Prevalence and Risk Factors of Colonization with Staphylococcus aureus in Healthy Pet Cats Kept in the City Households

Occurrence of antimicrobial-resistant Staphylococcus aureus in a Brazilian veterinary hospital environment

Antimicrobial resistance is a threat to public health. The emergence of antibiotic-resistant Staphylococcus aureus represents a priority for the implementation of preventive measures. The objective was to isolate S. aureus in humans, animals, and animal health care environment, and to characterize the genotypic and phenotypic profile of antimicrobial resistance in these isolates. We isolated S. aureus from staff, animals, and environment of a veterinary hospital, and identified their antimicrobial resistance profiles. Samples were collected from 20 humans, 13 animals, 14 surfaces, 8 mobile phones, and 7 veterinarians' stethoscopes by using sterile swabs. S. aureus was isolated by culturing on mannitol salt agar and preliminary identification was done by Gram staining and catalase test. Subsequently, a polymerase chain reaction was performed for species confirmation and investigating their antimicrobial-resistant genotypic profiles. Phenotypic profiles of resistant isolates were determined using the disk-diffusion technique. Ten S. aureus isolates were recovered from 5/20 humans (25%), it was also recovered from 2/13 animals (15.38%), including 1 dog and 1 cat, and from 1/14 of surfaces (7.14%). The oxacillin-susceptible mecA-positive Staphylococcus aureus phenotype was identified in a feline. Most of the isolates carried at least two resistance genes of different antimicrobial classes, with 90% (9/10) presenting the gene blaZ, with 10% (1/10) presenting the gene mecA, 20% (2/10) presenting tet38, 10% (1/10) presenting tetM, 90% (9/10) presenting norA, 50% (5/10) presenting norC, 10% (1/10) presenting ermA, and 60% (6/10) presenting ermB. In antibiograms, resistance to penicillin was identified in all the isolates, resistance to erythromycin was identified in 80% (8/10), and all the isolate's resistance to erythromycin presented erythromycin-induced resistance to clindamycin. Antimicrobial resistance in the veterinary hospital requires attention due to the risk of interspecies transmission, gene transfer between bacteria that colonize companion animals and humans and, can make antimicrobial therapy difficult.

Chromogenic culture media complements diagnostic cytology in the visual identification of pathogenic skin bacteria in dogs and cats

In dogs and cats, bacterial skin infections (pyoderma and otitis externa) are a common cause for visiting the veterinary clinic. The most frequent skin pathogens are Staphylococcus pseudintermedius, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, often requiring different therapeutic antibiotic protocols. Unfavorably, existing diagnostics based on cytology cannot reveal bacterial species but only bacterial shapes such as cocci or rods. This microscopic limitation could be overcome by clinical translation of affordable chromogenic media, which enable species identification based on bacterial colonies growing in different colors and sizes. In this study, we determined how well inexperienced general veterinary clinicians identified bacterial pathogens from the skin and ears on two commercial (Chromatic™ MH and Flexicult® Vet) and one custom-made Mueller Hinton agar-based chromogenic medium. For this purpose, four veterinarians evaluated 100 unique samples representing 10 bacterial species. On average, clinicians correctly identified between 72.1 and 86.3% of bacterial species. Colony colors developed quickly on the Chromatic™ MH medium, leading to the highest 81.6% identification accuracy after 24 h incubation. However, Flexicult® Vet exhibited the highest accuracy of 86.3% after prolonged 48 h incubation. Evaluators easily recognized bacteria displaying uniquely colored colonies like green-brown Pseudomonas aeruginosa, blue Enterococcus faecalis, orange-brown Proteus spp., and red Escherichia coli. Oppositely, staphylococci shared uncharacteristically pale pink colonies causing misidentifications among the genus, deteriorating overall accuracy by around 10 percentage points (from 90.9%). Another reason for identification errors was the evaluators' inexperience, reflected in not recognizing colony size differences. For example, although Streptococcus canis exhibited the tiniest colonies, the species was frequently mistaken for other cocci. Finally, around 10% of errors were negligence-related slips due to unconsidered sample history. To conclude, the introduction of chromogenic media into veterinary clinics can significantly complement diagnostics in skin inflammations by identifying pathogen species in around 80% of cases. The extra information may help in therapeutic dilemmas on antibiotics and standard antimicrobial susceptibility testing. Additional personnel training and evaluation help by visuals, flowcharts, checklists, and, if necessary, microbiologists could further improve identification accuracy.

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.

Staphylococci isolated from cats in Italy with superficial pyoderma and allergic dermatitis: Characterisation of isolates and their resistance to antimicrobials

BACKGROUND

In cats, superficial pyoderma traditionally is considered rare and few reports are available. There is a particular lack of studies concerning Staphylococcus species associated with pyoderma in subjects affected by allergic skin diseases.

HYPOTHESIS/OBJECTIVES

(i) To evaluate the association between Staphylococcus spp. and superficial pyoderma in allergic cats and (ii) to characterise isolated staphylococci and analyse their antimicrobial resistance patterns.

ANIMALS

Forty-one cats with allergic dermatitis and superficial pyoderma in Italy.

MATERIALS AND METHODS

Skin swabs were cultured for the isolation of Staphylococcus spp. Species identification was performed by matrix-assisted laser desorption/ionisation time of flight mass spectrometry and 16S-rRNA sequencing. Staphylococcus aureus isolates were further characterised by staphylococcal protein A gene-typing. Antimicrobial susceptibility was performed by the disk diffusion method.

RESULTS

Staphylococci were isolated from 36/41 cats sampled and 39 different isolates were identified. Uneven distribution of staphylococcal species was observed among different body locations. The 39 isolates were S. aureus (n = 15), S. felis (n = 10), S. pseudintermedius (n = 8) and other staphylococci (n = 6). Eight different S. aureus spa-types associated with human clonal complexes were identified. Antimicrobial resistance was observed to penicillin (56.4%), tetracycline (46.2%), enrofloxacin (33.3%), erythromycin (28.2%), amikacin (25.6%), clindamycin (23.1%), marbofloxacin (15.4%), gentamicin (12.8%), trimethoprim-sulfamethoxazole (10.3%), chloramphenicol (7.7%) and cefoxitin/oxacillin (5.1%). Fifteen isolates (38.4%) were multidrug-resistant while meticillin resistance was associated only with S. pseudintermedius.

CONCLUSIONS AND CLINICAL RELEVANCE

These results confirm that S. aureus, S. pseudintermedius, and S. felis are frequently associated with superficial pyoderma in allergic cats. Semi-synthetic penicillins remain a suitable first-line treatment in this study, yet the high prevalence of antimicrobial resistant isolates suggests that antimicrobial susceptibility testing should be performed routinely.

Wild Animals Are Reservoirs and Sentinels of Staphylococcus aureus and MRSA Clones: A Problem with "One Health" Concern

Background: The availability of comprehensive data on the ecology and molecular epidemiology of Staphylococcus aureus/MRSA in wild animals is necessary to understand their relevance in the "One Health" domain. Objective: In this study, we determined the pooled prevalence of nasal, tracheal and/or oral (NTO) Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) carriage in wild animals, with a special focus on mecA and mecC genes as well as the frequency of MRSA and methicillin susceptible S. aureus (MSSA) of the lineages CC398 and CC130 in wild animals. Methodology: This systematic review was executed on cross-sectional studies that reported S. aureus and MRSA in the NTO cavities of wild animals distributed in four groups: non-human primates (NHP), wild mammals (WM, excluding rodents and NHP), wild birds (WB) and wild rodents (WR). Appropriate and eligible articles published (in English) between 1 January 2011 to 30 August 2021 were searched for from PubMed, Scopus, Google Scholar, SciElo and Web of Science. Results: Of the 33 eligible and analysed studies, the pooled prevalence of NTO S. aureus and MRSA carriage was 18.5% (range: 0-100%) and 2.1% (range: 0.0-63.9%), respectively. The pooled prevalence of S. aureus/MRSA in WM, NHP, WB and WR groups was 15.8/1.6, 32.9/2.0, 10.3/3.4 and 24.2/3.4%, respectively. The prevalence of mecC-MRSA among WM/NHP/WB/WR was 1.64/0.0/2.1/0.59%, respectively, representing 89.9/0.0/59.1/25.0% of total MRSA detected in these groups of animals.The MRSA-CC398 and MRSA-CC130 lineages were most prevalent in wild birds (0.64 and 2.07%, respectively); none of these lineages were reported in NHP studies. The MRSA-CC398 (mainly of spa-type t011, 53%), MRSA-CC130 (mainly of spa types t843 and t1535, 73%), MSSA-CC398 (spa-types t571, t1451, t6606 and t034) and MSSA-CC130 (spa types t843, t1535, t3625 and t3256) lineages were mostly reported. Conclusion: Although the global prevalence of MRSA is low in wild animals, mecC-mediated resistance was particularly prevalent among MRSA isolates, especially among WM and WB. Considering the genetic diversity of MRSA in wild animals, they need to be monitored for effective control of the spread of antimicrobial resistance.

Epidemiology of Staphylococcus pseudintermedius in cats in Poland

Staphylococcus pseudintermedius is a well-known coagulase-positive staphylococcus that is mainly associated with the asymptomatic colonization of the skin of pets and mucous membranes. Little is still known about the occurrence of S. pseudintermedius in cats. The current study aimed to characterize the isolates of S. pseudintermedius from sick and healthy cats. This was achieved by examining their antibiotic resistance properties, biofilm formation, and genotype differences. Six hundred and seventy-six cats were swabbed (595 healthy and 81 sick cats). Thirty-five distinct S. pseudintermedius isolates from 27 cats were isolated. The prevalence of S. pseudintermedius in healthy and sick cats was 2.49% and 7.61%, respectively. In comparison, MRSP (methicillin-resistant Staphylococcus pseudintermedius) prevalence was 0.12% and 2.98%, respectively. Cats were more frequently colonized with S. pseudintermedius when kept with dogs, regardless of their health condition, with this result being statistically significant. Multidrug resistance was detected in 50%, and 38.46% of S. pseudintermedius isolates from healthy and sick cats, respectively. In contrast, genetic multidrug resistance was detected in 59% and 46.15% cases, respectively. Seven from eight isolated MRSPs were multidrug-resistant. Multi-locus sequence typing (MLST) assigned isolates to 19 types, of which 16 types submitted for the first time to the PubMLST database. The most frequently detected STs (sequence types) were 551 and 71. ST71 and ST551 were mainly isolated from cats with clinical signs of infection. All were MRSPs, regardless of cats’ health. These isolates were characterized with the most frequent antibiotic resistance at the phenotypic and genotypic level.

Epidemiology of the colonization and acquisition of methicillin-resistant staphylococci and vancomycin-resistant enterococci in dogs hospitalized in a clinic veterinary hospital in Spain

Antibiotic resistance is one of the biggest threats to human and animal health. Methicillin-resistant Staphylococcus spp. (MRS) and vancomycin-resistant Enterococcus spp. (VRE) are of increasing importance in hospital and/or nosocomial infections and represent a potential risk of transmission to humans from infected or colonized companion animals. Studies on the risk factors associated with colonization by multiresistant bacteria in animals are scarce. The present study aimed to estimate the prevalence and incidence of MRS and VRE in canine patients hospitalized in a veterinary hospital and to identify the risk factors for its acquisition and persistence. Nasal and perianal swabs were obtained from 72 dogs. Antimicrobial susceptibility assays and molecular detection of mecA and van genes were performed. A prevalence of 13.9% and incidence of 26.5% was observed in dogs colonized by MRS at hospital admission and release, respectively, higher values than those described in most veterinary studies. Thirty-five Staphylococcus isolates had mecA gene and showed higher resistance levels to most of the antimicrobials evaluated. Previous and concomitant use of antibiotics and corticosteroids has been associated with an increase in MRS colonization. The use of antibiotics in other animals living with the canine patients has also been identified as an associated factor, suggesting cross transmission. The presence of van-resistant genes from Enterococcus spp. was not detected. Pets should be considered possible vehicles of transmission and reservoirs for MRS bacteria and veterinary hospitals should be considered high-risk environments for the occurrence and spread of nosocomial infections and resistant bacteria.

Pathogenetic role of Staphylococcus aureus in purulent keratoconjunctivitis in cats

The research was carried out in the Department of Surgery and Obstetrics of Agricultural Animals of Dnipro State Agrarian and Economic University on clinically healthy outbred cats of different ages with purulent keratoconjunctivitis. Hematological, biochemical and immunological parameters were determined in the animals, and microbiological and virological research was conducted on them. According to the data obtained, more than half of cases of ophthalmopathology in cats were conjunctivitis and keratoconjunctivitis, and they were more often registered in the cold season. The main causes of eye diseases in the cats were mechanical injuries, coccal and chlamydial infection, allergy and development of disease against the background of primary lesions of the ears and paranasal sinuses. Among the detected microorganisms, the vast majority (81.9%) were staphylococci, including S. albus, S. aureus and S. epidermidis. All types of microorganisms except O-forms of Bacillus sp. exhibited high and medium sensitivity to antibiotics. Immunoblotting revealed polypeptides that responded to specific S. aureus antigens in samples of conjunctiva, cornea, intraocular fluid, and blood of cats suffering from purulent (staphylococcal) keratoconjunctivitis. The highest antigen concentration was detected in the cornea and conjunctiva. In the absence of expressive shifts of the investigated hematological and biochemical parameters, the dynamics of immunological markers were shown by a significant increase in the content of immunoglobulins and circulating immune complexes, as well as by a distinct activation of the complement system by the classical route. The results showed a clear gradual activation of phagocytosis, namely: the number of phagocytic neutrophils increased, reaching its maximum value by the seventh day of development of purulent keratoconjunctivitis. The phagocytic index in the first three days of observation tended to decrease, and by the seventh day it had already significantly exceeded the initial value. Despite the ambiguous dynamics of the phagocytic index, in the course of the development of the inflammatory process in the blood of sick cats, we observed a clear increase in the index of complete phagocytosis. Thus, the development of purulent keratoconjunctivitis in cats occurs against the background of clear cellular and humoral responses to the infectious agent.

Distribution of Toxinogenic Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus from Different Ecological Niches in Algeria

The diffusion of Panton-Valentine leukocidin (PVL)-positive methicillin-resistant S. aureus (MRSA) is a health problem in Algeria. The objectives of the study were to investigate the global distribution of methicillin-susceptible S. aureus (MSSA) and MRSA isolates in different ecological niches in this country. In total, 2246 samples were collected from humans, livestock, wild animals, pets, food products and the aquatic environment, from 12 Algerian provinces. A total of 312 S. aureus were detected from 2446 samples (12.7%) in the screened niches. We observed the emergence of toxinogenic S. aureus representing 41% of the isolates. Among them, we noted the diffusion of ST80-IV CA-MRSA PVL + strains isolated in human, animals, and food and genetic diversity of MSSA PVL + isolates. This study suggests an alarming dissemination of MRSA-ST80 PVL + in both human and extra-human sources in Algeria. Moreover, MSSA may become a permanent reservoir of the PVL genes necessary for human infections.

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.

Characterization, distribution, antimicrobial resistance and resistance risk factors in staphylococci isolated from cats from 2001 to 2014

Relatively few studies have been published describing the patterns of staphylococcal isolation and antimicrobial resistance over time in cats. The objective of this retrospective study was to determine the frequency, location, characteristics and antimicrobial resistance profiles of staphylococci isolated by the Louisiana Animal Disease Diagnostic Laboratory between the years 2001 and 2014. All feline staphylococcal isolates were classified phenotypically. Isolates corresponding to known or possibly pathogenic species (Staphylococcus intermedius group (SIG) and Staphylococcus aureus (SA)) as well as Staphylococcus epidermidis (SE) and non‐speciated coagulase‐negative staphylococci (CNS) were further evaluated to determine antimicrobial resistance patterns. A total of 519 staphylococci were isolated. The largest percentage of isolates was CNS, representing 39.3% of the total, while SIG, SE, SA and non‐speciated coagulase positive staphylococci (CPS) represented 18.1%, 10.2%, 8.3% and 7.3%, respectively. Methicillin resistance (MR) was identified in 57.1% of SA and 20.5% of SIG. Resistance to 3 or more antimicrobial classes (multidrug resistance; MDR) was demonstrated in 54.5% of SA and 23.9% of SIG. The prevalence of MDR increased over time in both SIG and SA, while the prevalence of MR increased over time in SIG. An increase in mean antimicrobial resistance score over time was seen in SIG. This study demonstrates a high and increasing prevalence of MDR in SIG and SA, as well as increasing prevalence of MR in SIG isolated from cats.

Methodologic considerations of household-level methicillin-resistant Staphylococcus aureus decolonization among persons living with HIV

BACKGROUND

People living with HIV (PLWH) have a higher prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization and likelihood of recurrent infection than the general population. Simultaneously treating MRSA-colonized household members may improve success with MRSA decolonization strategies. This article describes a pilot trial testing household-level MRSA decolonization and documents methodologic and pragmatic challenges of this approach.

METHODS

We conducted a randomized controlled trial of individual versus individual-plus-household MRSA decolonization to reduce recurrent MRSA. PLWH with a history of MRSA who are patients of an urban HIV clinic received a standard MRSA decolonization regimen. MRSA colonization at 6 months was the primary outcome.

RESULTS

One hundred sixty-six patients were referred for MRSA screening; 77 (46%) enrolled. Of those, 28 (36%) were colonized with MRSA and identified risk factors consistent with the published literature. Eighteen were randomized and 13 households completed the study.

CONCLUSIONS

This is the first study to report on a household-level MRSA decolonization among PLWH. Challenges included provider referral, HIV stigma, confidentiality concerns over enrolling households, and dynamic living situations. Although simultaneous household MRSA decolonization may reduce recolonization, recruitment and retention challenges specific to PLWH limit the ability to conduct household-level research. Efforts to minimize these barriers are needed to inform evidence-based practice.