Evaluating the antimicrobial and anti-biofilm activity of three synthetic antimicrobial Citropin analogs and their ability to fight against Staphylococcus aureus and Staphylococcus pseudintermedius.

AIMS: We developed three new analogs of the antimicrobial peptide (AMP) Citropin 1.1: DAN-1-13, AJP-1-1, and HHX-2-28, and tested their potential antimicrobial and anti-biofilm activities against S. aureus and S. pseudintermedius. Potential cytotoxic or hemolytic effects were determined using cultured human keratinocytes and erythrocytes to determine their safety. METHODS AND RESULTS: To assess the antimicrobial activity of each compound, minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined against methicillin-resistant and methicillin-susceptible strains of S. aureus and S. pseudintermedius. Activity against newly formed and mature biofilms was determined in two clinical isolates using spectrophotometry and scanning electron microscopy (SEM). All three compounds exhibited antimicrobial and bactericidal activity against all studied S. aureus and S. pseudintermedius strains, with MICs ranging from 4-32 µg ml- 1 and MBCs ranging from 8-128 µg ml- 1. Subinhibitory concentrations of all compounds also showed anti-biofilm activity in the two tested isolates. All compounds exhibited limited cytotoxic and hemolytic activity. CONCLUSION: Novel analogs of Citropin 1.1 exhibit anti-microbial and bactericidal activities against S. aureus and S. pseudintermedius isolates and inhibit the biofilm formation of these bacteria.

Biofilm formation by Staphylococcus pseudintermedius on titanium implants.

Osteomyelitis often involves Staphylococcus spp. as the isolated genus in domestic animal cases. Implant-related infections, frequently associated with biofilm-forming microorganisms like staphylococci species, necessitate careful material selection. This study assessed biofilm formation by Staphylococcus pseudintermedius on titanium nuts used in veterinary orthopaedic surgery. Biofilm quantification employed safranin staining and spectrophotometric measurement, while bacterial counts were determined in colony-forming units (CFU). Scanning Electron Microscopy (SEM) evaluated the biofilm morphology on the surface of titanium nuts. All samples had CFU counts. Absorbance values that evidence biofilm formation were observed in seven of the eight samples tested. SEM images revealed robust bacterial colonization, and significant extracellular polymeric substance production, and the negative control displayed surface irregularities on the nut. Whole genome sequencing revealed accessory Gene Regulator (agr) type III in six samples, agr IV and agr II in two each. Genes encoding hlb, luk-S, luk-F, siet, se_int, and the icaADCB operon were identified in all sequenced samples. Other exfoliative toxins were absent. Biofilm formation by S. pseudintermedius was detected in all samples, indicating the susceptibility of orthopaedic titanium alloys to adhesion and biofilm formation by veterinary species. The biofilm formation capacity raises concerns about potential post-surgical complications and associated costs.

Epidemiologic case investigation on the zoonotic transmission of Methicillin-resistant Staphylococcus pseudintermedius among dogs and their owners.

Dogs often carry methicillin-resistant Staphylococci asymptomatically. These bacteria are frequently linked to conditions such as canine pyoderma and otitis. Close interaction between dogs and humans can facilitate the exchange of resistant strains, particularly Methicillin-resistant Staphylococcus pseudintermedius (MRSP). This represents a public health issue, since these strains, in addition to occasionally causing infections in humans, can also serve as a source of resistance and virulence genes for strains of greater importance in human medicine, such as Staphylococcus aureus. Furthermore, MRSP strains are often multidrug resistant, which ends up compromising the treatment of infections. This study aimed to assess the potential transmission of Staphylococcus pseudintermedius among dogs and their owners. We examined a total of one hundred canine samples collected from cases of pyoderma and otitis to detect the presence of staphylococci. Simultaneously, we conducted evaluations on all dog owners. Staphylococci strains were identified using MALDI-TOF MS and PCR targeting the nuc gene. Methicillin resistance screening was also performed by detecting the mecA gene using PCR. Among the sampled dogs, 64 carried S. pseudintermedius. Nine were identified as MRSP. In six instances, dogs and their owners exhibited S. pseudintermedius. These samples underwent genome sequencing and were screened for antimicrobial resistance genes, SCCmec typing, MLST characterization, and Single Nucleotide Polymorphisms (SNP) analyses. The results of the phylogenetic analysis revealed that in three cases, dogs and owners had closely related isolates, suggesting interspecies transmission. Two of these cases involved MRSP and one MSSP. Moreover, in the two MRSP cases, the same SCCmec type (type V) was detected. Additionally, the sequence type was consistent across all three cases involving dogs and owners (MSSP ST2277, MRSP ST2282, and ST2286). These findings strongly indicate a transmission event. Since Staphylococcus pseudintermedius is primarily isolated from canine samples, it is plausible that dogs may have acted as a potential source. In the remaining three cases, despite identifying the same species in both samples, they had notable phylogenetic differences.

High prevalence of Panton-Valentine Leucocidin among Staphylococcus coagulans isolated from dogs in Rio de Janeiro.

AIMS: The purpose of this study was to characterize the capacity for biofilm formation, antimicrobial resistance rates, and search for genetic determinants of resistance and virulence in the species. METHODS AND RESULTS: Strains were collected from asymptomatic and infected dogs. Identification was conducted using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF), antimicrobial susceptibility using disk diffusion and PCR targeting mecA. Biofilm formation was evaluated on a microtiter plate assay. A total of 27 strains were selected for whole-genome sequencing. We identified 111 Staphylococcus coagulans. The highest number was obtained from infected dogs. The highest resistance rates were observed for penicillin, gentamicin, and ciprofloxacin/erythromycin. Twelve strains were characterized as resistant to methicillin. All isolates had the ability to form biofilm and were strong producers. Among Methicillin Resistant Staphylococcus coagulans (MRSC), SCCmec types IIIA, and Vc were identified. Acquired resistance genes, such as aac(6')-aph(2''), tet(K), blaZ, qacG, qacJ, and erm(C) were found. Different virulence genes were identified. Of note, Panton-Valentine Leucocidin was highly prevalent among the isolates. CONCLUSION: Staphylococcus coagulans had a high isolation rate among infected dogs and demonstrated significant resistance to commonly used antibiotics such as penicillin and gentamicin.

Sporothrix brasiliensis Infection Modulates Antimicrobial Peptides and Stress Management Gene Expression in the Invertebrate Biomodel Galleria mellonella.

Sporothrix brasiliensis is the most pathogenic species, responsible for the Brazilian cat-transmitted sporotrichosis hyperendemic. In this scenario, an investigation of the pathogen-host interaction can provide relevant information for future treatment strategies. To this end, the invertebrate Galleria mellonella has proven to be a suitable alternative for evaluating the virulence of pathogenic fungi, since the insect immune system is similar to the mammalian innate immune response. The aim of this work was to investigate phenotypic and molecular aspects of the immune response of G. mellonella throughout the S. brasiliensis infection. Hemocyte density and the evolution of the fungal load were evaluated. In parallel, RT-qPCR expression analysis of genes encoding antimicrobial peptides (Gallerimycin and Galiomycin) and stress management genes (C7 Contig 15362 and C8 Contig 19101) was conducted. The fungal load and hemocyte densities increased simultaneously and proportionally to the deleterious morphological events and larvae mortality. Gallerimycin, C7 Contig 15362 and C8 Contig 19101 genes were positively regulated (p < 0.05) at distinct moments of S. brasiliensis infection, characterizing a time-dependent and alternately modulated profile. Galiomycin gene expression remained unchanged. Our results contribute to the future proposal of potential alternative pathways for treating and consequently controlling S. brasiliensis zoonosis, a major public health issue in Latin America.

Investigation of antimicrobial susceptibility and genetic diversity among Staphylococcus pseudintermedius isolated from dogs in Rio de Janeiro.

Staphylococcus pseudintermedius is an opportunistic pathogen causing a variety of infections that are difficult to treat, especially because of the development of antimicrobial resistance. It has a clonal distribution around the world. To have a better understanding of the MRSP population, we search the presence of MRSP in colonized or infected dogs. Samples from 99 dogs with infections and 35 from asymptomatic dogs were collected. Isolates were identified by mass spectrometry and Multiplex-PCR. The mecA gene was confirmed by conventional PCR. MRSP strains were analyzed by whole-genome sequencing. 75 S. pseudintermedius were identified, most from infection cases. The species were isolated from 70 out of the 135 dogs. Penicillin and Trimethoprim/Sulfamethoxazole presented higher resistance rates. Forty-seven strains were classified as multi-drug resistant (MDR), and were more isolated from dogs with infection (P < 0.05). Eighteen samples were classified as MRSP, representing 24.0% of the population. Six of 16 MRSP sequenced samples belonged to the world spread clone ST71; others belonged to unknown clones. Most samples carried the SCCmec type IIIA. Twenty-one different genetic resistance determinants were found among MRPS strains. MRSP is circulating among infected and colonized dogs in Rio de Janeiro, Brazil.

Prevalence of Clostridioides difficile in dogs (Canis familiaris) with gastrointestinal disorders in Rio de Janeiro.

Clostridioides difficile infections (CDI) have a high morbidity and mortality rate and have always been considered a nosocomial disease. Nonetheless, the number of cases of community-acquired CDI is increasing, and new evidence suggests additional C. difficile reservoirs exist. Pathogenic C. difficile strains have been found in livestock, domestic animals, and meat, so a zoonotic transmission has been proposed. OBJECTIVE: The goal of this study was to isolate C. difficile strains in dogs at a veterinary clinic in Rio de Janeiro, Brazil, and characterize clinical and pathological findings associated with lower gastrointestinal tract disorders. METHODS: Fifty stool samples and biopsy fragments from dogs were obtained and cultured in the CDBA selective medium. All suggestive C. difficile colonies were confirmed by MALDI-TOF MS and PCR (tpi gene). Vancomycin, metronidazole, moxifloxacin, erythromycin, and rifampicin were tested for antibiotic susceptibility. Biofilm, motility assays, and a PCR for the toxins (tcdA, tcdB, and cdtB), as well as ribotyping, were also performed. RESULTS: Blood samples and colonic biopsy fragments were examined in C. difficile positive dogs. Ten animals (20%) tested positive for C. difficile by using stool samples, but not from biopsy fragments. Most C. difficile strains were toxigenic: six were A+B+ belonging to RT106; two were A+B+ belonging to RT014/020; and two were A-B- belonging to RT010. All strains were biofilm producers. In the motility test, 40% of strains were as motile as the positive control, CD630 (RT012). In the disc diffusion test, two strains (RT010) were resistant to erythromycin and metronidazole; and another to metronidazole (RT014/020). In terms of C. difficile clinicopathological correlations, no statistically significant morphological changes, such as pseudomembranous and "volcano" lesions, were observed. Regarding hematological data, dogs positive for C. difficile had leucopenia (p = 0.02) and lymphopenia (p = 0.03). There was a significant correlation between senility and the presence of C. difficile in the dogs studied (p = 0,02). CONCLUSIONS: Although C. difficile has not been linked to canine diarrheal disorders, it appears to be more common in dogs with intestinal dysfunctions. The isolation of ribotypes frequently involved in human CDI outbreaks around the world supports the theory of C. difficile zoonotic transmission.

Evaluation of changes in antimicrobial susceptibility in bacteria infecting children and their mothers in pediatric, neonatal-intensive care unit, and gynecology/obstetrics wards of a quaternary referral hospital during the COVID-19 pandemic.

The World Health Organization released a statement warning of increased risk for the incidence of multidrug resistant microorganisms and the absence of new drugs to control such infections soon. Since the beginning of the COVID-19 pandemic, the prescription of antimicrobial agents has increased and may have accelerated the emergence of multidrug resistant (MDR) bacteria. This study aimed to evaluate maternal and pediatric infections within a hospital from January 2019 to December 2021. An observational retrospective cohort study was performed at a quaternary referral hospital in a metropolitan area of Niteroi city, Rio de Janeiro state, Brazil. A total of 196 patients' medical records were analyzed. The data from 90 (45.9%) patients were collected before the SARS-CoV-2 pandemic, 29 (14.8%) from the 2020 pandemic period, and 77 (39.3%) from the 2021 pandemic period. A total of 256 microorganisms were identified during this period. Out of those, 101 (39.5%) were isolated in 2019, 51 (19.9%) in 2020, and 104 (40.6%) in 2021. Antimicrobial susceptibility tests were performed on 196 (76.6%) clinical isolates. The exact binomial test showed that the distribution of Gram-negative bacteria was predominant. The most common microorganism was Escherichia coli (23%; n = 45), followed by Staphylococcus aureus (17.9%, n = 35), Klebsiella pneumoniae (12.8%, n = 25), Enterococcus faecalis (7.7%, n = 15), Staphylococcus epidermidis (6.6%, n = 13) and Pseudomonas aeruginosa (5.6%, n = 11). Staphylococcus aureus was the predominant species among resistant bacteria. Among the antimicrobial agents tested, the following were resistant, presented on a descending scale: penicillin (72.7%, p = 0.001, Binomial test), oxacillin (68.3%, p = 0.006, Binomial test), ampicillin (64.3%, p = 0.003, Binomial test), and ampicillin/sulbactam (54.9%, p = 0.57, Binomial test). Infections with S. aureus were 3.1 times greater in pediatrics and maternal units than in other hospital wards. Despite the global reduction in the incidence of MRSA, we observed an increase in MDR S. aureus in this study. No changes were observed in the frequency of resistance profiles of the clinical isolates after the establishment of the global SARS-CoV-2 pandemic. More comprehensive studies are needed to understand the impact of the global SARS-CoV-2 pandemic on the resistance levels of bacteria associated with neonate and pediatric patients.

Ethyl acetate fractions of Myrciaria floribunda, Ocotea pulchella, and Ocotea notata exhibit promising in vitro activity against Sporothrix brasiliensis isolates with low susceptibility to itraconazole.

Sporothrix brasiliensis with low susceptibility isolates were described from the Brazilian zoonotic sporotrichosis hyperendemics. The aim of this work was to evaluate distinct fractions of Ocotea pulchella, Ocotea notata, Myrciaria floribunda, and Hypericum brasiliense plant extracts against itraconazole-sensitive and low susceptibility S. brasiliensis isolates. Crude extracts were tested against clinical isolates and the ATCC MYA4823 to determine the minimum inhibitory concentrations (MICs) and fungicidal or fungistatic activities (MFC). A high MICs and MFCs amplitude (1 - > 128 µg/mL) were obtained for seven extracts. The highest antimicrobial activities against sensitive S. brasiliensis were displayed by the ethyl acetate extracts of O. notata (MIC = 2-128 µg/mL) and M. floribunda (MIC = 1-8 µg/mL). A fungicidal effect was observed for all fraction extracts. Ocotea spp. and M. floribunda ethyl acetate extracts provide promising profiles against itraconazole-sensitive or low susceptibility S. brasiliensis. Future studies will determine if these extracts can contribute as alternative therapies to this neglected zoonosis.

Detection of the international lineage ST71 of methicillin-resistant Staphylococcus pseudintermedius in two cities in Rio de Janeiro State.

Staphylococcus pseudintermedius is the main coagulase-positive staphylococci associated with canine skin/soft tissue infections (SSTI), otitis externa, and surgical site infections. The international spread of an epidemic and multiresistant lineage of methicillin-resistant Staphylococcus pseudintermedius (MRSP), the so-called European clone-displaying sequence type (ST) 71-requires attention. The first isolation of an MRSP ST71 isolate in South America was reported in Rio de Janeiro city, in 2010; however, a limited number of canine isolates were analyzed. Thus, to have a better panel of the MRSP spread in this city, we were stimulated to continue this study and search for the presence of MRSP in 282 colonized or infected dogs in the city of Rio de Janeiro. Among the MRSP isolates collected (N = 17; 6.1%), the pulsed-field gel electrophoresis (PFGE) patterns were similar to those of European clone. All 17 isolates were classified as ST71 by multilocus sequence typing (MLST). In order to assess whether isolates of MRSP ST71 may have also spread to the Rio de Janeiro state countryside, we collected samples from 124 infected dogs in the city of Campos dos Goytacazes (232 km away from Rio de Janeiro city). Our data showed the presence of ST71 lineage in one isolate among three MRSP detected. S. pseudintermedius was isolated from 40.6% of the clinical samples (N = 165/406). A relatively high incidence of methicillin resistance, detected by a PCR-based method, was found in 12.1% of the S. pseudintermedius recovered from animals (N = 20/165). The resistance profile of these isolates was similar to that described for the international ST71 strains whose genomes are publicly available in the GenBank. The prospect of ST71 isolates being resistant to virtually all antimicrobials used in veterinary medicine is alarming and should be considered a central issue considering that MRSP ST71 spreads over large geographic distances and its transmission from animals to humans.

Characterizing biofilm formation of Staphylococcus pseudintermedius in different suture materials.

Staphylococcus pseudintermedius is the primary cause of pyoderma and surgical site infection (SSI) in dogs, and biofilm formation is the main reason for persistent SSI. The presence of biofilm in medical devices can directly impact treatment. Methicillin-resistant S. pseudintermedius (MRSP) emerged rapidly in companion animals, limiting treatment options. MRSP is a public health problem since zoonotic transmission can occur. The study seeks to evaluate biofilm formation capacity via Staphylococcus pseudintermedius collected from dogs affected by topical infections, in suture materials commonly used in companion animal surgery. We tested segments of four types of sutures. Biofilm production was measured by staining with safranin and colorimetric absorbance measurement. We calculated colony-forming units (CFUs) for each type of sutures and visualized biofilm via Scanning Electron Microscopy (SEM) images. The genes associated with biofilm formation (icaA and icaD) were identified using PCR. The colorimetric tests showed that the biofilm is most abundantly formed on the cotton sutures and polyglactin 910. The ability to form biofilm on polypropylene and nylon sutures has also been demonstrated, although at varying intensities. PCR revealed the presence of the two genes (icaA and icaD) in all the isolates. We used a positive control using a reference strain and negative control without bacteria for comparisons. Suture material allowing biofilm formation makes it difficult to prevent and treat surgical site infections. Therefore, it is important to know which suture thread is more susceptible to biofilm formation by bacteria to prevent possible secondary infections at surgical sites.

In vitro comparison between antimicrobial and antibiofilm effects of Green Propolis and Baccharis dracunculifolia against Staphylococcus pseudintermedius isolate.

Staphylococcus pseudintermedius is the leading cause of canine pyoderma. Honeybee products are common to treat this and other types of infections. High average annual population loss of bees has been observed. This study evaluated antibacterial and antibiofilm profile of Green Propolis and Baccharis dracunculifolia against S. pseudintermedius and the chemical similarities among both. Ethanolic extracts were produced and chemically characterized. The isolates were subjected to treatment with the extracts in both planktonic and sessile forms. Green propolis minimum inhibitory concentration (MIC) was 0.156 mg / mL, and minimum bactericidal concentration (MBC) was 0.312mg / mL. Baccharis dracunculifolia extract MIC and MBC was 0.312mg / mL and 2.5 mg / mL, respectivelly. Both extracts reduced SD55 formation of biofilm at minimum inhibitory concentration and at 1/8 minimum inhibitory concentration. The results observed in relation to ED99, were similar for both extracts. Besides that, similar chemical indicators between both extracts, including the presence of Artepellin C, suggest that the Baccharis dracunculifolia extract could be an alternative to the Green Propolis extract in the treatment of staph infections.

Interspecies transfer of plasmid-borne gentamicin resistance between Staphylococcus isolated from domestic dogs to Staphylococcus aureus.

As preconized by the One Health concept, the intimate relationship between pets and owners is a common source for the trade of microorganisms with zoonotic potential, and with them, antimicrobial resistance genes. In this work, we evaluated the presence of antimicrobial resistance genes, that are usually within mobile genetic elements, in a laboratory collection of 79 canine Staphylococcus strains, mostly Staphylococcus pseudintermedius and Staphylococcus coagulans. Resistance to tetracycline was observed in 34% of the strains, followed by resistance to erythromycin (21%) and gentamicin (19%). These phenotypes were partially correlated with the presence of the tetracycline resistance genes tet(M) and tet(K) in 64% and 44% of all strains, respectively; erythromycin resistance genes erm(A) and erm(C) in 53% and 23%; and gentamicin resistance gene aac(6')-aph(2″) in 26% of the strains. At least 45% of the strains harbored high- and/or low-molecular weight plasmids, whose transfer may be facilitated by their widespread biofilm-forming capacity, and absence of restrictive CRISPR systems. We selected eight plasmid-bearing and multidrug resistant strains, which were submitted to plasmid curing by stress with SDS. No strain lost resistance during stressing cultivation but, by conjugation experiments, the S. pseudintermedius strain 27 transferred its plasmid-borne resistance to gentamicin, conferred by the aac(6')-aph(2″) gene, to Staphylococcus aureus. The frequent empirical use of gentamicin to treat skin and ear infections in domestic dogs is likely to select resistant strains. Also, as demonstrated by our study, these strains can serve as gene reservoirs for human pathogens, such as S. aureus.

Comparative genomics of MRSA strains from human and canine origins reveals similar virulence gene repertoire.

Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen associated with a wide variety of infections in humans. The ability of MRSA to infect companion animals has gained increasing attention in the scientific literature. In this study, 334 dogs were screened for MRSA in two cities located in Rio de Janeiro State. The prevalence of MRSA in dogs was 2.7%. Genotyping revealed isolates from sequence types (ST) 1, 5, 30, and 239 either colonizing or infecting dogs. The genome of the canine ST5 MRSA (strain SA112) was compared with ST5 MRSA from humans-the main lineage found in Rio de Janeiro hospitals-to gain insights in the origin of this dog isolate. Phylogenetic analysis situated the canine genome and human strain CR14-035 in the same clade. Comparative genomics revealed similar virulence profiles for SA112 and CR14-035. Both genomes carry S. aureus genomic islands νSAα, νSAß, and νSAγ. The virulence potential of the canine and human strains was similar in a Caenorhabditis elegans model. Together, these results suggest a potential of canine MRSA to infect humans and vice versa. The circulation in community settings of a MRSA lineage commonly found in hospitals is an additional challenge for public health surveillance authorities.

Virulence Factors Found in Nasal Colonization and Infection of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates and Their Ability to Form a Biofilm.

Hospitalizations related to Methicillin-resistant Staphylococcus aureus (MRSA) are frequent, increasing mortality and health costs. In this way, this study aimed to compare the genotypic and phenotypic characteristics of MRSA isolates that colonize and infect patients seen at two hospitals in the city of Niterói-Rio de Janeiro, Brazil. A total of 147 samples collected between March 2013 and December 2015 were phenotyped and genotyped to identify the protein A (SPA) gene, the mec staphylococcal chromosomal cassette (SCCmec), mecA, Panton-Valentine Leucocidin (PVL), icaC, icaR, ACME, and hla virulence genes. The strength of biofilm formation has also been exploited. The prevalence of SCCmec type IV (77.1%) was observed in the colonization group; however, in the invasive infection group, SCCmec type II was prevalent (62.9%). The Multilocus Sequence Typing (MLST), ST5/ST30, and ST5/ST239 analyses were the most frequent clones in colonization, and invasive infection isolates, respectively. Among the isolates selected to assess the ability to form a biofilm, 51.06% were classified as strong biofilm builders. Surprisingly, we observed that isolates other than the Brazilian Epidemic Clone (BEC) have appeared in Brazilian hospitals. The virulence profile has changed among these isolates since the ACME type I and II genes were also identified in this collection.

First report of meticillin-resistant Staphylococcus aureus harboring mecC gene in milk samples from cows with mastitis in southeastern Brazil.

MRSA infection and colonization have been reported in both companion and food-chain animals, highlighting MRSA as an important veterinary and zoonotic pathogen. Another mec allele, the mecC gene, also confers beta-lactam resistance in Staphylococcus aureus and shows 69% nucleotide identity to mecA. The main aim of this study was to investigate the genotypic and clonal profile of methicillin-resistant S. aureus (MRSA) from cows with mastitis in dairy herds. Thirty-five samples suggestive of bovine subclinical mastitis were evaluated, and S. aureus were detected in all of them using both phenotypic and molecular approaches. According to the multilocus sequence typing (MLST), the S. aureus isolates were assigned in five different STs, 21 (60%) showed ST 742, 6 (17%) ST97, 4 (11%) ST1, 2 (6%) ST30, and 2 (6%) ST126. The presence of mecA was not observed in any of these isolates whereas mecC was detected in nine of them (9/35; 26%). The Panton-Valentine leukocidin (PVL) genes were detected in a total of 4 isolates. Among the 35 isolates analyzed, 26 showed resistance to penicillin. Changes in the S. aureus epidemiology due to the detection of MRSA in milk samples from cows presenting with bovine subclinical mastitis may have consequences for public health in Brazil, challenging the empirical therapy and animal management, with potential medical and social outcomes. To the best of our knowledge, this is the first report describing mecC MRSA in Southeastern Brazil.

Antimicrobial Resistance in Farm Animals in Brazil: An Update Overview.

In animal husbandry, antimicrobial agents have been administered as supplements to increase production over the last 60 years. Large-scale animal production has increased the importance of antibiotic management because it may favor the evolution of antimicrobial resistance and select resistant strains. Brazil is a significant producer and exporter of animal-derived food. Although Brazil is still preparing a national surveillance plan, several changes in legislation and timely programs have been implemented. Thus, Brazilian data on antimicrobial resistance in bacteria associated with animals come from official programs and the scientific community. This review aims to update and discuss the available Brazilian data on this topic, emphasizing legal aspects, incidence, and genetics of the resistance reported by studies published since 2009, focusing on farm animals and derived foods with the most global public health impact. Studies are related to poultry, cattle, and pigs, and mainly concentrate on non-typhoid Salmonella, Escherichia coli, and Staphylococcus aureus. We also describe legal aspects of antimicrobial use in this context; and the current occurrence of genetic elements associated with resistance to beta-lactams, colistin, and fluoroquinolones, among other antimicrobial agents. Data here presented may be useful to provide a better understanding of the Brazilian status on antimicrobial resistance related to farm animals and animal-derived food products.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry-based method for accurate discrimination of Staphylococcus schleiferi subspecies.

S. schleiferi is one of the main species isolated from canine otitis externa, pyoderma and from apparently healthy dogs. The species is divided into two subspecies, S. schleiferi schleiferi and S. schleiferi coagulans. MALDI-TOF MS does not distinguish correctly these two subspecies. This study aimed to identify biomarkers that could possibly discriminate Staphylococcus schleiferi subspecies by MALDI-TOF MS. Twelve strains (eight S. schleiferi schleiferi and four S. schleiferi coagulans) were firstly identified. Each isolate was submitted to a protein extraction protocol and subjected to spectrometry on Bruker Microflex LT mass spectrometer. Spectra were analyzed with the BioNumerics software v7.6. Our results showed that spectra clustered according to subspecies, and a set of five MALDI-TOF MS biomarkers were selected to enable the discrimination of S. schleiferi subspecies. In addition, these biomarkers were predicted to represent highly conserved proteins, which could contribute to the identification of subspecies-specific proteins that could be used for improved subspecies identification in clinical samples.

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.