Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus in Horses, Cats, and Dogs Over a 5-Year Period in France

Methicillin-resistant Staphylococcus spp. investigation in hospitalized horses and contacting personnel in a teaching veterinary hospital

Staphylococci are well-known opportunistic pathogens associated with suppurative diseases in humans and animals. Antimicrobial resistance is an emergent threat to humans and animals worldwide. This study investigated the prevalence of methicillin-resistant Staphylococcus spp. (MRS) in hospitalized horses and contacting personnel (veterinarians and staff), and assessed possible interspecies transmission in a teaching veterinary hospital. Nasal swabs from horses (n = 131) and humans (n = 35) were collected. The microorganisms were identified by traditional biochemical tests and genotypic methods, i.e., PCR, internal transcript spacer PCR (ITS-PCR), and gene sequencing. Staphylococcal species were isolated in 18% (23/131) of the horses, of which 8% (11/131) were S. hyicus, 4 % (5/131) were S. aureus, 4% (5/131) were S. pseudintermedius, and 2% (2/131) were S. schleiferi subsp. coagulans. The mecA gene was detected in an S. pseudintermedius isolate. Staphylococcus spp. was isolated in 40% (14/35) of the human samples, all of which were S. aureus. In four samples of S. aureus, the clonal profile ST398 was identified; among them, a clonal similarity of 98.1% was observed between a horse and a contacting human. This finding supports the need for biosecurity measures to avoid the spread of multidrug-resistant staphylococci in humans and horses.

Resistome-based surveillance identifies ESKAPE pathogens as the predominant gram-negative organisms circulating in veterinary hospitals

Introduction

Healthcare-associated infections (HCAIs) associated with extended-spectrum cephalosporin-resistant gram-negative (ESC-R GN) bacteria are an emerging concern in veterinary hospitals, especially in companion animal intensive care units (ICUs).

Methods

To understand the molecular epidemiology of ESC-R GN isolates in two veterinary hospitals (equine and small animal), a 6-month pilot study was performed during which fecal and environmental samples were obtained twice from selected patients, upon ICU admission and after 48 h of hospitalization. In total, 295 ESC-R GNs were analyzed using the Acuitas Resistome® Test (OpGen, Maryland, US), a PCR-based assay screening for 50 antimicrobial resistance gene families encoding for production of extended-spectrum beta-lactamase (ESBLs), TEM/SHV/OXA or AmpC beta-lactamases and carbapenemases. Combining organism identification and antimicrobial susceptibility data to genotyping results, unique "Acuitas profiles" were generated that can be used for fast typing the isolates and tracking transmission events.

Results

ESKAPE GN pathogens were the most prevalent ESC-R GN isolates circulating in both the small animal and equine hospitals, consisting of Enterobacter cloacae complex (21.7%), Pseudomonas aeruginosa (20%), Klebsiella pneumoniae (15.9%), and Acinetobacter baumannii complex (13.6%) followed by Escherichia coli (12.2%), most harboring a combination of genes encoding for beta-lactamases and ESBLs. Some ESKAPE genotypes showed likely intra-hospital transmission, including E. cloacae (two genotypes, one carrying SHV4, SHV5, and TEM7 and the other TEM1, TEM3, and TEM7 enzymes) in the equine and K. pneumoniae (SHV1, SHV5, and DHA1-positive) in the small animal ICUs, respectively. Furthermore, P. aeruginosa (carrying OXA-50), A. baumannii complex (OXA-51), and E. coli (CTX-M-1) genotypes were isolated across both hospitals, suggesting possible transfer mediated via movement of staff and students. Importantly, isolates carrying transmissible resistance to last-resort antimicrobials (i.e. carbapenems) were identified within the hospital environments, consisting of three environmental Acinetobacter spp. harboring blaOXA - 23 and one clinical E. coli with blaOXA - 48.

Conclusion

We describe the widespread occurrence of ESKAPE gram-negative organisms in veterinary ICU patients and hospital environments. Findings from this project provide baseline data on the epidemiology of ESKAPE pathogens in veterinary settings, which can inform infection control policies to aid in patient management and prevent transmission of nosocomial infections associated with these pathogens.

The Epidemiology of Animal-Associated Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) remains an important etiological factor of human and animal infectious diseases, causing significant economic losses not only in human healthcare but also in the large-scale farming sector. The constantly changing epidemiology of MRSA observed globally affects animal welfare and raises concerns for public health. High MRSA colonization rates in livestock raise questions about the meaning of reservoirs and possible transmission pathways, while the prevalence of MRSA colonization and infection rates among companion animals vary and might affect human health in multiple ways. We present the main findings concerning the circulation of animal-associated MRSA (AA-MRSA) in the environment and factors influencing the direction, mechanisms, and routes of its transmission. Studies have shown it that S. aureus is a multi-host bacterial pathogen; however, its adaptation mechanisms enabling it to colonize and infect both animal and human hosts are still rarely discussed. Finally, we elaborate on the most successful strategies and programs applied limiting the circulation of AA-MRSA among animals and humans. Although MRSA strains colonizing animals rarely infect humans, they undergo host-adaptive evolution enabling them to spread and persist in human populations.

Pet animals as reservoirs for spreading methicillin-resistant Staphylococcus aureus to human health

Methicillin-resistant Staphylococcus aureus (MRSA) is a strain of pathogenic bacteria that is a major problem in the world's health. Due to their frequent interaction with humans, pets are one of the main risk factors for the spread of MRSA. The possibility for zoonotic transmission exists since frequently kept dogs and cats are prone to contract MRSA and act as reservoirs for spreading MRSA. The mouth, nose, and perineum are the primary locations of MRSA colonization, according to the findings of MRSA identification tests conducted on pets. The types of MRSA clones identified in cats and dogs correlated with MRSA clones infecting humans living in the same geographic area. A significant risk factor for the colonization or transmission of MRSA is human-pet contact. An essential step in preventing the spread of MRSA from humans to animals and from animals to humans is to keep hands, clothing, and floor surfaces clean.

Characterisation and prevalence of community-associated MRSA among horses, dogs, cats and their human handlers: a cross-sectional study

Methicillin-resistant Staphylococcus aureus (MRSA) as an infectious organism of public health significance has evolved to a genetically distinct community-acquired MRSA with extended resistance to other than β-lactams. A cross-sectional study was conducted among 149 participants handling 446 animals (240 horses and 206 companion animals). The isolates were characterised as S. aureus and MRSA based on polymerase chain reaction detection of the nuc, mecA and mecC genes and the pvl gene for differentiation as community associated/livestock associated or hospital associated. The isolation rate of S. aureus from the human handlers' samples was 26 (17.4%) and 170 (38.1%) from the animal samples. The prevalence of MRSA among the isolates was 7 (4.7%) from the human handlers and 19 (4.3%) from the animals. Dogs and dog handlers had the highest isolation rates and were more likely to be colonized by S. aureus and MRSA compared with horses, cats and their handlers. The highest prevalence of MRSA was from horses (5.0%) and dog handlers (10.6%). This study has demonstrated a high prevalence of community associated MRSA in apparently healthy animals and their human handlers. This has important implications for antibiotic selection and use as well as infection control measures.

A review of horses as a source of spreading livestock-associated methicillin-resistant Staphylococcus aureus to human health

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) was first discovered in horses in 1989. Since then, LA-MRSA has begun to be considered an important strain of pathogenic bacteria in horses, which can cause LA-MRSA infection and colonization in humans with public health impacts. The anterior nares are the primary site of LA-MRSA colonization in horses, although LA-MRSA colonization may also occur in the gastrointestinal tract in horses. LA-MRSA-infected horses typically exhibit clinical infection or may not exhibit clinical infection. There are two potential risks associated with LA-MRSA colonization in horses: The possibility of disease development in horses infected with LA-MRSA and the possibility of LA-MRSA transfer to humans and other horses. The diagnosis of LA-MRSA in horses can be made by conducting in vitro sensitivity testing for oxacillin and cefoxitin, and then followed by a molecular test using polymerase chain reaction. LA-MRSA transmission in animal hospitals and on farms is most likely due to contact with horses infected or colonized by LA-MRSA. The history of prior antibiotic administration, history of prior LA-MRSA colonization, and length of equine hospitalization were described as risk factors in cases of infection and colonization of LA-MRSA in horses. Nebulized antibiotics may be a viable alternative to use in horses, but nebulized antibiotics are only used in horses that are persistently colonized with LA-MRSA. Controlling the spread of LA-MRSA in horses can be done by regularly washing horses, eradicating vectors in horse stalls such as rats, and maintaining the cleanliness of the stable and animal hospital environment. Meanwhile, cleaning hands, using gloves, and donning protective clothes are ways that humans can prevent the transmission of LA-MRSA when handling horses. This review will explain the definition of LA-MRSA in general, LA-MRSA in horses, the epi­demiology of LA-MRSA in horses, the diagnosis of LA-MRSA in horses, the transmission of LA-MRSA in horses, risk factors for spreading LA-MRSA in horses, public health impact, treatment of LA-MRSA infection in horses, and control of the spread of LA-MRSA in horses.

Staphylococcus aureus Causing Skin and Soft Tissue Infections in Companion Animals: Antimicrobial Resistance Profiles and Clonal Lineages

Staphylococcus aureus is a relevant agent of skin and soft tissue infections (SSTIs) in animals. Fifty-five S. aureus comprising all SSTI-related isolates in companion animals, collected between 1999 and 2018 (Lab 1) or 2017 and 2018 (Lab 2), were characterized regarding susceptibility to antibiotics and heavy metals and carriage of antimicrobial resistance determinants. Clonal lineages were established by PFGE, MLST and agr typing. Over half of the isolates (56.4%, 31/55) were methicillin-resistant S. aureus (MRSA), and 14.5% showed a multidrug resistance (MDR) phenotype. Resistance was most frequently observed for beta-lactams (81.8%, related to blaZ and/or mecA), fluoroquinolones (56.4%) and macrolides/lincosamides (14.5%, related to erm(A) or erm(C)). The distributions of heavy-metal MICs allowed the detection of non-wild-type populations associated with several resistance genes. The collection showed genetic diversity, with prevalence of clonal lineage ST22-agrI (45.5%, 25/55), comprising only MRSA isolates, and several less frequently detected clones, including ST5-agrII (14.6%, 8/55), ST398-agrI (9.1%, 5/55) and ST72-agrI (7.3%, 4/55). This work highlights the high frequency of SSTI-related MRSA strains that reflect the clonal lineages circulating both in companion animals and humans in Portugal, reinforcing the need for a One Health approach when studying staphylococci causing infections in companion animals.

First study on diversity and antimicrobial-resistant profile of staphylococci in sports animals of Southern Thailand

Background and Aim:

Staphylococci are commensal bacteria and opportunistic pathogens found on the skin and mucosa. Sports animals are more prone to injury and illness, and we believe that antimicrobial agents might be extensively used for the treatment and cause the existence of antimicrobial-resistant (AMR) bacteria. This study aimed to investigate the diversity and AMR profile of staphylococci in sports animals (riding horses, fighting bulls, and fighting cocks) in South Thailand.

Materials and Methods:

Nasal (57 fighting bulls and 33 riding horses) and skin swabs (32 fighting cocks) were taken from 122 animals. Staphylococci were cultured in Mannitol Salt Agar and then identified species by biochemical tests using the VITEK^® 2 card for Gram-positive organisms in conjunction with the VITEK^® 2 COMPACT machine and genotypic identification by polymerase chain reaction (PCR). Antimicrobial susceptibility tests were performed with VITEK^® 2 AST-GN80 test kit cards and VITEK^® 2 COMPACT machine. Detection of AMR genes (mecA, mecC, and blaZ) and staphylococcal chromosomal mec (SCCmec) type was evaluated by PCR.

Results:

Forty-one colonies of staphylococci were isolated, and six species were identified, including Staphylococcus sciuri (61%), Staphylococcus pasteuri (15%), Staphylococcus cohnii (10%), Staphylococcus aureus (7%), Staphylococcus warneri (5%), and Staphylococcus haemolyticus (2%). Staphylococci were highly resistant to two drug classes, penicillin (93%) and cephalosporin (51%). About 56% of the isolates were methicillin-resistant staphylococci (MRS), and the majority was S. sciuri (82%), which is primarily found in horses. Most MRS (82%) were multidrug-resistant. Almost all (96%) of the mecA-positive MRS harbored the blaZ gene. Almost all MRS isolates possessed an unknown type of SCCmec. Interestingly, the AMR rate was notably lower in fighting bulls and cocks than in riding horses, which may be related to the owner’s preference for herbal therapy over antimicrobial drugs.

Conclusion:

This study presented many types of staphylococci displayed on bulls, cocks, and horses. However, we found a high prevalence of MRS in horses that could be transmitted to owners through close contact activities and might be a source of AMR genotype transmission to other staphylococci.

Patterns of antimicrobial, multidrug and methicillin resistance among Staphylococcus spp. isolated from canine specimens submitted to a diagnostic laboratory in Tennessee, USA: a descriptive study

Background

Multidrug- and methicillin-resistant staphylococci are both veterinary and public health concerns due to their zoonotic potential. Therefore, the objective of this study was to investigate patterns of antimicrobial, multidrug, and methicillin resistance among four Staphylococcus spp. commonly isolated from canine clinical specimens submitted to the Clinical Bacteriology Laboratory at the University of Tennessee College of Veterinary Medicine (UTCVM).

Methods

Results of antimicrobial susceptibility testing and mecA polymerase chain reaction (PCR) for isolates of four common Staphylococcus spp. isolates were obtained from the Bacteriology Laboratory at the UTCVM between 01/01/2006 and 12/31/2017. Cochran-Armitage trend test was used to assess temporal trends of antimicrobial resistance (AMR), multidrug resistance (MDR), and methicillin resistance. Kappa test of agreement was used to assess agreement between the results of PCR and disk diffusion tests.

Results

Most of the 7805 isolates were S. pseudintermedius (6453 isolates), followed by S. coagulans (860), S. aureus (330), and S. schleiferi (162). Among S. pseudintermedius isolates, 45.5% were MDR, and 30.8% were methicillin-resistant (MRSP). There was a significant temporal increase in MRSP (p = 0.017). Chloramphenicol resistance increased among both MRSP and methicillin-susceptible (MSSP) isolates (p <  0.0001). Among S. aureus isolates, 40.9% were MDR, 37.4% were methicillin-resistant (MRSA), and the proportion of MRSA isolates increased significantly (p = 0.0480) over time. There was an increasing temporal trend in the proportion of MDR isolates among MSSP (p = 0.0022), but a decrease among MRSP (p <  0.0001) and MRSA (p = 0.0298). S. schleiferi had the highest percentage (56.9%) of methicillin-resistant isolates. Oxacillin disk diffusion was superior to cefoxitin for the detection of mecA-mediated resistance and had almost perfect agreement with mecA PCR assay for S. pseudintermedius (95.4% agreement, kappa (κ) = 0.904; p <  0.0001), S. coagulans (95.6%, κ = 0.913; p <  0.0001) and S. schleiferi (97.7%, κ = 0.945; p <  0.0001). However, cefoxitin disk diffusion was superior to oxacillin disk diffusion and had almost perfect agreement with mecA PCR assay for S. aureus (95.3%, κ = 0.834; p <  0.0001).

Conclusions

The levels of resistance and increasing temporal trends are concerning. These findings have implications for treatment decisions and public health due to the zoonotic potential of staphylococci. Continued surveillance and use of antibiograms to guide clinical decisions will be critical.

Assessment of animal diseases caused by bacteria resistant to antimicrobials: Horses

In this opinion, the antimicrobial‐resistant bacteria responsible for transmissible diseases that constitute a threat to the health of horses have been assessed. The assessment has been performed following a methodology composed of information collected via an extensive literature review and expert judgement. Details on the methodology used for this assessment are explained in a separate opinion. A global state of play of antimicrobial‐resistant Actinobacillus equuli, Dermatophilus congolensis, Enterococcus spp., Escherichia coli, Klebsiella pneumoniae, Pasteurella spp., Pseudomonas aeruginosa, Rhodococcus equi, Staphylococcus aureus and Streptococcus dysgalactiae subsp. dysgalactiae/equisimilis and Streptococcus equi subsp. equi and subsp. zooepidemicus has been provided. Among those bacteria, EFSA identified E. coli, Staphylococcus aureus and R. equi with more than 66% certainty as the most relevant antimicrobial‐resistant bacteria in the EU, given their importance as causative agents of clinical disease in horses and the significant levels of resistance to clinically relevant antimicrobials. The animal health impact of these ‘most relevant’ bacteria as well as their eligibility of being listed and categorised within the animal health law framework will be assessed in separate scientific opinions.

Livestock-Associated Meticillin-Resistant Staphylococcus aureus—Current Situation and Impact From a One Health Perspective

Purpose of Review

In this article, we aim to provide an overview of the occurrence and characteristics of livestock-associated (LA-) meticillin-resistant Staphylococcus aureus (MRSA). We further question the role of LA-MRSA as a potential foodborne pathogen. We investigate recent findings and developments from a One Health perspective also highlighting current strategies and initiatives aiming to improve reporting, control, and prevention of LA-MRSA.

Recent Findings

While the overall number of invasive MRSA infections in humans is decreasing (in most European countries and the USA) or steadily increasing (in the Asia-Pacific region), the role of LA-MRSA as causative agent of invasive disease and as potential foodborne pathogen is still poorly understood. LA-MRSA prevalence in livestock remains high in many geographical regions and the acquisition of new virulence and resistance determinants constitutes a growing threat for human health.

Summary

The true incidence of LA-MRSA infections due to occupational exposure is unknown. Improved MRSA monitoring and tracking procedures are urgently needed. Strain typing is crucial to enable improved understanding of the impact of LA-MRSA on human and animal health.

Antibiotic Resistance, spa Typing and Clonal Analysis of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Blood of Patients Hospitalized in the Czech Republic

Staphylococcus aureus is one of the major causes of bloodstream infections. The aim of our study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates from blood of patients hospitalized in the Czech Republic between 2016 and 2018. All MRSA strains were tested for antibiotic susceptibility, analyzed by spa typing and clustered using a Based Upon Repeat Pattern (BURP) algorithm. The representative isolates of the four most common spa types and representative isolates of all spa clonal complexes were further typed by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. The majority of MRSA strains were resistant to ciprofloxacin (94%), erythromycin (95.5%) and clindamycin (95.6%). Among the 618 strains analyzed, 52 different spa types were detected. BURP analysis divided them into six different clusters. The most common spa types were t003, t586, t014 and t002, all belonging to the CC5 (clonal complex). CC5 was the most abundant MLST CC of our study, comprising of 91.7% (n = 565) of spa-typeable isolates. Other CCs present in our study were CC398, CC22, CC8, CC45 and CC97. To our knowledge, this is the biggest nationwide study aimed at typing MRSA blood isolates from the Czech Republic.

Methicillin-Resistant Staphylococcus aureus Clonal Complex 398 as a Major MRSA Lineage in Dogs and Cats in Thailand

The aim of this study was to present molecular and antimicrobial resistance characteristics of methicillin-resistant Staphylococcus aureus (MRSA) clonal complex (CC) 398 isolated from diseased dogs and cats in Thailand. A total of 20 MRSA isolates of 134 Staphylococcus aureus isolated from canine and feline clinical samples during 2017-2020 were CC398, consisting of sequence type (ST) 398 (18 isolates), ST5926 (1 isolate), and ST6563 (1 isolate) by multilocus sequence typing. spa t034 and staphylococcal cassette chromosome mec (SCCmec) V were predominantly associated with ST398. Intraclonal differentiation was present by additional spa (t1255, t4653), non-detectable spa, composite SCCmec with a hybrid of ccrA1B1+ccrC and class A mec complex, and DNA fingerprints by pulsed-field gel electrophoresis. The isolates essentially carried antimicrobial resistance genes, mediating multiple resistance to β-lactams (mecA, blaZ), tetracyclines [tet(M)], aminoglycosides [aac(6')-Ie-aph(2')-Ia], and trimethoprim (dfr). Livestock-associated MRSA ST398 resistance genes including lnu(B), lsa(E), spw, fexA, and tet(L) were heterogeneously found and lost in subpopulation, with the absence or presence of additional erm(A), erm(B), and ileS2 genes that corresponded to resistance phenotypes. As only a single CC398 was detected with the presence of intraclonal variation, CC398 seems to be the successful MRSA clone colonizing in small animals as a pet-associated MRSA in Thailand.

Impact of European pet antibiotic use on enterococci and staphylococci antimicrobial resistance and human health

Due to the inappropriate use of antibiotics described in both human and veterinary medicine, there is emerging evidence of antimicrobial-resistant organisms isolated from humans and pets, forming a multifaceted problem. Although the true magnitude of antimicrobial resistance in pets and other animals, as well as humans, are not fully known; pets, in particular dogs and cats, can contribute to the spread of antimicrobial resistance due to close contact with humans and their status as a family member in urban households. This review summarizes and highlights the current data concerning the antibiotic use on pets, and the European distribution of the increasing prevalence of multiresistant bacterial pathogens, such as enterococci and methicillin-resistant staphylococci on pets, as well as its implications for public health.

Investigation of the environmental presence of multidrug-resistant bacteria at small animal hospitals in Hungary

Multidrug-resistant bacteria can cause severe nosocomial infections in both human and veterinary clinics. The aim of this study was to investigate the presence and antibiotic susceptibility of Enterococcus, Staphylococcus and Pseudomonas strains at four small animal clinics of Hungary in 2018, as these bacteria can reliably represent the level of antimicrobial resistance in the investigated environment. A total of 177 Staphylococcus colonies were found, including 22 Staphylococcus pseudintermedius and 13 Staphylococcus aureus. As regards enterococci, 9 Enterococcus faecium, 2 E. faecalis and further 286 Enterococcus strains were isolated. The number of Pseudomonas aeruginosa isolates (n = 34) was considered too low for relevant susceptibility testing. Among staphylococci, the highest resistance was found to sulphamethoxazole (82.9%), penicillin (65.7%) and erythromycin (54.3%), while in the case of enterococci, resistance to norfloxacin and rifampicin was the most common, with 25.5% of the strains being resistant to both antibiotics. Ten methicillin-resistant S. pseudintermedius (MRSP) and six vancomycin-resistant Enterococcus (VRE) strains could be identified. Only 5.7% of the Staphylococcus isolates were susceptible to all tested agents, while this ratio was 36.2% among enterococci. The results of this study have revealed a high prevalence of antibiotic-resistant bacteria in Hungarian small animal clinics, which highlights the importance of regular disinfection processes and stringent hygiene measures in veterinary clinics.

Molecular Epidemiology of Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus in Wild, Captive and Laboratory Rats: Effect of Habitat on the Nasal S. aureus Population

Rats are a reservoir of human- and livestock-associated methicillin-resistant Staphylococcus aureus (MRSA). However, the composition of the natural S. aureus population in wild and laboratory rats is largely unknown. Here, 144 nasal S. aureus isolates from free-living wild rats, captive wild rats and laboratory rats were genotyped and profiled for antibiotic resistances and human-specific virulence genes. The nasal S. aureus carriage rate was higher among wild rats (23.4%) than laboratory rats (12.3%). Free-living wild rats were primarily colonized with isolates of clonal complex (CC) 49 and CC130 and maintained these strains even in husbandry. Moreover, upon livestock contact, CC398 isolates were acquired. In contrast, laboratory rats were colonized with many different S. aureus lineages—many of which are commonly found in humans. Five captive wild rats were colonized with CC398-MRSA. Moreover, a single CC30-MRSA and two CC130-MRSA were detected in free-living or captive wild rats. Rat-derived S. aureus isolates rarely harbored the phage-carried immune evasion gene cluster or superantigen genes, suggesting long-term adaptation to their host. Taken together, our study revealed a natural S. aureus population in wild rats, as well as a colonization pressure on wild and laboratory rats by exposure to livestock- and human-associated S. aureus, respectively.

Methicillin-resistant Staphylococcus aureus in veterinary professionals in 2017 in the Czech Republic

Background

Cases of colonization or infection caused by Methicillin-resistant Staphylococcus aureus (MRSA) are frequently reported in people who work with animals, including veterinary personnel. The aim of this study was to determine the prevalence of MRSA colonization among veterinary professionals. A total of 134 nasal swabs from healthy attendees of a veterinary conference held in the Czech Republic were tested for presence of MRSA. The stains were further genotypically and phenotypically characterized.

Results

Nine isolated MRSA strains were characterized with sequence type (ST), spa type (t) and Staphylococcal Cassette Chromosome mec type. Five different genotypes were described, including ST398-t011-IV (n = 5), ST398-t2330-IV (n = 1), ST398-t034-V (n = 1), ST225-t003-II (n = 1) and ST4894-t011-IV (n = 1). The carriage of the animal MRSA strain was confirmed in 8 cases, characteristics of one strain corresponded to the possible nosocomial origin. Among animal strains were described three spa types (t011, t034, t2330) belonging into one dominating clonal complex spa-CC11.

Conclusion

According to our results, the prevalence of nasal carriage of MRSA in veterinary personnel is 6.72%. Although we described an increase compared to the results of previous study (year 2008), the prevalence in the Czech Republic is still remaining lower than reported from neighboring countries. Our results also indicate that healthcare - associated MRSA strains are still not spread among animals.

Predominance of methicillin-resistant Staphylococcus aureus SCCmec type II-CC5 and SCCmec type IV-CC1/CC8 among companion animal clinical isolates in Japan: Findings from phylogenetic comparison with human clinical isolates

OBJECTIVES

To characterise the genotypic profiles of methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates from companion animals and to investigate their association with those from humans in Japan.

METHODS

Non-duplicated MRSA clinical isolates recovered between July 2016 and January 2018 were analysed. The MRSA isolates were typed by polymerase chain reaction (PCR)-based open reading frame (ORF) typing (POT) scores, SCCmec types, multilocus sequence typing, and virulence gene profiles. Phylogenetic comparison of those isolates with previously described human isolates was performed.

RESULTS

Among 56 MRSA isolates (33 cats, 20 dogs and three rabbits), 26 isolates with a POT1 score of 93, SCCmec type II mostly belonged to CC5, including ST5. Twenty-six isolates with a POT1 score of 106, SCCmec type IV showed diversity of STs: 15 isolates belonged to CC8, mainly including ST8, and 11 isolates belonged to CC1, including ST1 and newly identified STs 4768, 4775, and 4779. Two cat isolates were ST8-SCCmec type IV possessing pvl/ACME-arcA, presumed to be the hypervirulent community-associated MRSA (CA-MRSA) clone USA300. Notably, all three rabbit isolates belonged to ST4768. The POT1 score 106 CA-MRSA isolates from animals and humans were divided into two large clusters of CC1 and CC8, where host species-specific sub-clusters were not identified within each cluster. A large cluster of POT1 score 93 healthcare-associated MRSA (HA-MRSA) isolates from animals and humans consisted of sub-clusters formed exclusively by the vast majority of human isolates and those formed by animal and human isolates.

CONCLUSION

Companion animals could be potential reservoirs and vehicles for the transmission of CA-MRSA to humans, and could transmit companion animal-adaptive HA-MRSA lineages to humans as their second reservoirs.

Increased genetic diversity of methicillin-resistant Staphylococcus aureus (MRSA) isolated from companion animals

The aim of the present study was to investigate the diversity of methicillin-resistant Staphylococcus aureus (MRSA) that originated from Austrian companion animals during the last five-year period. A total of 90 non-repetitive MRSA isolates were obtained during diagnostic activities from autumn 2013 to autumn 2018. They originated from horses (n = 62), cats (n = 13), dogs (n = 10), rabbits (n = 2), a domestic canary, a zoo-kept hammer-headed bat (Hypsignathus monstrosus) and a semi-captive northern bald ibis (Geronticus eremita). Antimicrobial susceptibility testing was performed. All isolates were mecA-positive and mecC-negative. The isolates were genotyped by SCCmec, spa and dru typing, Multiple-Locus Variable number of tandem repeat Analyses (MLVA), S. aureus DNA microarray, and whole-genome sequencing (WGS). Eight sequence types (STs - ST398, ST5275 (new ST), ST225, ST8, ST22, ST152, ST1, and ST45), three SCCmec types (II, IV, and V), sixteen spa types (t003, t008, t011, t015, t032, t034, t1381, t1928, t1985, t223, t334, t355, t430, t6447, t6867, and t7105), fourteen dru types (dt10a, dt10az, dt10q, dt10r, dt11a, dt5e, dt6j, dt9a, dt9ak, dt9g, and four new types dt8as, dt7ak, dt4j, dt14n), and thirty-five MLVA types were detected. WGS-based core genome MLST (cgMLST) displayed five main clusters. Compared to the time period 2004-2013, the results of the present study show not only a higher diversity among the MRSA isolates within the population of Austrian companion animals, but also the introduction of new clones. Although ST398 isolates remained predominant, mainly due to high presence of this lineage among horses, increasing isolation rates of human-associated MRSA clones were observed in cats and dogs.

A cross-sectional study of methicillin-resistant Staphylococcus aureus at the equine-human interface

The present study aimed at investigating the percent prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in equines and associated personnel. A total of 150 swabs of equines and 50 nasal swab samples of associated personnel were collected. These samples were processed in mannitol salt broth for enrichment. A total of 175 nasal swab samples changed the broth color from pink to yellow which were detected as samples containing S. aureus. These samples were processed further on specific media, namely mannitol salt agar, Staph-110, and blood agar, for phenotypic and Gram's staining-based confirmation of S. aureus isolates. Out of these 175 S. aureus-positive samples, 150 were of equine and 25 were of human origin. Identification of MRSA isolates in 175 S. aureus-positive samples was carried out by antimicrobial susceptibility testing by disc diffusion method. Results showed the presence of MRSA in 87 samples, out of which 81 samples were collected from equines and six samples from humans. Results of antibiotic testing revealed that percentage positivity of MRSA was higher (54%) in equines as compared with the associated personnel (24%). Most resistant antibiotics against MRSA isolates were oxacillin and methicillin while linezolid was found to be the most sensitive antibiotic against MRSA. In conclusion, our findings indicated prevalence of MRSA in equines and associated personnel evidencing an occupational risk of contracting MRSA from horses.

Characterisation of Staphylococcus aureus strain causing severe respiratory disease in rabbits

<em>Staphylococcus aureus</em> is acknowledged as one of the important pathogens isolated from humans and animals. However, the <em>S. aureus</em> causing severe respiratory diseases in rabbits have not been well characterised. A <em>S. aureus</em> named FZHW001, isolated from the lungs of dead rabbits with severe respiratory disease, was characterised by artificial infection of rabbits, detection of virulence factors, multi-locus sequencing typing and antimicrobial susceptibility test. The FZHW001 infected rabbits showed identical respiratory symptoms to those of naturally infected ones, and the isolate could spread through directed contact among rabbits. The isolate was typed into clonal complex 121 and carried 7 of 13 tested virulence factors. Furthermore, the isolate was identified to be methicillin-susceptible <em>S. aureus</em> and was susceptible to 7 of 12 tested antibiotics. This study first describes the characteristics of <em>S. aureus</em> isolated from rabbits causing severe respiratory disease, which will help in further understanding the pathogenic mechanisms of <em>S. aureus</em> in rabbits.

Death Associated to Methicillin Resistant Staphylococcus aureus ST8 Infection in Two Dolphins Maintained Under Human Care, Italy

The present study describes the isolation of Methicillin-resistant Staphylococcus aureus (MRSA) from respiratory tract of 2 dolphins of different origin, a stranded juvenile Risso's dolphin (Grampus griseus) and a captive born common bottlenose dolphin (Tursiops truncatus) calf, which died in the same institution at 1-month distance from the other. A complete microbiological and genetic investigation confirmed the presence of MRSA clone-complex 8, sequence type (ST) 8, spa-type t008 in both individuals. This strain differs from the one previously reported in walruses and dolphins and has never been described in dolphins before, but it is randomly isolated from Italian human patients. Vertical transmission of the infection may also occurs in other species and considering the description and location of the pathological lesions, this seems to be the most likely route of transmission implied in the young bottlenose dolphin. Staphylococcus aureus is known as an opportunistic agent, usually secondary to other pathogens, but its multiple antibiotic resistance and its zoonotic implications suggest a thorough and strict application of animal management hygiene protocols.

Investigation of methicillin-resistant Staphylococcus aureus among clinical isolates from humans and animals by culture methods and multiplex PCR

Background

Staphylococcus aureus is responsible for large numbers of hospital-related and community-acquired infections. In this study, we investigated the presence of S. aureus and methicillin-resistant S. aureus (MRSA) in 100 samples from animals (55 cattle, 36 dogs, and 9 cats) and 150 samples from hospitalized human patients. The samples were collected from healthy and diseased animals and from diseased humans and included milk, wound swab, pus, exudates, nasal swab and diabetic ulcer. Initially, S. aureus was isolated and identified by colony morphology, Gram staining, and biochemical tests (catalase and coagulase tests). The S. aureus-positive samples were examined by polymerase chain reaction (PCR) to determine their MRSA status.

Results

Of the 100 animal samples, 29 were positive for S. aureus. Four samples (13.8%) from dogs were MRSA-positive, but samples from cattle and cats were MRSA-negative. Of the 150 human samples we collected, 64 were S. aureus-positive and, of these, 34 (53.1%) were MRSA-positive. Most (28%) of the MRSA samples were isolated from surgical wound swabs, followed by the pus from skin infections (11%), exudates from diabetic ulcers (6%), exudates from burns (4%), and aural swabs (3%). By contrast, a low MRSA detection rate (n = 4) was seen in the non-human isolates, where all MRSA bacteria were isolated from nasal swabs from dogs. The antimicrobials susceptibility testing results showed that S. aureus isolates with mecA genes showed resistance to penicillin (100%), oxacillin (100%), erythromycin (73.5%), ciprofloxacin (70.6%), and gentamicin (67.7%). The lowest resistance was found against ceftazidime, and no vancomycin-resistant isolates were obtained.

Conclusions

We detected S. aureus and MRSA in both human and canine specimens. Isolates were found to be resistant to some of the antimicrobials available locally. MRSA carriage in humans and animals appears to be a great threat to effective antimicrobials treatment. The prudent use of antimicrobials will reduce the antimicrobial resistance. Our findings will help to find the most appropriate treatment and to reduce antimicrobial resistance in the future by implementing prudent use of antimicrobials. Further studies are required to better understand the epidemiology of MRSA human–animal inter-species transmission in Bangladesh.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1611-0) contains supplementary material, which is available to authorized users.