Methicillin-resistant staphylococci in clinical bovine mastitis: occurrence, molecular analysis, and biofilm production.

Staphylococcus aureus is an important pathogen that causes mastitis in cattle, and the emergence of methicillin-resistant S. aureus (MRSA) poses a threat to veterinary and human medicine. The aims of the study were to investigate the prevalence of MRSA and methicillin-resistant coagulase-negative staphylococci (MR-CoNS) isolated from clinical mastitis, their ability to form biofilms, and the antimicrobial susceptibility of S. aureus strains. In addition, the Staphylococcal Cassette Chromosome mec (SCCmec) type, spa type and the presence of Panton-Valentine Leucocidin in MRSA were evaluated. A total of 326 staphylococcal strains were screened by multiplex-PCR for S. aureus and Staphylococcus intermedius group (SIG) identification. The S. aureus strains (n = 163) were subjected to phenotypic testing for antimicrobial susceptibility and biofilm formation. Molecular analysis was performed on MRSA mecA-positive strains. Of 163 S. aureus isolates, 142 strains (87.1%) were resistant to at least one antibiotic, and all 19 MRSA strains were resistant to at least four out of five antibiotics tested. All S. aureus strains harboured the icaA gene and were biofilm producers. Nineteen MR-CoNS strains were also isolated. The most prevalent spa types among MRSA were t001 (57.9%) and t037 (31.6%), while one MRSA was type t008 and one was type t041. Most MRSA were SCCmec type I (63.2%) and III (31.6%) and only one strain was type IV. None of the MRSA isolates had the PVL gene. The prevalence of multidrug-resistant S. aureus in bovine mastitis is a serious concern. The finding of MRSA with spa types predominant in humans and infrequent in Italian cows and with SCCmec infrequently found in bovine milk or cheese suggest a human origin of these strains. The ability of MRSA and MR-CoNS involved in bovine mastitis to be transferred to humans and vice versa poses a public health concern.

Detection and Identification of Mycoplasmopsis agassizii in Captive Tortoises with Different Clinical Signs in Italy.

Mycoplasmopsis agassizii causes the Upper Respiratory Tract Disease (URTD) in tortoises. The severity of the disease usually ranges from mild to severe respiratory signs. Animals can recover, die, or become asymptomatic carriers and are source of infection for other tortoises. This study describes (i) the clinical history and the results obtained in ten years of diagnostic PCR activity for detecting M. agassizii in different species of captive tortoises in Italy, and (ii) the phylogenetic analysis of the 16S rRNA gene sequences of M. agassizii. A total of 26.0% out of 169 samples resulted positive by PCR and 32 out of 75 (42.7%) animals with symptoms were positive. Sequences ob-tained from the PCR products were conserved, differed from the sequence of the M. agassizii type strain PS6, and were identical to many M. agassizii sequences deposited in databases. In particular, the sequences were identical or very similar to sequences obtained previously from tortoises in It-aly. Since samples collected from different anatomical sites resulted positive, it is suggested that pools of conjunctival, nasal and oral swabs are tested for diagnostic purpose in both symptomatic and asymptomatic animals.

Effect of a Probiotic Mixture in Captive Cheetahs (Acinonyx Jubatus) with Gastrointestinal Symptoms-A Pilot Study.

Cheetahs (Acinonyx jubatus) are classified as "vulnerable" species due to the low numbers persisting in the wild. Gastrointestinal diseases are very common in this species when they are kept in captivity, in particular gastritis. Clinical signs are predominantly characterized by vomiting, diarrhea, weight loss and anorexia. In this study, we evaluated the efficacy of a multi-strain probiotic in two groups of cheetahs: Group A (n = 4)-rescued cheetahs housed at the Cheetah Conservation Fund (Otjiwarongo, Namibia); Group B (n = 9)-captive cheetahs housed in Italian zoos. Animals showed gastrointestinal signs of different severity, and were positive for Helicobacter spp., detected by PCR in stool samples. Two sachets of probiotic formulation were administered to all cheetahs once a day for 21 consecutive days. Clinical conditions (appetite loss, vomiting, stool consistency and Body Condition Score) before (T0) and after 21 days of probiotic administration (T1) were then compared using a simplified Feline Chronic Enteropathy Activity Index (FCEAI) score. A slight but not significant improvement in the scores was observed in Group A, which had mild intestinal symptoms, while a significant decrease in vomiting and stool consistency (**p < 0.01) scores was observed in Group B, which had more pronounced symptoms. Results suggest that high concentrations of live probiotics can be of help in managing gastrointestinal signs in cheetahs.

Globetrotting strangles: the unbridled national and international transmission of Streptococcus equi between horses.

The equine disease strangles, which is characterized by the formation of abscesses in the lymph nodes of the head and neck, is one of the most frequently diagnosed infectious diseases of horses around the world. The causal agent, Streptococcus equi subspecies equi, establishes a persistent infection in approximately 10 % of animals that recover from the acute disease. Such 'carrier' animals appear healthy and are rarely identified during routine veterinary examinations pre-purchase or transit, but can transmit S. equi to naïve animals initiating new episodes of disease. Here, we report the analysis and visualization of phylogenomic and epidemiological data for 670 isolates of S. equi recovered from 19 different countries using a new core-genome multilocus sequence typing (cgMLST) web bioresource. Genetic relationships among all 670 S. equi isolates were determined at high resolution, revealing national and international transmission events that drive this endemic disease in horse populations throughout the world. Our data argue for the recognition of the international importance of strangles by the Office International des Épizooties to highlight the health, welfare and economic cost of this disease. The Pathogenwatch cgMLST web bioresource described herein is available for tailored genomic analysis of populations of S. equi and its close relative S. equi subspecies zooepidemicus that are recovered from horses and other animals, including humans, throughout the world. This article contains data hosted by Microreact.

Antibacterial Effect of Stainless Steel Surfaces Treated with a Nanotechnological Coating Approved for Food Contact.

Stainless steel, widely present in the food industry, is frequently exposed to bacterial colonization with possible consequences on consumers' health. 288 stainless steel disks with different roughness (0.25, 0.5 and 1 µm) were challenged with four Gram-negative (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 1402, Yersinia enterocolitica ATCC 9610 and Pseudomonas aeruginosa ATCC 27588) and four Gram-positive bacteria (Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 14579 and Listeria monocytogenes NCTT 10888) and underwent three different sanitizing treatments (UVC, alcohol 70% v/v and Gold lotion). Moreover, the same procedure was carried out onto the same surfaces after a nanotechnological surface coating (nanoXHAM® D). A significant bactericidal effect was exerted by all of the sanitizing treatments against all bacterial strains regardless of roughness and surface coating. The nanoXHAM® D coating itself induced an overall bactericidal effect as well as in synergy with all sanitizing treatments regardless of roughness. Stainless steel surface roughness is poorly correlated with bacterial adhesion and only sanitizing treatments can exert significant bactericidal effects. Most of sanitizing treatments are toxic and corrosive causing the onset of crevices that are able to facilitate bacterial nesting and growth. This nanotechnological coating can reduce surface adhesion with consequent reduction of bacterial adhesion, nesting, and growth.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Exhibits High Predicted Binding Affinity to ACE2 from Lagomorphs (Rabbits and Pikas).

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the pandemic COVID-19. The virus infects human cells by binding of the virus spike to the cell receptor ACE2. The crystal structure of SARS-CoV-2 spikes in complex with human ACE2 has recently been solved, and the main amino acid residues involved in the virus-receptor complex have been detected. To investigate the affinity of ACE2 of lagomorphs to the SARS-CoV-2 spike, ACE2 sequences from rabbits and American pikas were compared with human ACE2 and with ACE2 from mammals with different susceptibility to the virus. Models of the complex formed by SARS-CoV-2 spike and ACE2 from lagomorphs and from other mammals were created for comparative studies. ACE2 of lagomorphs showed fewer substitutions than human ACE2 in residues involved in the ACE2-SARS-CoV-2 spike complex, similar to cats. Analysis of the binding interface of the simulated complexes ACE2-SARS-CoV-2 spike showed high affinity of the ACE2 of lagomorphs to the viral spike protein. These findings suggest that the spike of SARS-CoV-2 could bind the ACE2 receptor of lagomorphs, and future studies should investigate the role of lagomorphs in SARS-CoV-2 epidemiology. Furthermore, the risks to humans coming into close contacts with these animals should be evaluated.

Evaluation of Three Different Vaccination Protocols against EHV1/EHV4 Infection in Mares: Double Blind, Randomized Clinical Trial.

EHV1 and EHV4 are the most important herpesviruses in horses. Repeated cases of abortion in mares regularly vaccinated, prompted us to investigate the immune response after vaccination with the same inactivated vaccine, but with three different protocols. Eighteen mares were chosen and randomly divided in three study groups (G1-G2-G3) and a control group (Ctrl). For serologic and PCR investigations nasal swabs, sera and blood were collected. The protocol used in G3 (4 doses) increased the titer recorded by ELISA and seroneutralization (SN). Poor agreement and no correlation were observed in titer values between ELISA and SN and between SN and PCR. A very weak positive correlation between ELISA and PCR was obtained. Seven out of 18 nasal swabs were positive by PCR; none showed viremia and no abortion occurred, regardless of vaccination status and despite active circulation of EHV-1 in the farm at the time of the study. The study was conducted in field conditions, in a susceptible population with a known history of infection and abortion, and among the three protocols, the one proposed in the G1 was the least efficient while the one proposed for the G3, seems to have induced a higher antibody titer in both SN and ELISA.

Equid alphaherpesvirus 1 from Italian Horses: Evaluation of the Variability of the ORF30, ORF33, ORF34 and ORF68 Genes.

Equid alphaherpesvirus 1 (EHV-1) is an important pathogen of horses. It is spread worldwide and causes significant economic losses. The ORF33 gene has a conserved region that is often used as target in diagnostic PCR protocols. Single nucleotide point (SNP) mutations in ORF30 are usually used to distinguish between neuropathogenic and non-neuropathogenic genotypes. An ORF68 SNP-based scheme has been used for grouping different isolates. Recently, the highest number of variable sites in EHV-1 from the UK has been found in ORF34. In this study, EHV-1 positive samples from Italian horses with a history of abortion were investigated by amplifying and sequencing the ORF30, ORF33, ORF34 and ORF68 genes. Most animals were infected by the neuropathogenic type A2254G. A 118 bp deletion was found at nucleotide positions 701-818 of the ORF68 gene, making impossible to assign the samples to a known group. Sequencing of the ORF34 gene with a newly designed nested PCR showed new SNPs. Analysis of these sequences and of those obtained from genetic databases allowed the identification of at least 12 groups. These data add depth to the knowledge of EHV-1 genotypes circulating in Italy.

Cytological Findings in Bronchoalveolar Lavage Fluid of Foals With Pneumonia Caused by Rhodococcus equi and Other Bacteria.

The distinction between lower respiratory tract infections caused by Rhodococcus equi and those caused by other pathogens is difficult. The aim of this retrospective study was to describe cytological findings in bronchoalveolar lavage fluid (BALF) of foals with pneumonia caused by R. equi or other bacteria. Nineteen foals aged from 3 weeks to 6 months with evidence of respiratory disease between 2015 and 2016 were selected from the database of the Veterinary Teaching Hospital "Mario Modenato" of the University of Pisa. Eight foals of 19 (42.1%) had R. equi pneumonia, whereas 11 of 19 (57.9%) had another bacterial pneumonia. R. equi-positive foals had statistically significant higher total nucleated cell count (P = .02) and neutrophils percentage (P = .002) than R. equi-negative ones. Macrophages proportion (P = .01) was lower in R. equi-positive than in R. equi-negative foals. Bronchoalveolar lavage is a quite easy procedure that can be performed in the field with minimal equipment required. Here we reported significant differences in the cellular composition of BALF that can be used to differentiate foals with R. equi bronchopneumonia from those with other bacterial pneumonias, whereas waiting for culture results.

Genotyping of Pestivirus A (Bovine Viral Diarrhea Virus 1) detected in faeces and in other specimens of domestic and wild ruminants at the wildlife-livestock interface.

Pestiviruses are widespread in the world among ungulates and infect both domestic and wild animals causing severe economic losses in livestock. Bovine Viral Diarrhea Virus type 1 (BVDV-1), now re-designated as Pestivirus A, causes diseases mainly in cattle, while few data are available about infection in wild ruminants and about the role of these animals in viral maintenance and spread. In order to investigate BVDV-1 infection in domestic and wild ruminants, especially at the wildlife/livestock interface, bulk tank milk from dairy cattle and sheep and spleen from red deer, roe deer and fallow deer were analysed. Furthermore, faecal samples from Apennine chamois and from wild deer were evaluated as a suitable sample for detecting and genotyping pestiviruses. BVDV-1 RNA was found in all animal species tested but not sheep. Genotyping based on partial 5'UTR and Npro sequences detected BVDV-1a in samples from Apennine chamois, red deer, roe deer and pasture-raised cattle, while BVDV-1c was found in a faecal sample from Apennine chamois and in a spleen sample from roe deer. For the first time BVDV-1 RNA was found and genotyped from faecal samples of wild ruminants and of cattle. BVDV-1a detection in Apennine chamois, red deer, roe deer and pasture-raised cattle suggests that the eventuality of viral transmission at the wildlife/livestock interface should be carefully evaluated. BVDV subgenotype 1c was found for the first time in roe deer and Apennine chamois in Central Italy, therefore the epidemiological role of these animals and the viral ecology should be further investigated.

Genetic diversity of Streptococcus equi subsp. zooepidemicus isolated from horses.

Streptococcus equi subsp. zooepidemicus (SEZ) is an opportunistic and zoonotic pathogen of horses. In this study, genetic intraspecies variability of SEZ obtained mainly from respiratory and genital samples of horses was investigated by analysis of the 16S-23S rRNA intergenic spacer region (ISR) and of the 16S rRNA gene. 16S-23S ISR rRNA type A1 was predominant, although a high rate of multiple products (30.5%) was obtained. Phylogenetic analysis of the 16S rRNA gene detected three genogroups (I, II and III). 16S rRNA variable regions V1 and V2 are the most important regions for evaluating SEZ intraspecies variability, but at least V1-V5 regions should be considered to avoid mistakes. Analysis of all 16S rRNA sequences available in databases assigned human SEZ to groups I and III but not to group II. These results show a high genetic variability in SEZ collected from different specimens of horses from various regions of Italy.

Denaturing Gradient Gel Electrophoresis Analysis of Bacteria in Italian Ticks and First Detection of Streptococcus equi in Rhipicephalus bursa from the Lazio Region.

Tick-borne diseases are an increasing problem for the community. Ticks harbor a complex microbial population acquired while feeding on a variety of animals. Profiling the bacterial population by 16S rDNA amplification and denaturing gradient gel electrophoresis enables detection of the broad spectrum of bacteria that settles in the ticks. This study identified known and unknown tick-infecting bacteria in samples from Italy. Seven adult ticks from different hosts and origins were analyzed: two Rhipicephalus sanguineus ticks from dogs (Lombardia), two Rhipicephalus bursa ticks from bovines (Lazio), and three Ixodes ricinus ticks from humans (Marche). The major result was the first report of the zoonotic agent Streptococcus equi in ticks. S. equi is a species complex of highly contagious pathogens. Subsequent to S. equi detection in a R. bursa tick removed from a bovine of Lazio in 2012, we studied 95 R. bursa samples collected from 3 bovines, 3 ponies, and 1 sheep grazing in the same area in 2012 and from 6 ponies grazing there in 2017. The results of a specific PCR assay indicated a not sporadic occurrence of S. equi in ticks. This finding provides a basis for assessing the potential of ticks to harbor and disperse S. equi.

Detection of Japanese Encephalitis Virus in bone marrow of healthy young wild birds collected in 1997-2000 in Central Italy.

Japanese Encephalitis Virus (JEV) is a flavivirus responsible for an important zoonotic, vector-borne disease included in the OIE list. JEV is endemic in a large area of Asia. In Italy, JEV has been found in dead birds collected in 1997-2000 and in a pool of Culex pipiens mosquitoes collected in 2010. Viral ecology in the inter-epidemic periods is not known. The aim of this study was to investigate JEV in FFPE archival samples of healthy birds collected in 1997-2000 in Tuscany (Italy) in the same area and a few months after collection of birds resulted infected by JEV. Different samples from 37 young birds and 83 adults were available. Immunohistochemistry detected JEV antigen only in bone marrow samples from 12 young healthy birds. Positive cells were morphologically referable to monocyte-macrophages lineage and were positive for anti-CD11b in serial sections. Real-time PCR detected JEV RNA in four of these samples. These results suggest that healthy birds can harbour JEV in bone marrow cells, while no other organs resulted infected. The role of healthy birds in JEV ecology should be better investigated. Surveillance programmes should include sampling of the most appropriate target organs.

Genetic Characterization and Phylogenetic Analysis of Small Ruminant Lentiviruses Detected in Spanish Assaf Sheep with Different Mammary Lesions.

Small Ruminant Lentiviruses (SRLVs) are widespread in many countries and cause economically relevant, slow, and persistent diseases in sheep and goats. Monitoring the genetic diversity of SRLVs is useful to improve the diagnostic tools used in the eradication programs. In this study, SRLVs detected in Spanish Assaf sheep with different grades of lymphoproliferative mastitis were sequenced. Genetic characterization showed that most samples belonged to type A and were closer to Spanish SRLV isolates previously classified as A2/A3. Four samples belonged to subtype B2 and showed higher homology with Italian B2 strains than with Spanish B2 isolates. Amino acid sequences of immuno-dominant epitopes in the gag region were very conserved while more alterations were found in the LTR sequences. No significant correlations were found between grades of mastitis and alterations in the sequences although samples with similar histological features were phylogenetically closer to each other. Broader genetic characterization surveys in samples with different grades of SRLV-lesions are required for evaluating potential correlations between SRLV sequences and the severity of diseases.

Beta-hemolytic Streptococcus dysgalactiae strains isolated from horses are a genetically distinct population within the Streptococcus dysgalactiae taxon.

The pathogenic role of beta-hemolytic Streptococcus dysgalactiae in the equine host is increasingly recognized. A collection of 108 Lancefield group C (n = 96) or L (n = 12) horse isolates recovered in the United States and in three European countries presented multilocus sequence typing (MLST) alleles, sequence types and emm types (only 56% of the isolates could be emm typed) that were, with few exceptions, distinct from those previously found in human Streptococcus dysgalactiae subsp. equisimilis. Characterization of a subset of horse isolates by multilocus sequence analysis (MLSA) and 16S rRNA gene sequence showed that most equine isolates could also be differentiated from S. dysgalactiae strains from other animal species, supporting the existence of a horse specific genomovar. Draft genome information confirms the distinctiveness of the horse genomovar and indicates the presence of potentially horse-specific virulence factors. While this genomovar represents most of the isolates recovered from horses, a smaller MLST and MLSA defined sub-population seems to be able to cause infections in horses, other animals and humans, indicating that transmission between hosts of strains belonging to this group may occur.

ATP-gated ionotropic P2X7 receptor controls follicular T helper cell numbers in Peyer's patches to promote host-microbiota mutualism.

Microbial colonization of the gut induces the development of gut-associated lymphoid tissue (GALT). The molecular mechanisms that regulate GALT function and result in gut-commensal homeostasis are poorly defined. T follicular helper (Tfh) cells in Peyer's patches (PPs) promote high-affinity IgA responses. Here we found that the ATP-gated ionotropic P2X7 receptor controls Tfh cell numbers in PPs. Lack of P2X7 in Tfh cells enhanced germinal center reactions and high-affinity IgA secretion and binding to commensals. The ensuing depletion of mucosal bacteria resulted in reduced systemic translocation of microbial components, lowering B1 cell stimulation and serum IgM concentrations. Mice lacking P2X7 had increased susceptibility to polymicrobial sepsis, which was rescued by Tfh cell depletion or administration of purified IgM. Thus, regulation of Tfh cells by P2X7 activity is important for mucosal colonization, which in turn results in IgM serum concentrations necessary to protect the host from bacteremia.

Conjunctival bacterial and fungal flora in clinically normal sheep.

OBJECTIVES: The aim was to identify conjunctival bacterial and fungal flora in clinically normal sheep. DESIGN: Prospective study. SETTING: Tuscany. PARTICIPANTS: 100 eyes from 50 adult Massese female sheep were examined. The sheep included in the study were considered free of anterior ophthalmic abnormalities. PRIMARY AND SECONDARY OUTCOME MEASURES: Bacteria were identified by morphological assessment, Gram staining, biochemical tests. Identification of filamentous fungi was achieved at the genus level, and Aspergillus species were identified based on keys provided by other authors. Yeast colonies were highlighted, but not identified. RESULTS: Positive cultures were obtained from 100/100 eyes for bacteria, and from 86/100 eyes for fungi. A total of 14 types of bacteria and 5 types of fungi were isolated. Yeasts were isolated from 13/100 eyes. The most frequent fungal isolates were saprophytic fungi. CONCLUSIONS: Conjunctival bacterial and fungal flora of clinically normal eyes were reported in sheep. The positivity obtained for conjunctival bacteria was higher compared to findings in the literature by other authors in the same species (100 per cent v 40 per cent), while our results were in line with a recent work performed on mouflons (Ovis Musimon) with a 100 per cent positivity for bacterial conjunctival fornix. In our survey, Gram-positive species were prevalent, as reported by other authors in different species. Few data are available in the literature regarding conjunctival fungal flora in healthy small ruminants. The prevalence of conjunctival fungal flora in this study was higher than findings reported in mouflons (86 per cent v 45 per cent). Differences in fungal prevalence may be due to different methods of managing herds, though further studies are required to verify this hypothesis. The similarities in bacterial and fungal isolates between sheep and mouflons suggest a genera pattern of conjunctival colonisation by bacteria and fungi.

Small ruminant lentivirus genotype B and E interaction: evidences on the role of Roccaverano strain on reducing proviral load of the challenging CAEV strain.

Live attenuated vaccines provide the most consistent protective immunity in experimental models of lentivirus infections. In this study we tested the hypothesis that animals infected with a naturally attenuated small ruminant lentivirus field strain of genotype E may control a challenge infection with a virulent strain of the caprine arthritis encephalitis virus (CAEV-CO). Within genotype E, Roccaverano strain has been described as attenuated since decreased arthritic pathological indexes were recorded in Roccaverano-infected animals compared to animals of the same breed infected with genotype B strains. Moreover, under natural conditions, animals double-infected with genotypes B and E appear less prone to develop SRLV-related disease, leading to a putative protective role of Roccaverano strain. Here we present evidence that goats experimentally infected with the avirulent genotype E SRLV-Roccaverano strain control the proviral load of a pathogenic challenge virus (CAEV-CO strain) more efficiently than naïve animals and appear to limit the spread of histological lesions to the contralateral joints.

Post-operative ocular infection due to Streptococcus dysgalactiae subspecies equisimilis.

Ocular infections due to Streptococcus dysgalactiae subsp. equisimilis are rare. In the present report, three patients with a history of uncomplicated small incision cataract surgery with intraocular lens implantation developed exogenous endophthalmitis due to Streptococcus dysgalactiae subsp. equisimilis. The identification of the organisms was confirmed by PCR for a 16S rRNA sequence specific to the species S. dysgalactiae. Intravitreal treatment of cefazolin and amikacin, in addition to topical ofloxacin and tobramycin, resulted in resolution of infection in all three patients. Our reports indicate the importance of bacterial culture and molecular identification in the diagnosis of S. dysgalactiae subsp. equisimilis infection in the eye.

Detection of Streptococcus dysgalactiae subsp. equisimilis in equine nasopharyngeal swabs by PCR.

Streptococcus (S.) dysgalactiae subsp. equisimilis is responsible for severe diseases in humans, including primary bacteraemia, pneumonia, endocarditis, and toxic shock syndrome. Infection in some animal species can also occur, although a few studies have looked into cross-species infectivity. In horses, S. equisimilis is generally considered infrequent or opportunistic, but has recently been isolated from cases of strangles-like disease. Rapid and sensitive diagnostic techniques could enable epidemiological studies and effective investigation of outbreaks involving these bacteria. In this study, PCR protocols previously described in cattle and in humans to detect the species S. dysgalactiae and the subspecies equisimilis were evaluated to detect specific sequences in equine samples. For this purpose, 99 monolateral nasal swabs were collected from horses from stud farms with a history of S. equisimilis infection and were tested blindly by bacteriological isolation and by single and duplex PCR. DNA for PCR was extracted both from the colonies grown on agar media and from enrichment broth aliquots after incubation with nasal swab samples. S. equisimilis was identified by bacteriological isolation in 23 out of 99 swab samples, and PCR assays on these colonies were fully concordant with bacteriological identification (kappa statistic = 1.00). In addition, PCR of the enrichment broth aliquots confirmed the bacteriological results and detected S. equisimilis in 6 samples more than the bacteriological examination (kappa statistic = 0.84). The PCR protocols appeared to be reliable for the rapid identification of S. equisimilis in equine nasal swab samples, and could be useful for microbiological diagnosis.