals (NL-DE-BRH) in 2012-16.MethodsAll 42 NL-DE BRH (8 NL-BRH, 34 DE-BRH) within the cross-border network EurSafety Health-net provided surveillance data (on average ca 620,000 annual hospital admissions, of these 68.0% in Germany). Guidelines defining risk for MRSA colonisation/infection were reviewed. MRSA-related parameters and healthcare utilisation indicators were derived. Medians over the study period were compared between NL- and DE-BRH.ResultsMeasures for MRSA cases were similar in both countries, however defining patients at risk for MRSA differed. The rate of nasopharyngeal MRSA screening swabs was 14 times higher in DE-BRH than in NL-BRH (42.3 vs 3.0/100 inpatients; p < 0.0001). The MRSA incidence was over seven times higher in DE-BRH than in NL-BRH (1.04 vs 0.14/100 inpatients; p < 0.0001). The nosocomial MRSA incidence-density was higher in DE-BRH than in NL-BRH (0.09 vs 0.03/1,000 patient days; p = 0.0002) and decreased significantly in DE-BRH (p = 0.0184) during the study. The rate of MRSA isolates from blood per 100,000 patient days was almost six times higher in DE-BRH than in NL-BRH (1.55 vs 0.26; p = 0.0041). The patients had longer hospital stays in DE-BRH than in NL-BRH (6.8 vs 4.9; p < 0.0001). DE-BRH catchment area inhabitants appeared to be more frequently hospitalised than their Dutch counterparts.ConclusionsOngoing IPC efforts allowed MRSA reduction in DE-BRH. Besides IPC, other local factors, including healthcare systems, could influence MRSA epidemiology.

Zoonotic multidrug-resistant microorganisms among small companion animals in Germany

Antimicrobial multidrug-resistant microorganisms (MDRO) can be transmitted between companion animals and their human owners. Aim of this study was to determine the prevalence of extended spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) and Staphylococcus aureus including methicillin-resistant S. aureus (MRSA) in different companion animal species. Dogs (n = 192), cats (n = 74), and rabbits (n = 17), treated in a veterinary practice and hospital or living in an animal shelter and private households, were sampled. All facilities were located in a region characterized by a high density of pig production. Nasal, buccal and perianal swabs were enriched and cultured on solid chromogenic selective media. A subgroup of 20 animals (13 dogs, 3 cats, 4 rabbits) was analyzed for the presence of staphylococci other than S. aureus. Amongst all animals (n = 283), twenty dogs (10.4%) and six cats (8.1%) carried S. aureus. MRSA was found in five dogs (2.6%) and two cats (2.7%). Isolates were of spa types t011, t034, t108 (all mecA-positive, ST398), and t843 (mecC-positive, ST130), typical for livestock-associated (LA)-MRSA. Except for one dog, MRSA-positive animals did not have direct contact to husbandry. ESBL-Escherichia coli (bla_CTX-M/bla_TEM/bla_SHV genes) were present in seven dogs (3.6%), one cat (1.4%) possessed a cefotaxime-resistant Citrobacter freundii isolate (bla_TEM/bla_CMY-2 genes). MDRO carriage was associated with animals from veterinary medical settings (p<0.05). One dog and one rabbit carried methicillin-resistant coagulase-negative staphylococci. The exclusive occurrence of MRSA lineages typically described for livestock stresses the impact of MDRO strain dissemination across species barriers in regional settings. Presence of ESBL-E and LA-MRSA among pets and probable dissemination in clinical settings support the necessity of a “One Health” approach to address the potential threats due to MDRO-carrying companion animals.

SuperPolymyxin™ Medium for the Screening of Colistin-Resistant Gram-Negative Bacteria in Stool Samples

Colistin is one of the last resort antimicrobials for the treatment of infections caused by multidrug-resistant Gram-negative bacteria. After the emergence of transferable colistin resistance genes (mcr-1–5), a reliable culture-based screening method to detect colonization with colistin-resistant Gram-negative bacteria (CRGN) is needed. The objective of this study was to test the performance of SuperPolymyxin™ medium to screen for CRGN in stool samples and to compare different methods for the confirmation of colistin resistance (e.g., Etest®, broth microdilution [BMD], and the Rapid Polymyxin™ NP test). Colonization with CRGN was analyzed in a prospective cohort study among travelers. Stool samples (Fecal Transwab^TM) taken before, during and after travel were cultured on SuperPolymyxin™ agar. Every phenotypically different colony was subcultured for species identification using MALDI-TOF mass spectrometry. Susceptibility to colistin was tested using Etest® and confirmed by BMD and the Rapid Polymyxin™ NP test. In total, 128 participants provided 1,495 stool samples. After culture on SuperPolymyxin™ medium (37°C, 24–48 h), 1,851 phenotypically different colonies were isolated. Isolates belonging to intrinsically colistin-resistant genera (e.g., Morganella, Providencia, Proteus) or Stenotrophomonas maltophilia were excluded from further analysis (n = 421). Among the remaining 1,430 isolates, colistin resistance was confirmed in 279 by Etest® (19.5%) and 218 by BMD (15.3%). The Rapid Polymyxin™ NP test was compared with BMD (reference) to detect colistin resistance (specificity: 88.6%, sensitivity 71.1%). SuperPolymyxin™ medium is suitable to screen for fecal colonization with CRGN. The high proportion of colistin-susceptible isolates growing on SuperPolymyxin™ medium caused a high workload. The confirmation of CRGN with the Rapid Polymyxin™ NP Test could be a less labor-intensive alternative to BMD.

[Multidrug-resistant bacteria in animals and humans]

BACKGROUND

The increasing burden of antimicrobial-resistant bacteria causes morbidity and mortality, especially among patients affected by healthcare-associated infections. Limited treatment options challenge clinicians in both human and veterinary medicine.

OBJECTIVES

To summarize current evidence for the occurrence of antimicrobial-resistant bacteria and their zoonotic transmission between humans and animals with a focus on data from Germany.

MATERIALS AND METHODS

Review of scientific literature and publications from German national public health institutions.

RESULTS AND CONCLUSIONS

Methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β‑lactamase (ESBL) producing Enterobacteriaceae are frequently transmitted between animals and humans. The rates of asymptomatic carriage are increased among persons with livestock contact compared with the general population. The occurrence of carbapenemase-producing Enterobacteriaceae has been documented on German pig and chicken farms, but investigations into their prevalence and zoonotic importance are pending. Colistin is frequently used in veterinary medicine to treat diarrhoea and causes selection pressure for colistin-resistant Gram-negative bacteria harbouring mcr genes. Vancomycin-resistant enterococci (VRE), oxazolidinone-resistant Gram-positive bacteria and multiresistant staphylococci are further antimicrobial-resistant microorganisms, which might have a zoonotic potential. Besides human healthcare and livestock, the problem of antimicrobial-resistant bacteria also affects companion animals (e. g. dogs, cats and horses), wildlife and the environment, which underlines the need to prevent antimicrobial resistance in a One Health approach.

Carbapenem-resistant Enterobacteriaceae in wildlife, food-producing, and companion animals: a systematic review

OBJECTIVES

The spread of carbapenem-resistant Enterobacteriaceae (CRE) in healthcare settings challenges clinicians worldwide. However, little is known about dissemination of CRE in livestock, food, and companion animals and potential transmission to humans.

METHODS

We performed a systematic review of all studies published in the PubMed database between 1980 and 2017 and included those reporting the occurrence of CRE in samples from food-producing and companion animals, wildlife, and exposed humans. The primary outcome was the occurrence of CRE in samples from these animals; secondary outcomes included the prevalence of CRE, carbapenemase types, CRE genotypes, and antimicrobial susceptibilities.

RESULTS

We identified 68 articles describing CRE among pigs, poultry, cattle, seafood, dogs, cats, horses, pet birds, swallows, wild boars, wild stork, gulls, and black kites in Africa, America, Asia, Australia, and Europe. The following carbapenemases have been detected (predominantly affecting the genera Escherichia and Klebsiella): VIM, KPC, NDM, OXA, and IMP. Two studies found that 33-67% of exposed humans on poultry farms carried carbapenemase-producing CRE closely related to isolates from the farm environment. Twenty-seven studies selectively screened samples for CRE and found a prevalence of <1% among livestock and companion animals in Europe, 2-26% in Africa, and 1-15% in Asia. Wildlife (gulls) in Australia and Europe carried CRE in 16-19%.

CONCLUSIONS

The occurrence of CRE in livestock, seafood, wildlife, pets, and directly exposed humans poses a risk for public health. Prospective prevalence studies using molecular and cultural microbiological methods are needed to better define the scope and transmission of CRE.

Defining Multidrug Resistance of Gram-Negative Bacteria in the Dutch-German Border Region-Impact of National Guidelines

Preventing the spread of multidrug-resistant Gram-negative bacteria (MDRGNB) is a public health priority. However, the definition of MDRGNB applied for planning infection prevention measures such as barrier precautions differs depending on national guidelines. This is particularly relevant in the Dutch–German border region, where patients are transferred between healthcare facilities located in the two different countries, because clinicians and infection control personnel must understand antibiograms indicating MDRGNB from both sides of the border and using both national guidelines. This retrospective study aimed to compare antibiograms of Gram-negative bacteria and classify them using the Dutch and German national standards for MDRGNB definition. A total of 31,787 antibiograms from six Dutch and four German hospitals were classified. Overall, 73.7% were no MDRGNB according to both guidelines. According to the Dutch and German guideline, 7772/31,787 (24.5%) and 4586/31,787 (12.9%) were MDRGNB, respectively (p < 0.0001). Major divergent classifications were observed for extended-spectrum β-lactamase (ESBL) -producing Enterobacteriaceae, non-carbapenemase-producing carbapenem-resistant Enterobacteriaceae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. The observed differences show that medical staff must carefully check previous diagnostic findings when patients are transferred across the Dutch–German border, as it cannot be assumed that MDRGNB requiring special hygiene precautions are marked in the transferred antibiograms in accordance with both national guidelines.

Increase of zinc resistance in German human derived livestock-associated MRSA between 2000 and 2014

PROBLEM ADDRESSED

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA), particularly of the clonal complex (CC) 398, emerged as zoonotic pathogens predominantly among humans with direct or indirect livestock contact, but also in healthcare settings. The factors contributing to the success of LA-MRSA are only poorly understood.

OBJECTIVE

During the past years, the use of heavy metal compounds as feed-supplements was found to influence the co-selection of LA-MRSA in pig herds. This study aimed to determine the prevalence of zinc resistance among MRSA CC398 isolated from patients of a German university hospital located in a pig farming-dense area.

METHODS AND APPROACH

In comparison to concurrent healthcare-associated MRSA (HA-MRSA), LA-MRSA CC398 comprising isolates from their first appearance in 2000 to recent isolates from 2014 were included.

RESULTS

Among MRSA CC398, the overall resistance rate towards zinc chloride was 57% compared to only 3% among concurrently isolated HA-MRSA. Zinc resistance correlated with the presence of the czrC gene in 100% of the MRSA CC398 and in 67% of the HA-MRSA.

CONCLUSIONS

The zinc resistance rate in MRSA CC398 significantly increased from 2009 to 2014 with a maximum in 2014. Alarmingly, zinc resistance has become a frequent phenotype of human LA-MRSA in Germany potentially facilitating co-selection of antibiotic resistance genes.

Epidemiology of Extended-Spectrum β-Lactamase-Producing E. coli and Vancomycin-Resistant Enterococci in the Northern Dutch-German Cross-Border Region

Objectives: To reveal the prevalence and epidemiology of extended-spectrum β-lactamase (ESBL)- and/or plasmid AmpC (pAmpC)- and carbapenemase (CP) producing Enterobacteriaceae and vancomycin-resistant enterococci (VRE) across the Northern Dutch–German border region.

Methods: A point-prevalence study on ESBL/pAmpC/CP producing Enterobacteriaceae and VRE was carried out in hospitalized patients in the Northern Netherlands (n = 445, 2012–2013) and Germany (n = 242, 2012). Healthy individuals from the Dutch community (n = 400, 2010–2012) were also screened. In addition, a genome-wide gene-by-gene approach was applied to study the epidemiology of ESBL-Escherichia coli and VRE.

Results: A total of 34 isolates from 27 patients (6.1%) admitted to Dutch hospitals were ESBL/pAmpC positive and 29 ESBL-E. coli, three pAmpC-E. coli, one ESBL-Enterobacter cloacae, and one pAmpC-Proteus mirabilis were found. In the German hospital, 18 isolates (16 E. coli and 2 Klebsiella pneumoniae) from 17 patients (7.7%) were ESBL positive. In isolates from the hospitalized patients CTX-M-15 was the most frequently detected ESBL-gene. In the Dutch community, 11 individuals (2.75%) were ESBL/pAmpC positive: 10 ESBL-E. coli (CTX-M-1 being the most prevalent gene) and one pAmpC E. coli. Six Dutch (1.3%) and four German (3.9%) hospitalized patients were colonized with VRE. Genetic relatedness by core genome multi-locus sequence typing (cgMLST) was found between two ESBL-E. coli isolates from Dutch and German cross-border hospitals and between VRE isolates from different hospitals within the same region.

Conclusion: The prevalence of ESBL/pAmpC-Enterobacteriaceae was similar in hospitalized patients across the Dutch–German border region, whereas VRE prevalence was slightly higher on the German side. The overall prevalence of the studied pathogens was lower in the community than in hospitals in the Northern Netherlands. Cross-border transmission of ESBL-E. coli and VRE seems unlikely based on cgMLST analysis, however continuous monitoring is necessary to control their spread and stay informed about their epidemiology.

Implementation of short incubation MALDI-TOF MS identification from positive blood cultures in routine diagnostics and effects on empiric antimicrobial therapy

Background

Results of blood culture (BC) diagnostics should be swiftly available to guide treatment of critically ill patients. Conventional BC diagnostics usually performs species identification of microorganisms from mature solid medium colonies. Species identification might be speed up by using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) of biomass from shortly incubated solid media.

Methods

This single-center analysis compared the applicability of MALDI-TOF-based species identification from shortly incubated cultures in laboratory routine vs. conventional diagnostics and assessed its effects of on empiric antibiotic therapy.

Results

Median time between detection of BCs as “positive” by incubators and further processing (e.g. microscopy) was 6 h 21 min. Median time between microscopy and result reporting to the ward was 15 min. Including 193 BCs, MALDI-TOF from shortly incubated biomass resulted in significantly faster (p > 0.001) species identification. Species results became available for clinicians after a median of 188 min (231 min for Gram-positive bacteria, 151 min for Gram-negative bacteria) compared to 909 min (n = 192 BCs) when conventional diagnostics was used. For 152/179 bacteremia episodes (85%) empiric antibiotic therapy had already been started when the microscopy result was reported to the ward; microscopy led to changes of therapies in 14/179 (8%). In contrast, reporting the bacterial species (without antibiogram) resulted in therapeutic adjustments in 36/179 (20%). Evaluating these changes revealed improved therapies in 26/36 cases (72%).

Conclusions

Species identification by MALDI-TOF MS from shortly incubated subcultures resulted in adjustments of empiric antibiotic therapies and might improve the clinical outcome of septic patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13756-017-0173-4) contains supplementary material, which is available to authorized users.

MRSA Prevalence and Associated Risk Factors among Health-Care Workers in Non-outbreak Situations in the Dutch-German EUREGIO

Preventing the spread of methicillin-resistant Staphylococcus aureus (MRSA) in healthcare facilities is a major infection control target. However, only a few studies have assessed the potential role of healthcare workers (HCWs) for MRSA dissemination. To investigate the MRSA prevalence and the risk factors for MRSA colonization among HCWs, nasopharyngeal swabs were taken between June 2010 and January 2011 from 726 employees from nine acute care hospitals with different care levels within the German part of a Dutch-German border region (EUREGIO). The isolated MRSA strains were investigated using spa typing. The overall MRSA prevalence among HCWs in a non-outbreak situation was 4.6% (33 of 726), and was higher in nurses (5.6%, 29 of 514) than in physicians (1.2%, 1 of 83). Possible risk factors associated with MRSA colonization were a known history of MRSA carriage and the presence of acne. Intensive contact with patients may facilitate MRSA transmission between patients and HCWs. Furthermore, an accumulation of risk factors was accompanied by an increased MRSA prevalence in HCW.

Evaluation of an Automated System for Reading and Interpreting Disk Diffusion Antimicrobial Susceptibility Testing of Fastidious Bacteria

Results of disk diffusion antimicrobial susceptibility testing depend on individual visual reading of inhibition zone diameters. Therefore, automated reading using camera systems might represent a useful tool for standardization. In this study, the ADAGIO automated system (Bio-Rad) was evaluated for reading disk diffusion tests of fastidious bacteria. 144 clinical isolates (68 β-haemolytic streptococci, 28 Streptococcus pneumoniae, 18 viridans group streptococci, 13 Haemophilus influenzae, 7 Moraxella catarrhalis, and 10 Campylobacter jejuni) were tested on Mueller-Hinton agar supplemented with 5% defibrinated horse blood and 20 mg/L β-NAD (MH-F, Oxoid) according to EUCAST. Plates were read manually with a ruler and automatically using the ADAGIO system. Inhibition zone diameters, indicated by the automated system, were visually controlled and adjusted, if necessary. Among 1548 isolate-antibiotic combinations, comparison of automated vs. manual reading yielded categorical agreement (CA) without visual adjustment of the automatically determined zone diameters in 81.4%. In 20% (309 of 1548) of tests it was deemed necessary to adjust the automatically determined zone diameter after visual control. After adjustment, CA was 94.8%; very major errors (false susceptible interpretation), major errors (false resistant interpretation) and minor errors (false categorization involving intermediate result), calculated according to the ISO 20776-2 guideline, accounted to 13.7% (13 of 95 resistant results), 3.3% (47 of 1424 susceptible results) and 1.4% (21 of 1548 total results), respectively, compared to manual reading. The ADAGIO system allowed for automated reading of disk diffusion testing in fastidious bacteria and, after visual validation of the automated results, yielded good categorical agreement with manual reading.

The pathogenicity and host adaptation of livestock-associated MRSA CC398

The presence of methicillin-resistant Staphylococcus aureus (MRSA) CC398 in livestock and their transmission to humans followed by their introduction into hospitals led to a significant burden for the human healthcare system, especially in regions with a high density of livestock breeding. The CC398 lineage made two host changes in its evolutionary history: From humans to pigs and other livestock-associated animals and back to the human host. These adaptation processes are mirrored by changes of the equipment with virulence factors necessary for successful host change. Here, we consider these factors and their special role during human colonization and infection. Host adaptation of S. aureus CC398 is accompanied by genetic changes that are mainly driven by exchanges of mobile genetic elements. So far, it is not clear, which virulence or adhesion factors are important for S. aureus CC398 in host interaction. Among human and animal-derived MRSA CC398 virulence factors, e.g. (entero-) toxins, were rarely found. Overall, this review provides a comprehensive overview on the emerging S. aureus lineage CC398 by summarizing current knowledge from microbiological, molecular and cellular interaction studies in relation to clinical and epidemiological perspectives.

Cross-border comparison of antibiotic prescriptions among children and adolescents between the north of the Netherlands and the north-west of Germany

Background

Antibiotic resistance is a worldwide problem and inappropriate prescriptions are a cause. Especially among children, prescriptions tend to be high. It is unclear how they differ in bordering regions. This study therefore examined the antibiotic prescription prevalence among children in primary care between northern Netherlands and north-west of Germany.

Methods

Two datasets were used: The Dutch (IADB) comprises representative data of pharmacists in North Netherland and the German (BARMER GEK) includes nationwide health insurance data. Both were filtered using postal codes to define two comparable bordering regions with patients under 18 years for 2010.

Results

The proportion of primary care patients receiving at least one antibiotic was lower in northern Netherlands (29.8 %; 95 % confidence interval [95 % CI]: 29.3–30.3), compared to north-west Germany (38.9 %; 95 % CI: 38.2–39.6). Within the respective countries, there were variations ranging from 27.0 to 44.1 % between different areas. Most profound was the difference in second-generation cephalosporins: for German children 25 % of the total prescriptions, while for Dutch children it was less than 0.1 %.

Conclusions

This study is the first to compare outpatient antibiotic prescriptions among children in primary care practices in bordering regions of two countries. Large differences were seen within and between the countries, with overall higher prescription prevalence in Germany. Considering increasing cross-border healthcare, these comparisons are highly valuable and help act upon antibiotic resistance in the first line of care in an international approach.

In the centre of an epidemic: Fifteen years of LA-MRSA CC398 at the University Hospital Münster

Ten years after initial publications on livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in 2005, we report on the course of the LA-MRSA CC398 epidemic among patients of the University Hospital Münster. This tertiary care facility is located in the Dutch-German border region (EUREGIO), which is characterized by a high density of livestock production and is hence a hotspot for the occurrence of LA-MRSA CC398. Taking advantage of the unique opportunity to track the emergence and spread of MRSA CC398 among humans from the very beginning of the epidemic until today, a total of 6555 non-duplicate MRSA isolates from all screenings and clinical specimens cultivated within the period from 2000 to 2014 were included in the analysis. Retrospectively, the first MRSA CC398 isolate (spa type t034) was obtained from a screening specimen of a patient in 2000, which represents one of the first human-associated LA-MRSA CC398 isolates reported in Europe. After sporadic detections between 2000 and 2004, this clonal lineage accounted for 9.6% of all local MRSA in 2005; a proportion which increased to 35% in 2013 and became stable since then. Considering the period from 2000 to 2014, the group of MRSA CC398 isolates comprised a total of 45 different spa types among which t011 (48.3%), t034 (39.3%) and t108 (3.5%) were predominant and so far unreported types were found. Overall, LA-MRSA CC398 emerged rapidly during the past decade, developed enormous sublineage diversity and contributed substantially to the total burden of MRSA colonization and infection at the hospital.

Methicillin-resistant Staphylococcus aureus from infections in horses in Germany are frequent colonizers of veterinarians but rare among MRSA from infections in humans

A total of 272 methicillin-resistant Staphylococcus aureus (MRSA) from equine infections originating from 17 equine hospitals and 39 veterinary practices in Germany as well as 67 isolates from personnel working at equine clinics were subjected to molecular typing. The majority of isolates from horses was attributed to clonal complex (CC) 398 (82.7%). Within CC398, 66% of isolates belonged to a subpopulation (clade) of CC398, which is associated with equine clinics.

MRSA attributed to CC8 (ST254, t009, t036, SCCmecIV; ST8, t064, SCCmecIV) were less frequent (16.5%). Single isolates were attributed to ST1, CC22, ST130, and ST1660. The emergence of MRSA CC22 and ST130 in horses was not reported so far. Nasal MRSA colonization was found in 19.5% of veterinary personnel with occupational exposure to horses. The typing characteristics of these isolates corresponded to isolates from equine infections.

Comparing typing characteristics of equine isolates with those of a substantial number of isolates from human infections typed at the German Reference Center for Staphylococci and Enterococci (2006–2014; n = 10864) yielded that the proportion of isolates exhibiting characteristics of MRSA from equine medicine is very low (< 0.5%). As this low proportion was also found among MRSA originating from nasal screenings of human carriers not suffering from a staphylococcal infection (n = 5546) transmission of MRSA from equine clinics to the community seems to be rare so far.

Persistence of nasal colonization with human pathogenic bacteria and associated antimicrobial resistance in the German general population

The nares represent an important bacterial reservoir for endogenous infections. This study aimed to assess the prevalence of nasal colonization by different important pathogens, the associated antimicrobial susceptibility and risk factors. We performed a prospective cohort study among 1878 nonhospitalized volunteers recruited from the general population in Germany. Participants provided nasal swabs at three time points (each separated by 4–6 months). Staphylococcus aureus, Enterobacteriaceae and important nonfermenters were cultured and subjected to susceptibility testing. Factors potentially influencing bacterial colonization patterns were assessed. The overall prevalence of S. aureus, Enterobacteriaceae and nonfermenters was 41.0, 33.4 and 3.7%, respectively. Thirteen participants (0.7%) were colonized with methicillin-resistant S. aureus. Enterobacteriaceae were mostly (>99%) susceptible against ciprofloxacin and carbapenems (100%). Extended-spectrum β-lactamase–producing isolates were not detected among Klebsiella oxytoca, Klebsiella pneumoniae and Escherichia coli. Several lifestyle- and health-related factors (e.g. household size, travel, livestock density of the residential area or occupational livestock contact, atopic dermatitis, antidepressant or anti-infective drugs) were associated with colonization by different microorganisms. This study unexpectedly demonstrated high nasal colonization rates with Enterobacteriaceae in the German general population, but rates of antibiotic resistance were low. Methicillin-resistant S. aureus carriage was rare but highly associated with occupational livestock contact.

MRSA Carriage in Community Outpatients: A Cross-Sectional Prevalence Study in a High-Density Livestock Farming Area along the Dutch-German Border

OBJECTIVES

MRSA poses a considerable public health threat to the community. The objectives of this study were to assess the prevalence of MRSA carriage and determine factors that were associated with MRSA carriage among outpatients who had used antibiotics in the previous three months and who lived in a high-density livestock farming area along the Dutch-German border.

METHODS

Cross-sectional prevalence study carried out between November 2011 and June 2012. Nasal swabs and questionnaires were collected in patients (>4 years) who had used antibiotics in the previous three months from twelve Dutch General Practitioners (GPs), seven German GPs and two German outpatient urologists. To assess nasal carriage, swabs were analyzed using selective MRSA agars after broth enrichment. MRSA positive samples were spa typed.

RESULTS

Data were collected from 513 GP outpatients in the Netherlands, 261 GP outpatients in Germany and 200 urologist outpatients in Germany. The overall prevalence of MRSA carriage was 0.8%, 1.1% and 2.0%, respectively. In the GP outpatient populations, the prevalence was similar in both countries (0.8% and 1.1%, respectively, p = 0.879), all spa types were indicative for livestock-associated MRSA (4xt011 in the Netherlands; 2xt034 and t011 in Germany) and being a farmer, living on or near (<5km) to a farm were associated with MRSA carriage. In the urologist outpatient population, the prevalence was higher (2.0%), all spa types were indicative for healthcare-associated MRSA (t068, t032, t003, t10231) and being a farmer, living on or near to a farm were factors not associated with MRSA carriage.

CONCLUSIONS

The prevalence of MRSA carriage in these community outpatient populations along the Dutch-German border was low. There were striking similarities in livestock-associated MRSA carriage and clonal spread in the outpatient populations seeing their GP in both countries. In contrast, urologist outpatients in Germany were colonized with spa types indicative of healthcare-associated MRSA.

MRSA colonization and infection among persons with occupational livestock exposure in Europe: Prevalence, preventive options and evidence

Colonization with livestock-associated Methicillin-resistant Staphylococcusaureus (LA-MRSA) among persons occupationally exposed to pigs, cattle or poultry is very frequent. In Europe, LA-MRSA mostly belong to the clonal lineage CC398. Since colonized persons have an increased risk of developing MRSA infections, defining the burden of work-related infection caused by LA-MRSA CC398 is of interest to exposed personnel, insurance companies and infection control staff. This review summarizes data on the types of occupation-related infections caused by LA-MRSA CC398, the incidence of such infections as well as potential preventive strategies. We identified twelve case reports on infections among livestock-exposed persons. Overall, there is a lack of data describing the incidence of occupation-related infections due to MRSA CC398. Currently, no specific guidance towards the prevention of LA-MRSA CC398 colonization of persons with routine exposure exists. In vitro, MRSA CC398 strains are susceptible (>95%) to mupirocin. Single reports have described effective decolonization of persons carrying LA-MRSA CC398, but long-term success rates are low in case of continuous livestock contact. Overall, the occupational health risk due to LA-MRSA CC398 is not well understood. Currently, prevention of human LA-MRSA CC398 infection is mostly based on the recommendation to perform screening and decolonization therapies prior to elective medical interventions in order to avoid nosocomial infections, but there is no conclusive evidence to perform specific measures aiming to forestall community-acquired infections.

Molecular Typing of Enterobacteriaceae from Pig Holdings in North-Western Germany Reveals Extended- Spectrum and AmpC β-Lactamases Producing but no Carbapenem Resistant Ones

The increase of extended- spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) in humans and in food-producing animals is of public health concern. The latter could contribute to spreading of these bacteria or their resistance genes to humans. Several studies have reported the isolation of third generation cephalosporin resistant bacteria in livestock animals. However, the number of samples and the methodology used differ considerably between studies limiting comparability and prevalence assessment. In the present study, a total of 564 manure and dust samples were collected from 47 pig farms in Northern Germany and analysed to determine the prevalence of ESBL-E. Molecular typing and characterization of resistance genes was performed for all ESBL-E isolates. ESBL-E isolates were found in 55.3% of the farms. ESBL-Escherichia coli was found in 18.8% of the samples, ESBL-Klebsiella pneumoniae in 0.35%. The most prevalent ESBL genes among E. coli were CTX-M-1 like (68.9%), CTX-M-15 like (16%) and CTX-M-9 group (14.2%). In 20% of the latter two, also the OXA-1 like gene was found resulting in a combination of genes typical for isolates from humans. Genetic relation was found between isolates not only from the same, but also from different farms, with multilocus sequence type (ST) 10 being predominant among the E. coli isolates. In conclusion, we showed possible spread of ESBL-E between farms and the presence of resistance genes and STs previously shown to be associated with human isolates. Follow-up studies are required to monitor the extent and pathways of ESBL-E transmission between farms, animals and humans.

[Blood culture diagnostic--challenge or routine standard of care?]

Blood cultures are an essential diagnostic tool to investigate suspected cases of sepsis. However, several studies indicate that (compared with other countries) blood culture diagnostics is only rarely performed in German healthcare facilities. Reasons for this are unknown, but could include clinicians' perception that the turn-around time of results is delayed or that contamination rates are high. Therefore, this article aims to summarize important aspects involved in assuring quality of blood culture diagnostics as well as innovative approaches.

Cross-border comparison of the Dutch and German guidelines on multidrug-resistant Gram-negative microorganisms

BACKGROUND

In all European countries, hospital-acquired infections caused by Gram-negative multidrug-resistant microorganisms (GN-MDRO) are a major health threat, as these pathogens cannot be adequately treated anymore, or the start of effective antibiotic treatment is delayed. The efforts to limit the selection and spread of GN-MDRO remains a problem in cross-border healthcare, as the national guidelines on hygiene standards applicable for patients colonized or infected with GN-MDRO in hospitals are not harmonized between European countries.

METHODS

In order to point out the similarities and differences in the national guidelines of Germany and The Netherlands regarding GN-MDRO, guidelines were compared and an expert workshop was organized by the INTERREG IVa project EurSafety Health-net.

RESULTS

Both guidelines divide the Gram-negative organisms into subgroups based on bacterial species and antibiotic susceptibility patterns in order to define multidrug-resistant variants of these bacteria. However, the Dutch guideline defines that GN-MDRO Enterobacteriaceae requires testing for certain mechanisms causing antibiotic resistance, whereas the German guideline makes use of a newly created classification scheme, based on phenotypic characterization. Besides diagnostic issues, the main difference between the Dutch and German guideline is the divergent evaluation of ESBL-producing Enterobacteriaceae. Special hygiene measures are required for all patients with ESBL-producing Enterobacteriaceae in The Netherlands, whereas the German guideline recommends special precautions only for those cases in which patients are colonized or infected with strains showing co-resistance to ciprofloxacin ("3MRGN").

CONCLUSIONS

The usage of consistent terminology and harmonized diagnostic procedures would improve the possibilities for infection prevention, treatment and patient safety. Prevention of severe non-treatable infections and outbreaks due to MDRO, caused by an increased population seeking medical treatment abroad together with an increased number of highly susceptible individuals demands gathering of regional data, and data comparable between the two sides of the Dutch-German border. The necessity to cooperate multidisciplinary and across borders is required to prevent a post-antibiotic era - in which common infections and minor injuries may lead to death.

State-wide surveillance of antibiotic resistance patterns and spa types of methicillin-resistant Staphylococcus aureus from blood cultures in North Rhine-Westphalia, 2011-2013

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of bacteraemia. We aimed to obtain a complete picture of severe MRSA infections by characterizing all MRSA isolates from bloodstream infections in the largest German federal state (North Rhine-Westphalia, 18 million inhabitants) using S. aureus protein A (spa) sequence-typing and antimicrobial susceptibility testing. MRSA isolates (n = 1952) were collected prospectively (2011-2013) and spa-typed. Among 181 different spa types, t003 (n = 746 isolates; 38.2%) and t032 (n = 594; 30.4%) were predominant. Analysis of the geographical occurrence of spa clonal complexes (spa-CCs) and spa types revealed divergent distribution between federal state districts for spa-CCs 003 (p < 0.001; including t003, p < 0.001 and t264, p < 0.001), 008 (p 0.021), 011 (p 0.002), 032 (p < 0.001; including t022, p 0.014 and t032, p < 0.001) and spa type t2807 (p < 0.001). MICs of antimicrobial substances were tested using broth microdilution. Of all isolates, 96% were resistant to fluoroquinolones, 78% to erythromycin, 70% to clindamycin, 4% to gentamicin, 2% to rifampicin, 0.4% to daptomycin, 0.1% to linezolid and 0% to vancomycin, respectively. Vancomycin MICs of 2 mg/L involved 0.5% of the isolates. In conclusion, the detection of regional molecular clusters added valuable information for epidemiological case tracing and allowed conclusions to be reached on the importance of newly emerging MRSA reservoirs, such as livestock (spa-CC011), for MRSA bacteraemia in some parts of the federal state. Susceptibility testing revealed broad resistance to substances used for oral treatment, but demonstrated that those antibiotics that are mostly applied for treatment of MRSA bacteraemia and important combination partners were highly susceptible.

The risk to import ESBL-producing Enterobacteriaceae and Staphylococcus aureus through chicken meat trade in Gabon

Background

A main export market for chicken meat from industrialized countries is sub-Saharan Africa. We hypothesized that antibiotic resistant bacteria could be exported to developing countries through chicken meat trade. The objective was to investigate the occurrence and molecular types of ESBL-producing Enterobacteriaceae and Staphylococcus aureus in chicken meat in Gabon and to assess their dissemination among humans.

Results

Frozen chicken meat samples imported from industrialized countries to Gabon (n = 151) were screened for ESBL-producing Enterobacteriaceae and S. aureus. Genotypes and resistance genes (SHV, TEM, CTX-M, CMY-2) of isolates from meat were compared with isolates derived from humans.

The contamination rate per chicken part (i. e. leg, wing) with ESBL-producing Escherichia coli (ESBL E. coli, no other ESBL-producing Enterobacteriaceae were found) and S. aureus was 23% and 3%, respectively. The beta-lactamase CTX-M 1 was predominant in ESBL E. coli from meat samples but was not found in isolates from cases of human colonization or infection. S. aureus belonging to spa type t002 (multilocus sequence type ST5) were found both in chicken meat and humans.

Conclusion

There is a risk to import ESBL E. coli to Gabon but molecular differences between isolates from humans and chicken meat argue against a further dissemination. No MRSA isolate was detected in imported chicken meat.

Are cases of Methicillin-resistant Staphylococcus aureus clonal complex (CC) 398 among humans still livestock-associated?

Methicillin-resistant Staphylococcus aureus (MRSA) of clonal complex (CC) 398 are widespread among pigs, cattle and poultry as well as among humans who have contact to these livestock animals. However, there is limited data on livestock-independent dissemination of MRSA CC398 in the general population.

METHODS

In this case-control study MRSA isolates derived (between July 2013 and June 2014) from patients of four hospitals located in a livestock-dense region were S. aureus protein A (spa) typed and risk factors for MRSA acquisition were assessed from patients colonized or infected with MRSA CC398 vs. other MRSA molecular types (MRSA non-CC398).

RESULTS

Of 384 patients, 21% were colonized with MRSA CC398. Contact with livestock (Odds Ratio (OR) 46.03) and residence directly on a pig farm (OR 12.82) were associated with MRSA CC398. Of 55 patients with MRSA CC398, 21 (38%) did not report direct livestock contact. Among the latter we identified several risk factors that could have facilitated indirect transmission, such as living on farms (without being farmer), private contact with known MRSA carriers or previous hospitalization.

DISCUSSION

This study suggests that MRSA CC398 is still mostly disseminated via direct contact to livestock. However, a substantial proportion of patients seem to acquire MRSA CC398 via other pathways.