Antimicrobial resistance of Staphylococcus pseudintermedius isolates from healthy dogs and dogs affected with pyoderma in Japan

Staphylococcus pseudintermedius strains were isolated from healthy dogs and dogs with pyoderma in 2000-2002 and 2009. All the isolates from dogs with pyoderma in 1999-2000 and from healthy dogs in 2000-2002 and 2009 were susceptible to cefalexin and/or other cephalosporins and oxacillin. However, 7.1-12.5 and 11.4% of S. pseudintermedius isolates from dogs with pyoderma in 2009 were resistant to cephalosporins and oxacillin, respectively. All S. pseudintermedius isolates from dogs with pyoderma in 1999-2000 and those from healthy dogs in 2000-2002 were susceptible to fluoroquinolones; however, 50% of the S. pseudintermedius strains isolated from dogs with pyoderma in 2009 and 30% of the S. pseudintermedius strains isolated from healthy dogs in 2009 were resistant to fluoroquinolones. Of the 21 oxacillin-resistant S. pseudintermedius (MRSP) isolates, 11 carried SCCmec type V and 10 carried hybrid SCCmec types II-III. Staphylococcus pseudintermedius strains that were resistant to only one of three fluoroquinolones had a mutation in the quinolone resistance determination region of grlA, whereas S. pseudintermedius strains that were resistant to two or more fluoroquinolones had mutations in the quinolone resistance determination regions of both grlA and gyrA.     

Antimicrobial susceptibility of Staphylococcus aureus and Staphylococcus pseudintermedius isolated from various animals

This study characterized the antimicrobial susceptibility of 221 Staphylococcus aureus isolated from various species, and 60 canine Staphylococcus pseudintermedius isolated from 1986 through 2000 at the Western College of Veterinary Medicine (WCVM). Resistance of S. aureus was most common to penicillin (31%) and tetracycline (14%); resistance of S. pseudintermedius to penicillin was present in 8% and to tetracycline in 34% of isolates. Resistance to trimethoprim/sulfamethoxazole was only seen among S. pseudintermedius, and there was no resistance to amoxicillin/clavulanate, ampicillin/sulbactam, cephalothin, amikacin, gentamicin, enrofloxacin, chloramphenicol, or rifampin among any isolate. Inducible clindamycin resistance was found in both S. aureus and S. pseudintermedius, highlighting the need for careful interpretation of culture and susceptibility test results. There were significant differences in the minimum inhibitory concentrations of penicillin, ciprofloxacin, enrofloxacin, clindamycin, erythromycin, chloramphenicol, and tetracycline between avian, bovine, equine, and porcine isolates.     

广东省宠物源伪中间型葡萄球菌的耐药性调查研究

为调查广东省宠物源伪中间型葡萄球菌(Staphylococcus pseudintermedius)的携带和耐药情况,从小动物临床采集皮肤、耳部和鼻腔等部位的样品,分离鉴定伪中间型葡萄球菌,并采用琼脂稀释法和纸片扩散法对伪中间型葡萄球菌进行抗菌药物敏感性检测,采用PCR方法检测mecA基因。结果表明,从898个样品中共分离到144株伪中间型葡萄球菌,检出率为16.0%,皮肤、耳部和鼻腔的伪中间型葡萄球菌检出率分别为20%(64/319)、17.8%(64/359)和7.5%(3/40)。抗菌药物敏感性检测和mecA基因检测结果显示有89株(61.8%)为耐甲氧西林伪中间型葡萄球菌(MRSP)。伪中间型葡萄球菌对氨苄西林、红霉素、阿奇霉素、克林霉素和四环素的耐药率均在80%以上,对利福平和阿米卡星的耐药率低于8%,对万古霉素、利奈唑胺、喹奴普汀/达福普汀和替考拉宁均敏感。大部分(>69%)MRSP对红霉素、克林霉素、泰乐菌素、阿奇霉素、复方新诺明、四环素、环丙沙星和恩诺沙星等抗菌药物表现耐药。本研究结果表明宠物源伪中间型葡萄球菌的耐药情况严重且MRSP的检出率高,应高度重视宠物源细菌耐药问题。     

Carriage of methicillin-resistant Staphylococcus pseudintermedius in small animal veterinarians: indirect evidence of zoonotic transmission

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is increasingly reported in small animals and cases of human infections have already been described despite its recent emergence in veterinary practice. We investigated the prevalence of MRSP and methicillin-resistant Staphylococcus aureus (MRSA) among small animal dermatologists attending a national veterinary conference in Italy. Nasal swabs were obtained from 128 veterinarians, seven of which harboured MRSP (n = 5; 3.9%) or MRSA (n = 2; 1.6%). A follow-up study of two carriers revealed that MRSP persisted for at least 1 month in the nasal cavity. Methicillin-susceptible S. aureus (MSSA) was isolated from 32 (25%) conference participants, whereas methicillin-susceptible S. pseudintermedius (MSSP) was not detected, suggesting that MRSP may have a particular ability to colonize humans compared to MSSP. All isolates were characterized by spa typing. Methicillin-resistant isolates were further typed by antimicrobial susceptibility testing, SCCmec and multi-locus sequence typing. Two lineages previously associated with pets were identified among the five MRSP isolates; the European epidemic clone ST71-SCCmec II-III and ST106-SCCmec IV. One of the two MRSA isolates displayed a genotype (ST22- SCCmecIV) frequently reported in dogs and cats. MRSP isolates were resistant to more antimicrobial agents compared with MRSA isolates and displayed the typical multidrug resistance patterns of MRSP in pets. The 32 MSSA isolates belonged to 20 spa types and the most frequent types (t12, t15 and t166) were associated with common S. aureus lineages in humans (CC30 and CC45). Although low, the 3.9% MRSP carriage rate found among small animal dermatologists was surprising in consideration of the rare occurrence of S. pseudintermedius in humans, the lack of MSSP detection and the recent appearance of MRSP in Europe. As cases of human MRSP infection have been linked with pets, veterinarians should be aware of this zoonotic risk and proper preventative measures should be taken to avoid MRSP transmission from animal patients.     

In vitro antimicrobial resistance of staphylococci isolated from canine urinary tract infection

This study determined the diversity of species and antimicrobial resistance of staphylococci isolated from dogs with a presumptive diagnosis of urinary tract infection (UTI). Urine samples from 348 dogs with clinical signs of UTI, according to clinical examination and urinalysis, were processed for isolation of Staphylococcus. Colonies in pure culture were identified by biochemical reactions and tested for susceptibility to 15 antimicrobials. Seventy isolates of staphylococci were obtained (20.1%). Staphylococcus pseudintermedius was the most frequent species (32.8%), followed by S. epidermidis (18.6%), S. simulans (15.7%), S. schleiferi schleiferi (11.4%), S. aureus (11.4%), S. schleiferi coagulans (7.2%) and S. saprophyticus (2.9%). All the isolates were resistant to at least 1 drug and 77.1% were multiresistant. The study reports the alarming antimicrobial resistance of members of the Staphylococcus genus isolated from canine UTI and highlights the importance of coagulase-negative staphylococci in its etiology.     

Staphylococcal colonization of mucosal and lesional skin sites in atopic and healthy dogs

Staphylococcal colonization was compared in healthy dogs and in dogs with atopic dermatitis. Bacterial swabs were collected from the nasal mucosa, ear and perineum of 43 healthy and 24 atopic dogs and also from potentially infected skin lesions of the atopic dogs. Coagulase positive staphylococcal isolates were identified to the species level. At the time of this study Staphylococcus intermedius was considered a single species but has since been recognized as comprising at least three species with canine isolates believed to belong to Staphylococcus pseudintermedius . Of atopic dogs, 87.5% were colonized with S. intermedius compared to only 37.2% of healthy dogs. The ear was the only carriage site that showed any significant difference in S. intermedius isolation between healthy and atopic dogs. The perineum represented the most frequently colonized mucosal site for both groups. Sampling the nasal mucosa alone identified 71.4% of atopic and 37.5% of healthy S. intermedius carriers. Inclusion of a perineal swab identified 100% of atopic and 93.8% of healthy carriers. S. intermedius was isolated from all the lesional sites sampled from atopic dogs. Significantly fewer dogs were colonized by Staphylococcus aureus than S. intermedius , and there was no significant difference between S. aureus colonization of atopic and healthy dogs. S. aureus was not recovered from any lesions in atopic dogs. The results show that S. intermedius carriage is more prevalent in atopic dogs compared to healthy dogs and that to identify staphylococcal carriers both the nasal mucosa and the perineum should be sampled.     

Comparative assessment of genotypic and phenotypic correlates of Staphylococcus pseudintermedius strains isolated from dogs with otitis externa and healthy dogs

Staphylococcus pseudintermedius is considered a primary pathogen of canine skin and soft tissue infections, and the rapid emergence of methicillin-resistant S. pseudintermedius worldwide is a major issue. In the current study, genotypic and phenotypic correlates associated with S. pseudintermedius causing canine otitis externa were evaluated using 41 S. pseudintermedius strains isolated from dogs with otitis externa (n = 26) and healthy dogs (n = 15). The S. pseudintermedius strains were subjected to a comparative analysis of (i) genotypes (multilocus sequence typing, agr, and spa types), (ii) methicillin resistance and SCCmec types, (iii) multidrug resistance (MDR), (iv) biofilm formation, and (v) susceptibility to canine cathelicidin (K9CATH). A high degree of genetic diversity was observed in both groups of S. pseudintermedius strains, regardless of methicillin resistance. Almost all methicillin-resistant strains (>95%) harbored SCCmec V and displayed MDR. Although there was no difference in biofilm formation, S. pseudintermedius strains derived from otitis externa exhibited enhanced resistance to cationic antimicrobial peptide (K9CATH) compared with strains from healthy dogs. The high degree of heterogeneity in MLST, agr, and spa types prevented the identification of correlations between any specific genotype and virulence phenotype in otitis externa caused by S. pseudintermedius, These findings provide an important basis for monitoring and treating canine skin and soft tissue infections in Korea.     

Methicillin-resistant Staphylococcus pseudintermedius among dogs admitted to a small animal hospital

The aim of this study was to determine the frequency of carriage of methicillin-resistant Staphylococcus pseudintermedius (MRSP) among dogs admitted to a small animal hospital during a 17-month period, to characterize these isolates and to initially screen for possible factors associated with MRSP carriage. Swabs were taken from the nose/pharynx and the perineum as well as from wounds and skin infections (if present) of 814 dogs before entering the small animal hospital. A questionnaire for background information was completed. The staphylococcal species and methicillin resistance were confirmed pheno- and genotypically. The identified MRSP isolates were characterized by SCCmec typing, testing for susceptibility to 25 antimicrobial agents and SmaI-directed pulsed-field gel electrophoresis. A first screening for possible risk factors for MRSP carriage was performed by means of unifactorial contingency tables and CART analysis. Sixty (7.4%) dogs were positive for MRSP. All MRSP isolates harboured a type II-III SCCmec cassette and showed extended resistance to antimicrobial agents. Fifteen different SmaI patterns were observed. The major factors that clustered with MRSP carriage were former hospitalization and antibiotic treatment within the last six months before sampling. This study showed that only a minor part of the sampled dogs carried multi-resistant MRSP isolates. The facts that prior hospitalization and/or antibiotic therapy are potential associated factors for MRSP carriage underline the necessity of a judicious use of antibiotics in small animal medicine.     

Tandem repeat sequence analysis of staphylococcal protein A (spa) gene in methicillin-resistant Staphylococcus pseudintermedius

A putative staphylococcal protein A (spa) gene was discovered in the genome of Staphylococcus pseudintermedius and used for developing a species-specific spa typing protocol. Thirty-one clinical methicillin-resistant S. pseudintermedius (MRSP) isolates from dogs and cats in four countries were characterized by spa typing, pulsed-field gel electrophoresis (PFGE) and staphylococcal cassette chromosome (SCCmec) typing. The results indicated the occurrence of two MRSP clones that acquired distinct SCCmec elements in Europe (t02, PFGE type A, SCCmec type III,) and California (t06, PFGE type B, SCCmec type V). Sequence analysis of mecA revealed the occurrence of four alleles (mecA1 to mecA4), which correlated with the geographical origin of the isolates and enabled discrimination of two distinct subtypes within the European clone. The newly developed spa typing method appeared to be a promising tool for easy and rapid typing of MRSP, either alone or in combination with SCCmec and mecA typing for fine-structure epidemiological analysis.     

A real-time PCR assay to detect the Panton Valentine Leukocidin toxin in staphylococci: screening Staphylococcus schleiferi subspecies coagulans strains from companion animals

Recent reports suggest that methicillin-resistant strains of Staphylococcus schleiferi subspecies coagulans are now commonly isolated from dogs. Given the association of a potentially mobile SCCmec type IV element with lysogenic phage-encoded Panton Valentine Leukocidin (PVL) toxin genes in community-acquired methicillin-resistant Staphylococcus aureus strains we hypothesized that methicillin-resistant S. schleiferi ssp. coagulans strains may also encode PVL toxin genes. Forty S. schleiferi ssp. coagulans strains isolated from companion animals were studied. Susceptibility to oxacillin was determined by broth microdilution and all isolates were screened by PCR for the presence of the mecA gene. SCCmec typing was performed on 14 isolates. A real-time PCR assay was developed for the detection of the PVL genes using a SmartCycler. Pulsed-field gel electrophoresis (PFGE) was performed to determine whether S. schleiferi ssp. coagulans strains were homogeneous. Twenty-eight of the 40 isolates (70%) were resistant to oxacillin and 26/28 possessed the mecA gene by PCR. SCCmec IV was identified in seven strains; the other seven isolates were not typable by this technique. All 40 strains were negative for the PVL toxin gene. PFGE showed a heterogeneous population and 13 different profiles were determined. In conclusion, this study showed that PVL toxin genes were not detected in a heterogeneous population of methicillin-resistant S. schleiferi ssp. coagulans strains isolated from companion animals.     

Urinary tract infection caused by methicillin-resistant Staphylococcus pseudintermedius in a dog

A young neutered male pug dog was presented for evaluation of acute onset pollakiuria and hematuria. Culture and susceptibility testing of urine identified a methicillin-resistant Staphylococcus pseudintermedius, which was susceptible to only tetracycline among commonly used antimicrobials. Treatment with doxycycline led to bacteriological cure and resolution of clinical signs.     

Methicillin resistance among staphylococci isolated from dogs

OBJECTIVE: To determine whether methicillin-resistant staphylococci from dogs expressed the mecA gene and to determine what proportion of canine staphylococcal isolates positive for the mecA gene were resistant to oxacillin and other antibiotics. SAMPLE POPULATION: 25 methicillin-resistant (10 coagulase-positive and 15 coagulase-negative) and 15 methicillin-susceptible (8 coagulase-positive and 7 coagulase-negative) staphylococci isolated from dogs. PROCEDURE: All strains were tested for methicillin resistance by use of oxacillin agar screening and identified by use of standard techniques. Minimum inhibitory concentrations of 16 antibiotics were determined for all 40 isolates. A polymerase chain reaction method targeting a 533-basepair fragment of the mecA gene was used to detect mecA gene expression. RESULTS: 23 of the 25 methicillin-resistant isolates and none of the methicillin-susceptible isolates possessed the mecA gene. For 10 of 16 antibiotics, the proportion of mecA-positive isolates that were resistant or of intermediate susceptibility was significantly higher than the proportion of mecA-negative isolates that were resistant or of intermediate susceptibility. Only 1 methicillin-resistant coagulase-positive isolate was identified as Staphylococcus intermedius; the other 9 were identified as S. aureus. CONCLUSIONS AND CLINICAL RELEVANCE: Results confirm that staphylococci isolated from dogs may have methicillin resistance mediated by the mecA gene. Isolates positive for the mecA gene were more likely to be resistant to various antibiotics than were isolates negative for the mecA gene. Results suggest that in dogs, infections caused by staphylococci that have the mecA gene may be difficult to treat because of resistance to antibiotics.     

Antimicrobial activity of gallium maltolate against Staphylococcus aureus and methicillin-resistant S. aureus and Staphylococcus pseudintermedius: An in vitro study

Gallium is a trivalent semi-metallic element that has shown antimicrobial activity against several important human pathogens. This antimicrobial activity is likely related to its substitution in important iron-dependent pathways of bacteria. The genus Staphylococcus, which includes human and animal pathogens that cause significant morbidity and mortality, requires iron for growth and colonization. In this study, gallium maltolate, at various concentrations between 50 and 200μM, inhibited the in vitro growth of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at time-points between 8 and 36h after inoculation. The inhibitory activity of gallium maltolate against clinical isolates of MRSA and methicillin-resistant Staphylococcus pseudintermedius (MRSP) from a veterinary teaching hospital was determined.     

Insertion sequence IS256 in canine pyoderma isolates of Staphylococcus pseudintermedius associated with antibiotic resistance

Staphylococcus pseudintermedius is the most frequent staphylococcal species isolated from canine pyoderma. The control of S. pseudintermedius infection is often difficult due to the expanded antimicrobial resistance phenotypes. Antibiotic resistance in staphylococcal pathogens is often associated to mobile genetic elements such as the insertion sequence IS256 that was first described as a part of the transposon Tn4001, which confers aminoglycoside resistance in Staphylococcus aureus and in Staphylococcus epidermidis. In this study a collection of 70 S. pseudintermedius isolates from canine pyoderma was used to investigate antimicrobial susceptibility to 15 antibiotics and the presence of IS256, not revealed in S. pseudintermedius yet. Antibiotic resistance profiling demonstrated that all S. pseudintermedius isolates had a multi-drug resistance phenotype, exhibiting simultaneous resistance to at least five antibiotics; indeed methicillin resistant S. pseudintermedius isolates were simultaneously resistant to at least nine antibiotics and all were also gentamicin resistant. PCR analyses revealed the presence of IS256 in 43/70 S. pseudintemedius isolates. The association between the presence of IS256 and the resistance was particularly significant for certain antibiotics: cefovecin, amikacin, gentamicin and oxacillin (χ(2)p-value<0.05). However, there was a striking result in frequency of strains resistant to gentamicin and oxacillin, suggesting a specific association between the presence of the IS256 element and the determinants for the resistance to these antibiotics. To the best of our knowledge, this is the first report showing the detection of IS256 in S. pseudintermedius isolates and its association with antibiotic resistance. Our findings suggest that S. pseudintermedius may acquire antibiotic resistance genes through mobile genetic elements which may play a predominant role in the dissemination of multi-drug resistance.     

Screening for skin carriage of methicillin-resistant coagulase-positive staphylococci and Staphylococcus schleiferi in dogs with healthy and inflamed skin

Methicillin resistance rates of 41% for Staphylococcus aureus, 16% for S. intermedius, and 40% for S. schleiferi have recently been reported in canine patients. These were deemed to be reflective of referral and clinician-selection biases, which would imply significantly lower methicillin-resistant staphylococcal carriage rates in less-biased canine populations. In this study, swabs for bacterial culture were collected from five cutaneous sites on each of 50 healthy dogs and 59 dogs with inflammatory skin disease to determine prevalence of carriage and relative frequency of methicillin resistance in coagulase-positive staphylococci and S. schleiferi ssp. schleiferi. These were identified morphologically and by Gram's staining, catalase and coagulase testing, and biochemical speciation. Coagulase-positive staphylococci and S. schleiferi ssp. schleiferi were isolated from 88% (52 of 59) of affected dogs. Species identified in the culture-positive dogs were: S. aureus in 12%, S. intermedius (92%), S. schleiferi ssp. schleiferi (10%), and S. schleiferi ssp. coagulans (10%) with methicillin resistance rates of 17%, 8%, 20% and 20%, respectively. Coagulase-positive staphylococci were isolated from 74% (37 of 50) of healthy dogs: S. aureus (16%), S. intermedius (92%) and S. schleiferi ssp. coagulans (5%). Methicillin resistance rates were 0%, 3% and 50%, respectively. Of total methicillin-resistant isolates, 11 of 13 were positive for PBP2a via latex agglutination. Methicillin-resistant S. intermedius and S. schleiferi ssp. schleiferi isolates were all positive for the mecA gene via PCR. There was no significant difference in staphylococcal isolation or methicillin resistance between study groups. While present, methicillin-resistant coagulase-positive staphylococci are significantly less common in these less-biased populations than in the clinical isolates previously reported from this institution which provided the impetus for this study.     

Isolation of Staphylococcus schleiferi from dogs with pyoderma

OBJECTIVE: To determine frequency with which Staphylococcus schleiferi could be isolated from dogs with pyoderma and antimicrobial susceptibility patterns of isolates that were obtained. DESIGN: Prospective study. ANIMALS: 54 dogs with a first (n = 14) or recurrent (40) episode of pyoderma. PROCEDURE: Specimens were obtained and submitted for bacterial culture. Isolates were identified as S schleiferi on the basis of growth and biochemical characteristics. Two isolates were submitted for DNA sequencing to confirm identification. Methicillin susceptibility was determined by means of disk diffusion with oxacillin-impregnated disks. RESULTS: 3 of 14 dogs examined because of a first episode of pyoderma and 12 of 40 dogs examined because of a recurrent episode of pyoderma were receiving antimicrobials at the time of specimen collection. Staphylococcus schleiferi was not isolated from any dog with first-time pyoderma but was isolated from 5 dogs with recurrent pyoderma that were not receiving antimicrobials at the time of specimen collection and 10 dogs with recurrent pyoderma that were receiving antimicrobials. Nine isolates were identified as S schleiferi subsp schleiferi, and 6 were identified as S schleiferi subsp coagulans. All S schleiferi subsp schleiferi isolates were resistant to methicillin, but only 2 S schleiferi subsp coagulans isolates were. Two methicillin-resistant isolates were also resistant to fluoroquinolones, and 1 isolate had intermediate susceptibility to fluoroquinolones. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that S schleiferi subsp schleiferi and S schleiferi subsp coagulans may be isolated from dogs with recurrent pyoderma. Although isolates from dogs with pyoderma were frequently resistant to methicillin, multiple drug resistance was uncommon.     

Screening for methicillin-resistant staphylococci in dogs admitted to a veterinary teaching hospital

This study investigated the nasal carriage of methicillin-resistant staphylococci (MRS) in dogs (n=177) prior to medical examination or surgery in a veterinary teaching hospital. Nasal swab samples were collected after induction of anaesthesia and incubated overnight in salt enriched trypticase-soy broth. Cultures were analysed on two different agar media containing cefoxitin. Suspected MRS isolates were genotypically identified and characterised by antimicrobial susceptibility testing and staphylococcal cassette chromosome mec (SCCmec)-typing. Methicillin-resistant Staphylococcus aureus (MRSA) isolates were additionally characterised by spa-typing and multilocus sequence typing. The presence of Panton-Valentine leukocidin (pvl) genes was determined by PCR. MRS carriage was compared between animals with or without an infectious process. Two MRSA were isolated, both belonging to typical Belgian human hospital clones and lacking pvl. Additionally a methicillin-resistant Staphylococcus haemolyticus carrying a type V SCCmec was detected. No relationship was observed between MRS carriage and presence of infections. The results suggest that MRS are present in dogs originating from the community, albeit at a low prevalence. This could pose risks for cross contamination of dogs and their owners.     

A veterinary perspective on methicillin-resistant staphylococci

Objective – To familiarize the reader with the epidemiology, diagnosis, and infectious and zoonotic potential of methicillin-resistant staphylococci.
Data sources – Original research publications, scientific reviews and abstracts, case reports, and conference proceedings.
Human Data Synthesis – Staphylococcus aureus is a common human commensal organism; acquisition of genes encoding an altered penicillin-binding protein confers resistance to β-lactam antimicrobial drugs. Methicillin-resistant S. aureus (MRSA) are often resistant to non–β-lactam antimicrobial drugs as well. Originally described as an important cause of nosocomial infection, MRSA colonization and infection are now often identified in humans outside healthcare settings. Like other S. aureus , MRSA may be present without clinical illness. However, when they do cause infection the consequences can be extremely serious.
Veterinary Data Synthesis – The major domestic animal species, including pets and livestock, may become contaminated, colonized, or infected with methicillin-resistant staphylococci, including MRSA. Dogs and cats are more likely to be colonized/infected with Staphylococcus pseudintermedius than S. aureus , but this pathogen can acquire genes encoding methicillin resistance (ie, MRSP). Diagnosis of MRSA or MRSP has implications not only for treatment of infected animals, but for potential zoonotic transmission.
Conclusions – MRSA infection is an important cause of morbidity and mortality in humans. Animals may be contaminated, colonized, or infected with MRSA, with implications for the animal's health and as a potential reservoir for human infection. Staphylococci other than S. aureus may also acquire genes for methicillin resistance, and these species can also result in animal and occasionally human morbidity or mortality.     

Antibiotic resistance of staphylococci from humans, food and different animal species according to data of the Hungarian resistance monitoring system in 2001

Based on data of the Hungarian resistance monitoring system the antibiotic resistance of Staphylococcus strains of human and animal origin was studied. No methicillin-resistant staphylococci harbouring mecA gene were isolated from animals in 2001. Penicillin resistance, mediated by penicillinase production, was the most frequent among Staphylococcus aureus strains isolated from humans (96%), from bovine mastitis (55%), from foods (45%) and from dogs. In staphylococci isolated from animals low resistance percentages to aminoglycosides (0-2%), fluoroquinolones (0.5-3%) and sulphonamides (0.5-4%) were found but in strains isolated humans these figures were higher (1-14%, 5-18% and 3-31%, respectively). The most frequent antibiotic resistance profiles of strains isolated from animals and food were penicillin/tetracycline, penicillin/lincomycin and penicillin/lincomycin/tetracycline. Penicillin/tetracycline resistance was exhibited by strains from mastitis (3), samples from the meat industry (31), poultry flocks (1), poultry industry (1), noodle (1) and horses (2). Penicillin/lincomycin resistance was found in 10 Staphylococcus strains from mastitis, 1 from the dairy industry, 1 from the meat industry and 6 from dogs. Isolates from mastitis (2), from the dairy industry (2), from pigs (1), from the meat industry (1) and from poultry (1) harboured penicillin/lincomycin/tetracycline resistance pattern. Multiresistant strains were usually isolated only from one and sometimes from two animal species; therefore, the spread of defined resistant strains (clones) among different animal species could not be demonstrated. These results also suggest that the transfer of antibiotic resistance of S. aureus from animals to humans probably occurs less frequently than is generally assumed.