Methicillin-resistant coagulase-negative staphylococci from healthy dogs in Nsukka, Nigeria

Canine Staphylococcaceae circulating in a Kenyan animal shelter

Animal shelters, especially in resource-poor countries, bring together pets from different regions and with different backgrounds. The crowding of such animals often results in infectious diseases, such as respiratory infections. This study characterized Staphylococcaceae from diseased and apparently healthy dogs housed in an animal shelter in Kenya, to determine their antibiotic resistance profiles, their genetic relatedness, and the presence of dominant clones. Therefore, bacteria were collected from all 167 dogs present in the shelter in June 2015 and screened for Staphylococcaceae using standard cultivation techniques. In all, 92 strains were isolated from 85 dogs and subsequently sequenced by PacBio long-read sequencing. Strains encompassed nine validated species, while S. aureus (n = 47), S. pseudintermedius (n = 21), and Mammaliicoccus (M.) sciuri (n = 16) were the three most dominant species. Two S. aureus clones of ST15 (CC15) and ST1292 (CC1) were isolated from 7 and 37 dogs, respectively. All 92 strains isolated were tested for their antimicrobial susceptibility by determining the minimum inhibitory concentrations. In all, 86 strains had resistance-associated minimal inhibitory concentrations to at least one of the following antimicrobials: tetracycline, benzylpenicillin, oxacillin, erythromycin, clindamycin, trimethoprim, kanamycin/gentamicin, or streptomycin. Many virulence-encoding genes were detected in the S. aureus strains, other Staphylococcaceae contained a different set of homologs of such genes. The presence of mobile genetic elements, such as plasmids and prophages, known to facilitate the dissemination of virulence- and resistance-encoding genes, was also assessed. The unsuspected high presence of two S. aureus clones in about 50% of dogs suggests dissemination within the shelter and a human source.IMPORTANCEMicrobiological data from sub-Saharan Africa are scarce compared to data from North America, Europe, or Asia, and data derived from dogs, the man's best friend, kept in sub-Saharan Africa are largely missing. This work presents data on Staphylococcaceae mainly isolated from the nasal cavity of dogs stationed at a Kenyan shelter in 2015. We characterized 92 strains isolated from 85 dogs, diseased and apparently healthy ones. The strains isolated covered nine validated species and we determined their phenotypic resistance and characterized their complete genomes. Interestingly, Staphylococcus aureus of two predominant genetic lineages, likely to be acquired from humans, colonized many dogs. We also detected 15 novel sequence types of Mammaliicoccus sciuri and S. pseudintermedius indicating sub-Saharan-specific phylogenetic lineages. The data presented are baseline data that guide antimicrobial treatment for dogs in the region.

Epidemiology and antimicrobial resistance of staphylococci other than Staphylococcus aureus from domestic animals and livestock in Africa: a systematic review

Introduction

Staphylococci other than Staphylococcus aureus (SOSA) in animals are becoming more pathogenic and antibiotic resistant and can potentially disseminate to humans. However, there is little synthesized information regarding SOSA from animals in Africa. This systematic review provides a comprehensive overview of the epidemiology and antimicrobial resistance of SOSA in companion animals (pets) and livestock in Africa.

Method

This systematic review (PROSPERO-CRD42021252303) was conducted according to the PRISMA guidelines, and 75 eligible studies from 13 countries were identified until August 2022. Three electronic databases (Pubmed, Scopus and Web of Science) were employed.

Results

The frequently isolated SOSA were S. epidermidis, S. intermedius, S. pseudintermedius, S. xylosus, S. chromogenes, S. hyicus, M. sciuri, S. hominis, and S. haemolyticus. Thirty (40%) studies performed antibiotic susceptibility testing (AST). Penicillin (58%) and tetracycline (28%) resistance were most common across all SOSA with high rates of resistance to aminoglycosides, fluoroquinolones, and macrolides in some species. Resistance to last-resort antibiotics such as linezolid and fusidic acid were also reported. Limited data on strain typing and molecular resistance mechanisms precluded analysis of the clonal diversity of SOSA on the continent.

Conclusion

The findings of this review indicate that research on livestock-associated SOSA in Africa is lacking in some regions such as Central and Western Africa, furthermore, research on companion animals and more advanced methods for identification and strain typing of SOSA need to be encouraged.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021252303.

Animal contact and paediatric acute febrile illness in Greater Accra Region, Ghana

Objective

To examine the association between animal contact (primarily dogs and cats) and non-malarial fever, as well as with secondary symptoms of headache, nausea, vomiting, and cough, in 687 children in Greater Accra Region, Ghana.

Design

Cross-sectional study of acute febrile illness among children aged 1-15 years old between October 2016 and August 2017.

Setting

Ledzokuku-Krowor Municipal Assembly (LEKMA) Hospital, Teshie, Greater Accra Region.

Participants

The study included children with acute fever, defined as a measured temperature of greater than 37.5°C, occurring less than seven days before the hospital visit, and afebrile children as controls.

Main outcome measures

Measured fever, self-reported fever, and secondary symptoms, each adjusting for patient household characteristics.

Results

Animal contact was neither associated with measured fever (OR = 1.04, 95% CI 0.73-1.49) nor with self-reported fever (OR = 0.97, 95% CI 0.68-1.39). Animal contact was associated with headache (OR = 3.26, 95% CI 2.23-4.77, P < .01) and nausea (OR = 3.05, 95% CI 1.99-4.68, P < .01), but not with vomiting or cough. Additional models that used alternate inclusion criteria to define non-malarial fever yielded similar results. Several bacterial zoonoses that could plausibly have been transmitted by dogs and cats were diagnosed in the study population.

Conclusion

These findings suggest the need for future studies to evaluate animal contact as a risk factor for bacterial zoonoses that may serve as an etiological driver of acute febrile illness.

Funding

no external funding.

Antibiotic susceptibility pattern of canine coagulase positive and coagulase negative Staphylococcus spp. in a hot and dry region of India

The emergence of anti microbial resistance among Staphylococcus spp. isolated from clinical cases of canines should be continuously monitored hence the present study was formulated to ascertain the antibiotypes and methicillin resistance in coagulase positive and coagulase negative staphylococci of canine skin and associated mucous membrane affections from a hot and dry region of India. A total of 165 clinical samples were collected and Staphylococcus aureus was identified by conventional bacteriological methods and PCR. Antibiotic susceptibility test was done against commercially available antibiotic impregnated discs as per Clinical and Laboratory Standards Institute (CLSI) method. Methicillin resistance was determined by plate methods and then via PCR of mecA gene. These 165 samples yielded, 88 (53.33%) isolates of genus Staphylococcus and 46 Staphylococcus aureus and 51/88 (57.95%) isolates were coagulase positive staphylococci. Total 55 (62.5%) isolates showed susceptibility to Ceftriaxone/Sulbactum, 37 (42.05%) to Ciprofloxacin, 26 (29.55 %) to Oxacillin, 24 (27.27 %) to Penicillin, and 10 (11.36 %) to Gentamicin. Total 21 methicillin resistant Staphylococcus aureus (MRSA) and 12 methicillin resistant coagulase negative staphylococci (MRCoNS) were found on phenotypic basis whereas the mecA gene was detected in 6 /21 MRSA and 2 /12 MRCoNS isolates. Staphylococcus spp. showed increased level of resistance against commonly used antibiotics. The higher prevalence of methicillin resistance found with phenotypic methods than to mecA PCR indicates towards additional mechanisms responsible for emergence of MRS, especially in CoNS.

Evidence of Methicillin Resistant Staphylococcus Aureus (MRSA) in Pet and Stray Dogs Within Sokoto Metropolis, Nigeria

Methicillin Resistant Staphylococcus aureus (MRSA) is an important zoonotic pathogen capable of causing life threatening disease conditions in humans. A cross-sectional study was conducted to investigate the presence of MRSA in both pet and stray dogs within the Sokoto metropolis. A total of 100 oral swabs comprising 50 each from pet and stray dogs were collected and analyzed using routine bacteriological cultures and molecular identifications. Out of the 100 samples examined, 15 % (15/100) were positive for MRSA with varying detection rates of 9/50 (18 %) and 6/50 (12 %) for the pet and stray dogs respectively. The statistical analysis showed no significant association between the occurrence of MRSA and the dogs (P = 0.401). The study revealed the presence of MRSA in dogs within the Sokoto metropolis, which presents health risks to pet dog owners, veterinarians, dog catchers and other individuals who may come into close contact with these dogs.

Isolation and Identification of Staphylococcus Species Obtained from Healthy Companion Animals and Humans

The close contact between people and their pets has generated the exchange of skin microbiota, accompanied by bacteria that present resistance to antibiotics. Staphylococcus spp., opportunistic pathogens present in the skin and mucosa of mammals, have had their importance recognized in human and veterinary medicine. The objectives of this study were to identify Staphylococcus spp. present in isolates from the nostrils of healthy humans, dogs and cats as well as to determine their phenotype of resistance to methicillin. Strain identification was performed by MALDI-TOF mass spectrometry and antimicrobial susceptibility was determined using a disk diffusion assay for 12 antibiotics. Sixty humans (veterinary and technicians), sixty dogs and sixty cats were sampled; of them, 61.6%, 56.6% and 46.6%, respectively, carried Staphylococcus spp. in their nostrils, and only two people carried two different species of Staphylococcus in the only anatomical site sampled. A methicillin-resistant phenotype was present in 48.7% of the humans, 26.5% of the dogs and 57.1% of the cats, and sampled. These results demonstrate the presence of Staphylococcus spp. strains resistant to methicillin in personnel who work in contact with animals, as well as in dogs and cats that entered the same hospital or veterinary clinic, which alerts us to the potential transfer of these strains to or between people, dogs and/or cats.

Multidrug-resistant bacteria isolated from surgical site of dogs, surgeon's hands and operating room in a veterinary teaching hospital in Brazil

Surgical environment can play as a source of multidrug-resistance organism, what can pose as a big threat to the patients and health care professionals. This study aimed to evaluate the prevalence and antimicrobial resistance profile of Gram-positive cocci (GPC) and Gram-negative bacilli (GNB) isolated from the surgical environment. All samples were collected during the intraoperative period of clean/clean-contaminated (G1) and contaminated (G2) surgery. A total of 150 samples were collected from the superficial surgical site in the beginning (n=30) and the end (n=30) of the procedure, surgeon's hands before (n=30) and after (n=30) antisepsis, and the surgical environment (n=30). MALDI-TOF MS and antimicrobial susceptibility testing by disk diffusion method were performed for species identification, and determination of the resistance profile. Sixty-eight isolates of GPC and 15 of GNB were obtained. Staphylococcus spp. were the most frequent species isolated from surgical site (55.26% [21/38]), surgeon's hands (46.15% [6/13]), and environment (56.67% [17/30]). GPC were mostly resistance to penicillin (85.71% [54/63]), and erythromycin (77.78% [49/63]), and GNB were mostly resistance to cefazolin (58.33% [7/12]), and azithromycin (58.33% [7/12]). High incidence of multidrug resistance was observed in coagulase-negative staphylococci (86.21% [25/29]), coagulase-positive staphylococci (86.67% [13/15]), Enterococcus spp. (68.42% [13/19]) and Gram-negative bacilli (60% [9/15]). The high rate of resistance of commensal bacteria found in our study is worrying. Coagulase-negative staphylococci are community pathogens related to nosocomial infections in human and veterinary hospitals, their presence in healthy patients and in veterinary professionals represent an important source of infection in the one health context. Continuous surveillance and application of antimicrobial stewardship programs are essential in the fight against this threat.

Multi-species host range of staphylococcal phages isolated from wastewater

The host range of bacteriophages defines their impact on bacterial communities and genome diversity. Here, we characterize 94 novel staphylococcal phages from wastewater and establish their host range on a diversified panel of 117 staphylococci from 29 species. Using this high-resolution phage-bacteria interaction matrix, we unveil a multi-species host range as a dominant trait of the isolated staphylococcal phages. Phage genome sequencing shows this pattern to prevail irrespective of taxonomy. Network analysis between phage-infected bacteria reveals that hosts from multiple species, ecosystems, and drug-resistance phenotypes share numerous phages. Lastly, we show that phages throughout this network can package foreign genetic material enclosing an antibiotic resistance marker at various frequencies. Our findings indicate a weak host specialism of the tested phages, and therefore their potential to promote horizontal gene transfer in this environment.

Methicillin-Resistant Coagulase Negative Staphylococci and Their Antibiotic Susceptibility Pattern from Healthy Dogs and Their Owners from Kathmandu Valley

This cross-sectional study was designed to identify information on the frequency, antimicrobial resistance and species diversity of methicillin-resistant coagulase negative staphylococci (MRCoNS) among pet dogs and humans within households. Fifty five nasal swabs each from dogs and their owners were collected. MRCoNS were identified based on gram staining, culture on mannitol salt agar, biochemical tests, and mecA gene amplification. The antibiotic susceptibility of the isolates was assessed by a disc diffusion test. Uniplex and multiplex polymerase chain reaction (PCR) were employed for the species identification of MRCoNS and SCCmec typing, respectively. Species were further confirmed by MALDI-TOF-MS. The prevalence of MRCoNS was 29% in dog owners and 23.6% in dogs. Four different species of MRCoNS, Staphylococci saprophyticus (48.3%), S. haemolyticus (24.1%), S. warneri (17.2%), and S. epidermidis (10.3%), were detected. Two isolates each from dog owners and dogs showed a constitutive resistance to macrolide-lincosamide-streptogramin B (cMLSB) resistance, eight isolates each from dogs and their owners showed a macrolide-streptogramin B (MSB) resistance, and only two isolates from dog owners revealed an inducible resistance to macrolide-lincosamide-streptogramin B (iMLSB) resistance. SCCmec types were SCCmec type IV (55.2%), SCCmec type V (24.1%), SCCmec III (10.3%), SCCmec II (3.4%); two isolates were non-typable. MRCoNS are prevalent and genetically diverse in companion animals and humans. Different species of MRCoNS were found in dogs and their owners.

The Resistome and Mobilome of Multidrug-Resistant Staphylococcus sciuri C2865 Unveil a Transferable Trimethoprim Resistance Gene, Designated dfrE, Spread Unnoticed

Methicillin-resistant Staphylococcus sciuri (MRSS) strain C2865 from a stranded dog in Nigeria was trimethoprim (TMP) resistant but lacked formerly described staphylococcal TMP-resistant dihydrofolate reductase genes (dfr). Whole-genome sequencing, comparative genomics, and pan-genome analyses were pursued to unveil the molecular bases for TMP resistance via resistome and mobilome profiling. MRSS C2865 comprised a species subcluster and positioned just above the intraspecies boundary. Lack of species host tropism was observed. S. sciuri exhibited an open pan-genome, while MRSS C2865 harbored the highest number of unique genes (75% associated with mobilome). Within this fraction, we discovered a transferable TMP resistance gene, named dfrE, which confers high-level TMP resistance in Staphylococcus aureus and Escherichia coli. dfrE was located in a novel multidrug resistance mosaic plasmid (pUR2865-34) encompassing adaptive, mobilization, and segregational stability traits. dfrE was formerly denoted as dfr_like in Exiguobacterium spp. from fish farm sediment in China but escaped identification in one macrococcal and diverse staphylococcal genomes in different Asian countries. dfrE shares the highest identity with dfr of soil-related Paenibacillus anaericanus (68%). Data analysis discloses that dfrE has emerged from a single ancestor and places S. sciuri as a plausible donor. C2865 unique fraction additionally enclosed novel chromosomal mobile islands, including a multidrug-resistant pseudo-SCCmec cassette, three apparently functional prophages (Siphoviridae), and an SaPI4-related staphylococcal pathogenicity island. Since dfrE seems not yet common in staphylococcal clinical specimens, our data promote early surveillance and enable molecular diagnosis. We evidence the genome plasticity of S. sciuri and highlight its role as a resourceful reservoir for adaptive traits.

IMPORTANCE The discovery and surveillance of antimicrobial resistance genes (AMRG) and their mobilization platforms are critical to understand the evolution of bacterial resistance and to restrain further expansion. Limited genomic data are available on Staphylococcus sciuri; regardless, it is considered a reservoir for critical AMRG and mobile elements. We uncover a transferable staphylococcal TMP resistance gene, named dfrE, in a novel mosaic plasmid harboring additional resistance, adaptive, and self-stabilization features. dfrE is present but evaded detection in diverse species from varied sources geographically distant. Our analyses evidence that the dfrE-carrying element has emerged from a single ancestor and position S. sciuri as the donor species for dfrE spread. We also identify novel mobilizable chromosomal islands encompassing AMRG and three unrelated prophages. We prove high intraspecies heterogenicity and genome plasticity for S. sciuri. This work highlights the importance of genome-wide ecological studies to facilitate identification, characterization, and evolution routes of bacteria adaptive features.

Determination of the frequency, species distribution and antimicrobial resistance of staphylococci isolated from dogs and their owners in Trinidad

The close contact between humans and their dogs can lead to the commingling of staphylococci and the exchange of mobile genetic elements encoding antimicrobial resistance. The objectives of this study were to determine the species distribution and antimicrobial resistance patterns of staphylococci colonizing canine pets and their owners in Trinidad. Staphylococci were isolated from canine pets and their owners and identified using MALDI-TOF mass spectrometry. Antimicrobial susceptibilities were determined using the Kirby-Bauer disc diffusion method against seven classes of antimicrobial agents. A total of 440 staphylococci were isolated from 112 canine pets and their owners, 53.4% were from canine pets and 46.6% were from owners. Twenty-four species were detected, of which, most isolates (32.5%) belonged to the Staphylococcus intermedius group (SIG). S. sciuri was the most common species of coagulase-negative staphylococci (CoNS) comprising 22.3% of all isolates. Antimicrobial resistance was highest against commonly used antimicrobials, such as penicillin (51.4%), tetracycline (26.1%) and trimethoprim/sulfamethoxazole (18.6%). These antimicrobials also comprised the most common multidrug resistance (MDR) combination. Overall, 19.1% of isolates displayed multidrug resistance. No methicillin-resistant Staphylococcus aureus (MRSA) isolates were detected. However, methicillin resistance was detected in 13.3% and 15.1% of coagulase-positive staphylococci (CoPS) and the CoNS+CoVS (combined CoNS and coagulase-variable staphylococci) group respectively. The presence of methicillin-resistant staphylococci is worrisome because there is the potential for the transfer of these strains between dogs and humans. These strains may act as a reservoir of resistance genes.

Prevalence and antimicrobial resistance of Staphylococcus species isolated from cats and dogs

Background:

Methicillin-resistant staphylococci (MRS) are an emerging global problem with serious public health concern.

Aims:

This study investigated the prevalence and antimicrobial susceptibility of commensal Staphylococcus species isolated from healthy and clinical cats and dogs.

Methods:

Nasal swab samples were collected from animals and processed using selective and semi-selective mediums. Presumptive isolates were subjected to biochemical testing and analyzed using the Phoenix automated identification and susceptibility testing system. PCRs protocols were used to screen for mecA and pvl genes.

Results:

In total, 151 pets (103 cats and 48 dogs) were enrolled, of which 14 dogs (29%) and 24 cats (23%) were colonized with various Staphylococcus species mainly originated from healthy animals. A total of 38 staphylococci isolates were collected and distributed between 24 coagulase-negative and 14 coagulase-positive staphylococci. Only 13 staphylococci strains were identified as MRS, out of which only five isolates expressed that the mecA gene exclusively originated from healthy pets.

Conclusion:

This is the first study reporting the prevalence and colonization status of staphylococci species and MRS strains isolated from cats and dogs in Libya. The study reports important information of medical and clinical importance on antimicrobial and multidrug resistance of different staphylococci strains, particularly the coagulase negative species.

Diversity of methicillin-resistant staphylococci among wild Lepus granatensis: first detection of mecA-MRSA in hares

MRSA in humans, pets and livestock have been widely investigated, nevertheless, there is still little information of MRSA in wild animals. Therefore, this study aimed to investigate the occurrence and antimicrobial resistance profiles of methicillin-resistant staphylococci (MRS) in wild Iberian hares and to characterize their genetic lineages. Samples from 83 wild hares (Lepus granatensis) were collected during the hunting season. Isolation of MRS was accomplish using Oxacillin Resistant Screening Agar medium with 2 mg/L of oxacillin. The susceptibility of the isolates was tested by the Kirby-Bauer disc diffusion method. The presence of resistance and virulence genes was studied by PCR. S. aureus strains were further characterized by multilocus sequence typing, agr, spa and SCCmec typing. From the 83 samples, 12 (14.45%) coagulase-negative staphylococci and 3 (3.6%) MRSA strains were isolated. Nine coagulase-negative isolates showed resistance to at least one antibiotic. One MRSA isolate showed a multidrug-resistant profile with resistances to ß-lactams, aminoglycosides, macrolides and lincosamides. All MRSA strains were ascribed to ST2855, t1190 and SCCmec type III. The frequency of MRSA strains in wild hares was low, nevertheless, the presence of MRSA in game animals is considered a public health problem and may represent a route of transmission between animals and humans.

Commensal Staphylococci Including Methicillin-Resistant Staphylococcus aureus from Dogs and Cats in Remote New South Wales, Australia

Staphylococci are important opportunistic pathogens in human and veterinary medicine in addition to being part of the normal flora of the skin and mucous membranes of mammals and birds. The rise of antimicrobial resistance amongst staphylococci warrants closer investigation of the diversity of skin commensal organisms-including coagulase-negative staphylococci (CoNS)-due to their potential as a source of resistance genes. This study is aimed at characterising the commensal staphylococci-including methicillin-resistant Staphylococcus species (spp.)-from mucocutaneous sites of dogs and cats from remote New South Wales (NSW), Australia. Pet dogs and cats were recruited from participants in a community companion animal health programme in six communities in western NSW. Three swabs were collected from each animal (anterior nares, oropharynx, and perineum) and from skin lesions or wounds if present and cultured on selective media for Staphylococcus spp. In total, 383 pets (303 dogs, 80 cats) were enrolled. Staphylococcus spp. were isolated from 67.3% of dogs and 73.8% of cats (494 isolates). The diversity of CoNS was high (20 species) whilst only three coagulase-positive spp. were isolated (S. pseudintermedius, S. aureus, S. intermedius). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage in dogs was high (2.6%) relative to other studies but was only a small proportion of overall commensal staphylococci. No cats carried MRSA and no MRSP was isolated from either species. Dogs were significantly more likely to carry coagulase-positive staphylococci than cats (P < 0.001). Amongst dogs, males and those with skin lesions were more likely to carry S. pseudintermedius. This study highlights important differences in the diversity and patterns of carriage of commensal staphylococci between dogs and cats in remote NSW, Australia.

Dogs as reservoir of methicillin resistant coagulase negative staphylococci strains - A possible neglected risk

The antibiotic resistance among coagulase - negative Staphylococcus (CoNS) species towards methicillin is rarely reported in veterinary medicine. Under the aspect/concept of One Health, those strains pose a risk to human health due to the presence in canine pets where the transfer of resistant genetic markers might occur to other staphylococci species. The aim of this study was to investigate the antimicrobial resistance pattern among Coagulase Negative Staphylococci (CoNS) isolated from asymptomatic dogs and those affected by topic infections. Swabs from 254 dogs were first seeded in Mannitol Salt Agar. Species identification was conducted by Matrix Assisted Laser Desorption ionization - time of flight (MALDI-TOF ms) as previously described. The susceptibility test was performed by disk diffusion according to CLSI standards. Detection of mecA gene was performed. CoNS could be recovered from both groups of dogs and an alarming presence of methicillin-resistant coagulase negative staphylococci (MRCoNS) was confirmed, in 10.2% (17/166) of the samples. Eight of those methicillin resistant strains were isolated from asymptomatic dogs whereas nine were present in dogs affected by pyoderma and otitis externa.

Clonally Diverse Methicillin and Multidrug Resistant Coagulase Negative Staphylococci Are Ubiquitous and Pose Transfer Ability Between Pets and Their Owners

Sixty-eight owners and 66 pets, from 43 unrelated pet-owning households were screened for methicillin-resistant coagulase negative staphylococci (MRCoNS), potential cases of MRCoNS interspecies transmission (IT), and persistence. MRCoNS isolates were identified by microbiological and molecular tests. MLST-based phylogenetic analysis was performed in Staphylococcus epidermidis isolates. Antimicrobial susceptibility was evaluated using phenotypic and molecular methods. SCCmec type and the presence of biofilm-related ica locus was PCR-tested. Isolates suspected for MRCoNS IT cases were subjected to SmaI-PFGE analysis and individuals from positive households were followed-up for 1 year for carriage dynamics (every 3 months, T0-T4). Nineteen MRCoNS isolates from owners (27.9%) and 12 from pets (16.7%) were detected, coming from 20 households (46.5%). S. epidermidis was predominant (90 and 67% of human and animal strains, respectively), showing high phylogenetic diversity (16 STs among 24 strains). Methicillin-resistant S. epidermidis (MRSE) strains belonged to CC5 (75%), CC11 (12.5%), singleton S556 (8.3%), and S560 (4.17%). Significant host-associated differences were observed for resistance to aminoglycosides, co-trimoxazole, chloramphenicol (higher in animal isolates) and tetracycline (higher among human strains). Multidrug resistance (MDR) was common (68.4%) and associated with human strains. Great diversity of ccr and mec complexes were detected, most strains being non-typeable, followed by SCCmecIV and V. Over one third of isolates (most from owners), carried the ica locus, all MRSE CC5. Two sporadic IT cases (T0) were identified in owners and dogs from two households (4.7%), with diverse interspecies-exchanged clones detected along the sampling year, especially in dogs. A comparative analysis of all MRCoNS, with all nasal coagulase positive staphylococci (CoPS) recovered from the same individuals at T0, revealed that CoPS alone was predominant in owners and pets, followed by co-carriage of CoPS and MRCoNS in owners but single MRCoNS in pets. Statistical analyses revealed that owners are more prone to co-carriage and that co-existence of IT cases and co-carriage are positively interrelated. MRCoNS from healthy owners and their pets are genetically heterogeneous MDR strains that are spread in the community. Therefore, pets also contribute to the dissemination of successful human clones. Owner-pet inhabitancy increases the risk for staphylococcal temporal concomitance with its subsequent risk for bacterial infection and genetic exchange.

High diversity of coagulase negative staphylococci species in wild boars, with low antimicrobial resistance rates but detection of relevant resistance genes

This work was focused to determine the prevalence and the species diversity of coagulase-negative staphylococci (CoNS) in wild boars, and to study their antimicrobial resistance phenotype and genotype. Nasal samples of 371 wild boars from six Spanish regions were collected for CoNS recovery. The identification was performed by MALDI-TOF mass-spectrometry. Antimicrobial susceptibility for eight antimicrobial agents was studied by disc-diffusion method and the presence of 31 antimicrobial resistance genes by PCR. CoNS were detected in nasal samples of 136/371 animals tested (36.6%), and 161 isolates were obtained (1-3/animal); a high diversity of species was found (n = 17), with predominance of S. sciuri (n = 64), S. xylosus (n = 21) and S. chromogenes (n = 17). Among CoNS isolates, 22.4% showed resistance to at least one antimicrobial tested. Tetracycline-resistance phenotype was the most frequently detected (10.5%), generally mediated by tet(K) gene [associated or not with tet(L)]. Other relevant resistance genes were identified including unusual ones [mecA, erm(B), erm(F), mphC, erm(43), msr(A)/msr(B), lnu(A), dfrG, fexA, and cat_pC221]. This is the first study in which CoNS isolates from wild boars are analysed. The knowledge of antimicrobial phenotype and genotype of CoNS in natural ecosystems is highly important since these staphylococcal species can act as vectors of relevant antimicrobial resistance mechanisms.

Prevalence, toxigenic potential and antimicrobial susceptibility profile of Staphylococcus isolated from ready-to-eat meats

Aim

An epidemiological surveillance for Staphylococci contamination of ready-to-eat (RTE) meats from Enugu State, Nigeria, was carried out to determine the prevalence, species distribution, toxigenic potential and antimicrobial susceptibility profile of the organisms and hence the microbiological and toxicological safety of the meats.

Materials and Methods

Isolation and phenotypic Staphylococcus detection were done according to standard microbiological methods. Phenotypic resistance to 17 commonly used antimicrobial agents was determined by disc diffusion method. Molecular characterization of the isolates to species level and detection of selected toxigenic and antimicrobial-resistance genes were done by PCR methods.

Results

Twenty-four (9.4%) of the 255 meat samples investigated were contaminated with Staphylococcus species. Twenty-four Staphylococcus isolates belonging to six species of coagulase-negative Staphylococcus (CoNS) were identified. Four (16.7%) isolates harbored genes coding for exfoliative toxin-A. Ten (41.7%) isolates were multidrug resistant, while mecA, tetK, mphC, ermT and ermC were the antimicrobial-resistance genes detected in the isolates. Meat samples sourced from motor parks (16.7%) and open markets (8.5%) were the most contaminated.

Conclusion

9.4% of RTE meats sampled were contaminated with toxigenic and multidrug resistance CoNS. Beef was the most contaminated RTE meat type and harbored all the toxigenic and most of the antibiotic-resistant genes detected. Meat samples from motor parks had the highest staphylococcal contamination (16.7%), while those from mechanic village had the least (2.4%). Majority (79.2%) of the isolates were not susceptible to fusidic acid but none exhibited antimicrobial-resistance to chloramphenicol, ciprofloxacin, linezolid or teicoplanin. Food safety authorities in the study area should work proactively to massively improve the hygienic practices of meat vendors; in order to limit staphylococcal contamination of RTE meats and the associated public health problems.

Detection and characterization of methicillin-resistant and susceptible coagulase-negative staphylococci in milk from cows with clinical mastitis in Tunisia

OBJECTIVES

This study investigated prevalence of methicillin-resistant (MR) and methicillin-susceptible (MS) coagulase-negative staphylococci (CNS) and the implicated mechanisms of resistance and virulence in milk of mastitis cows. In addition, the presence of SCCmec type was analyzed in MR Staphylococcus epidermidis (MRSE).

RESULTS

Three hundred milk samples from cows with clinical mastitis were obtained from 30 dairy farms in different regions of Tunisia. Sixty-eight of the 300 tested samples contained CNS strains. Various CNS species were identified, with Staphylococcus xylosus being the most frequently found (40%) followed by Staphylococcus warneri (12%). The mecA gene was present in 14 of 20 MR-CNS isolates. All of them were lacking the mecC gene. The SCCmecIVa was identified in four MRSE isolates. Most of CNS isolates showed penicillin resistance (70.6%) and 58.3% of them carried the blaZ gene. MR-CNS isolates (n = 20) showed resistance to erythromycin, tetracycline and trimethoprim-sulfametoxazole harboring different resistance genes such us erm(B), erm(T), erm(C), mph(C) or msr(A), tet(K) and dfr(A). However, a lower percentage of resistance was observed among 48 MS-CNS isolates: erythromycin (8.3%), tetracycline (6.2%), streptomycin (6.2%), clindamycin (6.2%), and trimethoprim-sulfametoxazole (2%). The Inu(B) gene was detected in one Staphylococcus xylosus strain that showed clindamycin resistance. The virulence gene tsst-1 was observed in one MR-CNS strain.

DISCUSSION

Coagulase-negative staphylococci containing a diversity of antimicrobial resistance genes are frequently detected in milk of mastitis cows. This fact emphasizes the importance of identifying CNS when an intramammary infection is present because of the potential risk of lateral transfer of resistant genes among staphylococcal species and other pathogenic bacteria.

Temporal trends and predictors of antimicrobial resistance among Staphylococcus spp. isolated from canine specimens submitted to a diagnostic laboratory

Background

Resistance to commonly used antimicrobials is a growing concern in both human and veterinary medicine. Understanding the temporal changes in the burden of the problem and identifying its determinants is important for guiding control efforts. Therefore, the objective of this study was to investigate temporal patterns and predictors of antimicrobial resistance among Staphylococcus spp. isolated from canine specimens submitted to the University of Kentucky Veterinary Diagnostic Laboratory (UKVDL) between 1993 and 2009.

Methods

Retrospective data of 4,972 Staphylococcus isolates assessed for antimicrobial susceptibility using the disk diffusion method at the UKVDL between 1993 and 2009 were included in the study. Temporal trends were assessed for each antimicrobial using the Cochran-Armitage trend test. Logistic regression models were used to investigate predictors of antimicrobial resistance (AMR) and multidrug resistance (MDR).

Results

A total of 68.2% (3,388/4,972) Staphylococcus isolates were S. intermedius group (SIG), 18.2% (907/4,972) were coagulase-negative staphylococci (CoNS), 7.6% (375/4,972) were S. aureus, 5.8% (290/4,972) were S. hyicus, and S. schleiferi subsp. coagulans comprised 0.2% (12/4,972) of the isolates. The overall percentage of AMR and MDR were 77.2% and 25.6%, respectively. The highest levels of AMR were seen in CoNS (81.3%; 737/907), S. aureus (80.5%; 302/375), and SIG (77.6%; 2,629/3388). The lowest levels of AMR were observed in S. hyicus (57.9%; 168/290) and S. schleiferi subsp. coagulans (33.3%; 4/12). Overall, AMR and MDR showed significant (p<0.001) decreasing temporal trends. Significant temporal trends (both increasing and decreasing) were observed among 12 of the 16 antimicrobials covering 6 of the 9 drug classes assessed. Thus, significant increasing temporal trends in resistance were observed to β-lactams (p<0.001) (oxacillin, amoxicillin-clavulanate, cephalothin, and penicillin (p = 0.024)), aminoglycosides (p<0.001) (gentamicin, and neomycin), bacitracin (p<0.001), and enrofloxacin (p<0.001). In contrast, sulfonamide (p<0.001) (sulfadiazin) and tetracycline (p = 0.010) resistant isolates showed significant decreasing temporal trends in AMR. Staphylococcus spp., geographic region, and specimen source were significant predictors of both AMR and MDR.

Conclusions

Although not unexpected nor alarming, the high levels of AMR to a number of antimicrobial agents and the increasing temporal trends are concerning. Therefore, continued monitoring of AMR among Staphylococcus spp. is warranted. Future studies will need to identify local factors responsible for the observed geographic differences in risk of both AMR and MDR.

Nasal carriage of methicillin-resistant coagulase-negative staphylococci in healthy humans is associated with occupational pig contact in a dose-response manner

This study aimed to explore the association between occupational pig contact and human methicillin-resistant coagulase-negative staphylococci (MRCoNS) carriage. We conducted a cross-sectional study of pig exposed participants and controls in Guangdong, China, using a multi-stage sampling design. Participants provided a nasal swab for MRCoNS analysis and resulting isolates were tested for antibiotic susceptibility. The dose-response relation was examined using log binomial regression or Poisson regression models. The adjusted prevalence of MRCoNS carriage in pig exposed participants was 1.67 times (95% CI: 1.32-2.11) higher than in controls. The adjusted average number of resistance to different antibiotic classes of MRCoNS isolates from pig exposed participants was 1.67 times (95% CI: 1.46-1.91) higher than those from controls. Notably, we found the frequency and duration of occupational pig contact was associated with increased prevalence and increased number of resistance to different antibiotic classes of MRCoNS in a dose-response manner. When examining these relations by MRCoNS species, there was still evidence of similar exposure-response relations. Additionally, the proportion of tetracycline-resistant and tet(M)-containing MRCoNS isolates was significantly higher in pig exposed participants than in controls. These findings suggested a potential transmission of MRCoNS from livestock to humans by occupational livestock contact, and the presence of phenotypic and genotypic tetracycline resistance may aid in the differentiation of animal origins of MRCoNS isolates.

Prevalence of the Antibiotic Resistance Genes in Coagulase-Positive-and Negative-Staphylococcus in Chicken Meat Retailed to Consumers

The use of antibiotics in farm management (growing crops and raising animals) has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB) and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG) to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mecA and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-resistant coagulase-negative staphylococci (MRCNS) and methicillin-susceptible coagulase-negative staphylococci (MSCNS) isolated from the retail trade of ready-to-eat raw chicken meat samples collected during 1 year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim, and vancomycin) and their endorsement of the quinolone resistance determining region, mecA and cfr genes. The isolation results revealed 50 isolates, CPS (14) and CNS (36), representing ten species (S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius, and S. lentus). Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mecA gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides, and streptogramin B [MLS(_B)] in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance-determining-regions, the identification of MRSA and MR-CNS from retail chicken meat in Egypt. In addition, these isolates might indicate the promulgation of methicillin, oxacillin and vancomycin resistance in the community and imply food safety hazards.

Staphylococcus simulans associated with endocarditis in broiler chickens

This report suggests a strong association between coagulase-negative Staphylococcus simulans and endocarditis in broiler chickens of a single flock. Clinical signs included increased mortality and lameness, and some dead chickens were found on their backs. Lesions included cauliflower-like, fibrinous vegetative lesions on the left atrioventricular valve; cream-coloured, necrotic foci of varying size in the liver; and necrosis of the femoral head. Histopathological examination of the heart revealed multifocal conglomerates of bacterial colonies attached to the valvular endocardium, threads of fibrin, and inflammatory cells with the presence of heterophils. S. simulans strains were first identified by API ID32, and then confirmed with Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry and by partial sequencing of the rpoB and dnaJ genes. These bacteria were resistant to methicillin but sensitive to vancomycin and characterized by slime production and protease activity.

Phenotypic and genotypic detection of methicillin-resistant Staphylococcus aureus in hunting dogs in Maiduguri metropolitan, Borno State, Nigeria

Aim:

To determine the presence of MRSA in hunting dogs in Maiduguri metropolitan.

Materials and Methods:

Phenotypic methods used includes microscopic technique, colony morphology study, catalase-coagulase tests, and the use of mannitol salt agar test, oxacillin resistance screening agar base, and antibiotic susceptibility testing methods. Genotypic approach was used for deoxyribonucleic acid extraction, and the presence of nuc and mecA gene was detected using polymerase chain reaction (PCR) techniques.

Results:

Examination of 416 swab samples from nasal and perineal region of dogs revealed a total of 79.5% of S. aureus, where 62.5% of the isolates were MRSA. Molecular analysis revealed that 7nuc genes specific for S. aureus from 20 presumptive MRSA assay were all mecA PCR negative. The isolates were sensitive to gentamicin and ciprofloxacin but proved resistant to cefoxitin and oxacillin.

Conclusion:

High isolation rate of MRSA was found in hunting dogs. Significant level (p<0.05) of MRSA was isolated in the nasal cavity of hunting dogs than its perineum. Only nuc genes were detected from the MRSA isolates.

Characterization of mannitol-fermenting methicillin-resistant staphylococci isolated from pigs in Nigeria

This study was conducted to determine the species distribution, antimicrobial resistance pheno- and genotypes and virulence traits of mannitol-positive methicillin-resistant staphylococci (MRS) isolated from pigs in Nsukka agricultural zone, Nigeria. Twenty mannitol-positive methicillin-resistant coagulase-negative staphylococcal (MRCoNS) strains harboring the mecA gene were detected among the 64 Staphylococcus isolates from 291 pigs. A total of 4 species were identified among the MRCoNS isolates, namely, Staphylococcus sciuri (10 strains), Staphylococcus lentus (6 strains), Staphylococcus cohnii (3 strains) and Staphylococcus haemolyticus (one strain). All MRCoNS isolates were multidrug-resistant. In addition to β-lactams, the strains were resistant to fusidic acid (85%), tetracycline (75%), streptomycin (65%), ciprofloxacin (65%), and trimethoprim/sulphamethoxazole (60%). In addition to the mecA and blaZ genes, other antimicrobial resistance genes detected were tet(K), tet(M), tet(L), erm(B), erm(C), aacA-aphD, aphA3, str, dfrK, dfrG, cat pC221, and cat pC223. Thirteen isolates were found to be ciprofloxacin-resistant, and all harbored a Ser84Leu mutation within the QRDR of the GyrA protein, with 3 isolates showing 2 extra substitutions, Ser98Ile and Arg100Lys (one strain) and Glu88Asp and Asp96Thr (2 strains). A phylogenetic tree of the QRDR nucleotide sequences in the gyrA gene revealed a high nucleotide diversity, with several major clusters not associated with the bacterial species. Our study highlights the possibility of transfer of mecA and other antimicrobial resistance genes from MRCoNS to pathogenic bacteria, which is a serious public health and veterinary concern.

Prevalence, species distribution and antimicrobial resistance patterns of methicillin-resistant staphylococci in Lithuanian pet animals

Background

The bacterial genus Staphylococcus consists of many species that causes infections in pet animals. Antimicrobial resistant staphylococci cause infections that are difficult to treat and they are important from the point of one health perspective. The aim of this study was to determine the prevalence of methicillin-resistant Staphylococcus (MRS) species, including methicillin-resistant S. aureus (MRSA) in diseased pet animals (Group A) and kennel dogs (Group B) in Lithuania and to characterize the isolates according to their antimicrobial resistance.

Results

Twenty-one MRS isolates were obtained from 395 clinical samples (5.3 %; CI 95 % 3.5-8.0) of Group A animals. Sixteen, four and one isolates were from dogs, cats and a pet rabbit, respectively. The mecA gene was present in 20 isolates, whereas one isolate was positive for the mecC gene. Twenty-one MRS isolates (20.0 %; CI 95 % 13.5-28.6) were obtained from the vagina of female dogs (n = 105) (Group B). All isolates carried the mecA gene. Twelve MRS species were isolated of which S. pseudintermedius was the most common (18/42) followed by S. haemolyticus (8/42) and S. lentus (4/42). MRSA was not found. All MRS strains were susceptible to vancomycin, linezolid, daptomycin and quinupristin/dalfopristin. Resistance to tetracycline (16/21), clindamycin (15/21) and erythromycin (14/21) was the most common types of resistance in Group A animals. Three isolates also demonstrated resistance to rifampin. Resistance toward gentamicin (16/21), ciprofloxacin (15/21), macrolides (15/21) and tetracycline (12/21) was the most common in kennel dogs (Group B). The most common genes encoding resistance to antimicrobials (excluding beta-lactams) in isolates from Group A pets were tetK (21/42), aph(3′)-IIIa (11/42) and aac(6')-Ie-aph(2'')-Ia (9/42).

Conclusions

A wide range of MRS species were found in pet animals in Lithuania. MRSA was not found.

Diversity of antimicrobial resistance and virulence genes in methicillin-resistant non-Staphylococcus aureus staphylococci from veal calves

In this study we determined whether methicillin-resistant non-Staphylococcus aureus (MRNAS) from veal calves may be a potential reservoir of antimicrobial-resistance and virulence genes. Fifty-eight MRNAS were studied by means of DNA-microarray and PCR for detection of antimicrobial resistance and virulence genes. The isolates carried a variety of antimicrobial-resistance genes [aacA-aphD, aadD, aph3, aadE, sat, spc, ampA, erm(A), erm(B), erm(C), erm(F), erm(T), lnu(A), msr(A)-msr(B), vga(A), mph(C), tet(K), tet(M), tet(L), cat, fexA, dfrA, dfrD, dfrG, dfrK, cfr, fusB, fosB, qacA, qacC, merA-merB]. Some isolates carried resistance genes without showing the corresponding resistance phenotype. Most MRNAS carried typical S. aureus virulence factors like proteases (sspP) and enterotoxins (seg) genes. Most Staphylococcus epidermidis isolates carried the arginine catabolic element, and nearly 40% of the Staphylococcus sciuri isolates carried leukocidins, and/or fibronectin-binding protein genes. MRNAS were highly multi-resistant and represent an important reservoir of antimicrobial resistance and virulence genes.