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1.
This study reports the susceptibility to antimicrobial agents of staphylococci (n=105) isolated from dogs, and the factors associated with this resistance. The study animals were 23 healthy dogs (group A), 24 with first-time pyoderma (group B), and 27 with recurrent pyoderma that had undergone long-term antibiotic treatment (group C). Staphylococci were more commonly isolated from the pyoderma-affected than the healthy dogs (p<0.0001). Some 78% of the isolates were resistant to at least one antimicrobial agent. Resistance to amoxicillin-clavulanate, cephalosporins (OR 4.29, 95% CI [1.15, 16.3] respectively), enrofloxacin (OR 9.47, 95% CI [1.53, 58.5]) and ciprofloxacin (OR 79.7 95% CI [3.26, 1947.4]) was more common among group C isolates. Some 32% of all the isolates were multiresistant (MR) and 10.4% were methicillin-resistant (MRS). The probability of isolating MRS staphylococci in group C increased by a factor of four (95% CI [1.18, 17.9]) compared to A plus B. Multi-resistant (MR) isolates were obtained more commonly from urban than rural dogs (OR 3.79, 95% CI [1.09, 13.17]). All the MRS staphylococci encountered were obtained from urban dogs and more commonly from male dogs (p=0.07). This study shows that dogs bred in urban habitat, with a history of antibiotic therapy in the past year represents significant risk of being carriers of isolates resistant to methicillin (MRS) and other antimicrobials. These factors should be considered before applying an antimicrobial treatment in veterinary clinics.  相似文献   

2.
OBJECTIVE: To assess the prevalence and patterns of antimicrobial resistance among Escherichia coli strains isolated from the urine of women with cystitis or pyelonephritis and from fecal samples from dogs and healthy humans. DESIGN: Cross-sectional survey. SAMPLE POPULATION: Escherichia coli isolates from 82 women with cystitis, 170 women with pyelonephritis, 45 dogs, and 76 healthy human volunteers. PROCEDURE: Susceptibility to 12 antimicrobial agents was determined by means of disk diffusion testing as specified by the NCCLS. RESULTS: Overall, the 4 most common antimicrobial resistance patterns were resistance to ampicillin, sulfisoxazole, trimethoprim, and trimethoprim-sulfamethoxazole (n = 45 [12% of all isolates]); ampicillin alone (33 [9%]); ampicillin and sulfisoxazole (29 [8%]); and sulfisoxazole alone (14 [4%]). None of the isolates were resistant to ceftazidime, ciprofloxacin, nitrofurantoin, or piperacillin-tazobactam. Resistance was significantly more common and extensive among isolates from women with cystitis or pyelonephritis than among isolates from healthy humans or dogs. Resistance was least common among isolates from dogs. The only resistance phenotype that was more common among canine isolates than human isolates was resistance to sulfisoxazole alone. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that dogs are unlikely to be an important external reservoir of antimicrobial-resistant E. coli strains causing infections in humans. On the contrary the data suggest that dogs conceivably could acquire resistant E. coli strains from humans.  相似文献   

3.
Data on the prevalence of antimicrobial resistant enterococci and staphylococci from the poultry production environment are sparse in the United States. This information is needed for science-based risk assessments of antimicrobial use in animal husbandry and potential public-health consequences. In this study, we assessed the susceptibility of staphylococci and enterococci isolated from poultry litter, recovered from 24 farms across Georgia, to several antimicrobials of veterinary and human health importance. Among the 90 Enterococcus isolates recovered, E. hirae (46%) was the most frequently encountered species, followed by E. faecium (27%), E. gallinarum (12%), and E. faecalis (10%). Antimicrobial resistance was most often observed to tetracycline (96%), followed by clindamycin (90%), quinupristin-dalfopristin (62%), penicillin (53%), erythromycin (50%), nitrofurantoin (49%), and clarithromycin (48%). Among the 110 staphylococci isolates recovered, only coagulase-negative staphylococci (CNS) were identified with the predominant Staphylococcus species being S. sciuri (38%), S. lentus (21%), S. xylosus (14%) and S. simulans (12%). Resistance was less-frequently observed among the Staphylococcus isolates for the majority of antimicrobials tested, as compared with Enterococcus isolates, and was primarily limited to clarithromycin (71%), erythromycin (71%), clindamycin (48%), and tetracycline (38%). Multidrug resistance (MDR) phenotypes were prevalent in both Enterococcus and Staphylococcus; however, Enterococcus exhibited a statistically significant difference in the median number of antimicrobials to which resistance was observed (median = 5.0) compared with Staphylococcus species (median = 3.0). Because resistance to several of these antimicrobials in gram-positive bacteria may be attributed to the shuttling of common drug-resistance genes, we also determined which common antimicrobial-resistance genes were present in both enterococci and staphylococci. The antimicrobial resistance genes vat(D) and erm(B) were present in enterococci, vgaB in staphylococci, and mobile genetic elements Tn916 and pheromone-inducible plasmids were only identified in enterococci. These data suggest that the disparity in antimicrobial-resistance phenotypes and genotypes between enterococci and staphylococci isolated from the same environment is, in part, because of barriers preventing exchange of mobile DNA elements.  相似文献   

4.
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.  相似文献   

5.
Antimicrobial susceptibility testing was performed on a total of 581 clinical Escherichia coli isolates from diarrhea and edema disease in pigs, from acute mastitis in dairy cattle, from urinary tract infections in dogs and cats, and from septicemia in laying hens collected in Switzerland between 1999 and 2001. Among the 16 antimicrobial agents tested, resistance was most frequent for sulfonamides, tetracycline, and streptomycin. Isolates from swine presented significantly more resistance than those from the other animal species. The distribution of the resistance determinants for sulfonamides, tetracycline, and streptomycin was assessed by hybridization and PCR in resistant isolates. Significant differences in the distribution of resistance determinants for tetracycline (tetA, tetB) and sulfonamides (sulII) were observed between the isolates from swine and those from the other species. Resistance to sulfonamides could not be explained by known resistance mechanisms in more than a quarter of the sulfonamide-resistant and sulfonamide-intermediate isolates from swine, dogs and cats. This finding suggests that one or several new resistance mechanisms for sulfonamides may be widespread among E. coli isolates from these animal species. The integrase gene (intI) from class I integrons was detected in a large proportion of resistant isolates in association with the sulI and aadA genes, thus demonstrating the importance of integrons in the epidemiology of resistance in clinical E. coli isolates from animals.  相似文献   

6.
We conducted an epidemiological study of Staphylococcus intermedius using arbitrarily primed PCR (AP-PCR) and antibiograms. One hundred and twenty-five S. intermedius isolates were recovered from the oral cavity and/or cranial hair coat of healthy dogs enrolled in a pet therapy program. Commensal S. intermedius was cultured from 32% of the oral cavity cultures and 13% of the cranial hair coat cultures. We characterized the colonization of the dogs as transient, intermittent, or persistent. For dogs characterized as persistently colonized, 73% of the isolates came from the oral cavity. These isolates were also genotyped by AP-PCR. A single major AP-PCR type was observed in 91% of the dogs (n=22); minor variations were frequently observed in these major types. Antibiograms of these commensal isolates were compared to antibiograms from 97 historical clinical isolates (1988-1992) obtained from cases of canine pyoderma. Resistance was most often observed to penicillin (64% and 55%) and tetracycline (38% and 38%) among the commensal and clinical isolates, respectively. The commensal isolates were significantly less resistant to erythromycin, clarithromycin, clindamycin, and trimethoprim/sulfamethoxazole. Our data suggests that differences in both genotype and antimicrobial susceptibility phenotypes exist among S. intermedius strains isolated from different anatomic sites from the same dog and supports the opportunistic nature of S. intermedius in canine infections.  相似文献   

7.
Poultry feed is at the start of the food safety chain in the "farm-to-fork" model, and might serve as a source of antimicrobial resistant bacteria present in poultry meat. Antimicrobial resistance was investigated in 1137 enterococci and 163 Escherichia coli strains recovered from 23 samples of commercial broiler feed and 66 samples of raw feeding materials taken over half a year timespan. Enumeration of enterococci and E. coli were also performed using traditional plating and fluorescent in situ hybridisation methods. Viable enterococci were detected in all feed samples and in 66% of samples of separate feed ingredients, while E. coli was present in 50% and 32% of feed and raw feeding materials, respectively. The median values (50th percentile) for plate and FISH counts for feeds were, respectively, 2.70 log CFU/g and 5.52 log cells/g for enterococci, and 0.15 log CFU/g and 6.00 log cells/g for E. coli. Among enterococci recovered from feed ingredients, resistance to rifampicin, erythromycin, nitrofurantoin, tetracycline, and ciprofloxacin was found in 59.8%, 21.6%, 21.2%, 18.0% and 6.9% of the isolates, respectively. A considerable proportion of the enterococci isolates obtained from broiler feed displayed resistance to tetracycline (69.1%), rifampicin (58.5%), erythromycin (52.9%) and nitrofurantoin (36.2%). Lower percentage of resistance was observed to chloramphenicol (4.6%), ciprofloxacin (3.9%), vancomycin (1.9%) and ampicillin (1.2%). Among E. coli recovered from feed ingredients and poultry feeds, resistance to ampicillin, tetracycline and streptomycin was found in 22.9%, 27.6% and 19.0% and in 22.4%, 41.4% and 17.0% of the isolates, respectively. These data show that feedstuffs and poultry feeds are extensively contaminated by resistant enterococci and, in a lesser extent, by E. coli, thus leading to their introduction in the farm environment.  相似文献   

8.
The occurrence of antimicrobial-resistant Staphylococcus intermedius strains was investigated in 13 dogs affected by deep pyoderma, their owners and 13 individuals without daily contact with dogs (control group). A total of 90 canine and 33 human S. intermedius isolates were typed by pulsed field gel electrophoresis (PFGE) to determine their possible identity. The occurrence of S. intermedius in dog-owners was significantly higher compared with the control group (Fisher's exact test, P=0.03), with S. intermedius being detected in seven dog-owners and in one individual not exposed to dogs. The results of the PFGE analysis showed that six out of 13 (46%) owners carried strains identical to those isolated from their dogs. Strains detected in both dogs and humans were resistant up to five different antimicrobial classes, including penicillins, fusidic acid, macrolides/lincosamides, tetracycline and chloramphenicol. Based on the results of this study, owners of dogs affected by deep pyoderma often carry multiple antimicrobial-resistant strains of S. intermedius occurring in their dogs. Independent of the direction and modalities of transmission, this finding raises questions concerning the possible transfer of resistance genes from canine S. intermedius to human pathogenic staphylococci.  相似文献   

9.
OBJECTIVE: To determine the methicillin-resistant profile of staphylococcal isolates from the skin of dogs with pyoderma. ANIMALS: 90 dogs with pyoderma. PROCEDURE: Staphylococci isolated from dogs with pyoderma were tested for susceptibility to methicillin by use of a standard disk diffusion test with oxacillin disks. The DNA extracted from the isolates was tested for the mecA gene that encodes the penicillin-binding protein 2a (PBP2a) by use of a polymerase chain reaction (PCR) assay. The expression of PBP2a was determined with a commercial latex agglutination assay. Species of staphylococcal isolates were identified by use of morphologic, biochemical, and enzymatic tests. RESULTS: Most of the isolated staphylococci were methicillin-susceptible, coagulase-positive Staphylococcus intermedius isolates. Whereas only 2 of 57 S. intermedius isolates were resistant to methicillin, approximately half of the isolates had the mecA gene and produced PBP2a. Staphylococcus schleiferi was the second most common isolate. Widespread resistance to methicillin was found among S. schleiferi isolates. More coagulase-negative S. schleiferi isolates were identified with mecA gene-mediated resistance to methicillin, compared with coagulase-positive S. schleiferi isolates. CONCLUSIONS AND CLINICAL RELEVANCE: The latex agglutination assay for the detection of PBP2a expression coupled with the PCR assay for the mecA gene may provide new information about emerging antimicrobial resistance among staphylococcal isolates.  相似文献   

10.
The prevalence of antibiotic resistant Escherichia coli in the rectal flora of 168 healthy dogs and 93 cats in the Brisbane area was investigated. Rectal swabs were plated on MacConkey agar with and without antibiotics, and 690 isolates confirmed as faecal E. coli were tested for resistance to tetracycline, streptomycin, chloramphenicol, ampicillin, neomycin, furazolidone and sulphanilamide. Resistant isolates were obtained from 101 (60%) of the dogs and 24 (26%) of the cats sampled. A high percentage of the isolates was resistant to tetracycline, streptomycin, ampicillin and sulphanilamide. Multiple resistance to 3 or more of the drugs was exhibited by the majority of isolates and a total of 31 different multiple resistance patterns was demonstrated. Of the 50 strains tested for transfer of resistance, 30 (60%) transferred some or all of their resistance determinants to an E. coli K12F - recipient.  相似文献   

11.
Antimicrobials effective against meticillin-resistant staphylococci are limited. Mupirocin is a topical antimicrobial used to treat bacterial skin infections. Novobiocin is an oral antimicrobial approved for treatment of staphylococcal upper respiratory infections in dogs. This study reports the in vitro activity of mupirocin and novobiocin on meticillin-susceptible (MSS) and resistant staphylococci (MRS) from healthy dogs and dogs with superficial pyoderma. Staphylococci were isolated from skin swabs at four sites on healthy dogs and from lesions on dogs with superficial pyoderma. Staphylococci were identified by morphology and by catalase and coagulase testing. Speciation and susceptibility testing were performed by the Dade Microscan (W. Sacramento, CA, USA). Meticillin resistance was confirmed by an oxacillin screen plate. Novobiocin and mupirocin susceptibilities were tested by disc diffusion. Staphylococci were cultured from 61 healthy dogs (17 MRS and 44 MSS) and 30 dogs with pyoderma (15 MRS and 15 MSS), with higher proportions of MRS isolates in dogs with pyoderma (P=0.038; χ(2) test). For mupirocin, 79.5% (35 of 44) MSS and 82.3% (14 of 17) MRS isolates from healthy dogs, and 100% (15 of 15) MSS and 86.6% (13 of 15) MRS isolates from dogs with pyoderma were susceptible (MSS, P=0.094; MRS, P=1.0; Fisher's exact test). For novobiocin, 95.4% (42 of 44) MSS and 52.9% (nine of 17) MRS isolates from healthy dogs and 93.3% (14 of 15) MSS and 80% (12 of 15) MRS isolates from dogs with pyoderma were susceptible (MSS, P=1.0; MRS, P=0.148; Fisher's exact test).  相似文献   

12.
The occurrence of antimicrobial resistance in generic Escherichia coli can serve as an indicator of the pool of resistance genes potentially available for transfer to pathogenic organisms. This study was conducted on 29 volunteer beef farms in Ontario to describe the prevalence and patterns of antimicrobial resistance in E. coli, and to describe changes in the prevalence of resistance during the feedlot stage of production. From the pooled fecal samples on 28 of the 29 farms, 31% of isolates from feedlots (n = 993) and 12% of isolates from cow-calf farms (n = 807) were resistant to one or more of 16 antimicrobials tested. No isolates were resistant to ceftriaxone, ciprofloxacin, gentamicin, or nalidixic acid, and < 1% of the pooled isolates were resistant to ceftiofur. Two percent of both feedlot and cow-calf isolates were resistant to > or = 5 antimicrobials. Cow-calf farms were at significantly lower risk than feedlots for having E. coli isolates that were resistant to streptomycin, sulfamethoxazole, and tetracycline. On average, the prevalence of sulfamethoxazole resistant E. coli isolates was significantly higher in calves than in cows. No resistance was observed to ceftriaxone or ciprofloxacin among isolates (n = 1265) obtained from individually sampled feedlot animals on 2 farms. Less than 1% of these isolates were resistant to gentamicin, nalidixic acid, and ceftiofur. From the individually sampled feedlot animals, resistance to streptomycin (on 1 farm), sulfamethoxazole, and tetracycline increased significantly from arrival to mid-point during the feeding period, and these levels persisted until market-readiness.  相似文献   

13.
Background – Canine pyodermas associated with meticillin‐resistant Staphylococcus spp. (MRS) have increased in prevalence over the past decade. Hypothesis/Objectives – To compare the prevalence of MRS isolation from dogs with superficial pyoderma at a primary care clinic (PCC) and those at a tertiary care facility (VMTH) in California, USA, and identify associated risk factors. Animals – Client‐owned dogs from the VMTH (80 dogs) and the PCC (30 dogs). Methods – Aerobic bacterial culture and antibiotic susceptibility were performed on swab specimens collected from dogs, and meticillin resistance was determined using microdilution methods according to Clinical and Laboratory Standards Institute guidelines. A mecA gene PCR assay was used to confirm meticillin resistance when possible. Results – Of 89 staphylococcal isolates from the VMTH, 34 (38.2%) were meticillin resistant. In 31 dogs, pyoderma persisted, and one or more follow‐up isolates were obtained. The species isolated and drug susceptibility changed unpredictably during treatment. Of 33 PCC isolates, nine (27.3%) were meticillin resistant. Multiple drug resistance was identified in 41 of 53 (77.3%) MRS isolates from the VMTH and five of nine from the PCC. The sensitivity and specificity of PCR for the detection of meticillin resistance was 34 of 39 (87%) and 86 of 87 (99%), respectively. Risk factors for meticillin resistance for both sites were antibiotic treatment within the last year (P = 0.001), and for VMTH, hospitalization of dogs within the last year (P = 0.001). Conclusions and clinical importance – The prevalence of meticillin resistance was not different between VMTH and PCC isolates (P = 0.29). Previous antimicrobial therapy was an important risk factor for the isolation of MRS at both sites.  相似文献   

14.
In a prospective study involving eight veterinary clinics during 1995 and 1996, samples from first-time and recurrent cases of canine pyoderma were collected by a needle technique. Three hundred and ninety-four staphylococci were isolated and their susceptibility to various antimicrobial drugs was assessed by a microdilution technique. Resistance to macrolides, lincosamides, fusidic add, tetracycline and streptomycin was significantly more common in isolates from the recurrent cases than from the first-time cases; 20 per cent of the isolates from the first-time cases were resistant to three or more of the antimicrobials tested, compared with 45 per cent of those from the recurrent cases. Coresistance between macrolide-lincosamides, tetracyclines and streptomycin was common. No resistance to penicillinase-stable beta-lactams was observed. A comparison with earlier studies indicated that there had been a marked increase in resistance during the previous five years.  相似文献   

15.
The prevalence of strains of Staphylococcus aureus, coagulase-negative (CN) staphylococci, Listeria monocytogenes, Escherichia coli, Enterococcus faecalis, E. faecium and Bacillus cereus, was investigated in 111 bulk milk samples. Staphylococcus aureus was isolated from 38 samples, CN staphylococci from 63 samples, E. coli from 49 samples, E. faecalis or E. faecium from 107 samples, and L. monocytogenes from two samples. Bacillus cereus was not found in any of the samples and three samples were free of any of the selected species. Sensitivity to the anti-microbial drugs amikacin, ampicillin, ampicillin + sulbactam, cephalothin (CLT), cephotaxime, clindamycin, chloramphenicol (CMP), co-trimoxazole, erythromycin (ERY), gentamicin, neomycin, norfloxacin, oxacillin, penicillin, streptomycin (STR), tetracycline (TTC) and vancomycin was tested using the standard dilution technique. Minimum inhibitory concentration (MIC) characteristics (MIC50, MIC90, MIC range) were determined for each microbial species. Resistance against one or more anti-microbial drugs was found in 93% of S. aureus, 40% of CN staphylococci, 73% of E. coli, 88% of E.faecalis, 55% of E.faecium, and one L. monocytogenes strain. Most of the strains, particularly enterococci, were resistant to STR, TTC, and ERY (MIC50 4 microg/ml). A high percentage of staphylococci were resistant to beta-lactam antibiotics. High resistance to CLT was found in 11 strains of E. coli (MIC 256 microg/ml) and strains resistant to CMP (MIC90 16 microg/ml) were detected. The highest numbers of resistance phenotypes were found in E. coil (16) and CN staphylococci (12). Eighteen identical resistance phenotypes were demonstrated in indicator bacteria (E. coli, E. faecalis, E. faecium) and pathogens (S. aureus, CN staphylococci) isolated from the same bulk milk sample. The obtained resistance data were matched against the herd owners' information on therapeutic use of the drugs. This confrontation could not explain the findings of strains resistant to ERY or CMP. Our findings are evidence of selection of resistant strains among not only pathogenic agents, but also among indicator bacteria which can become significant carriers of transmissible resistance genes.  相似文献   

16.
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.  相似文献   

17.
OBJECTIVE: To assess the strain heterogeneity of enrofloxacin-resistant Escherichia coli associated with urinary tract infections in dogs at a veterinary medical teaching hospital (VMTH). In addition, strains from other veterinary hospitals in California were compared with the VMTH strains to assess the geographic distribution of specific enrofloxacin-resistant E. coli isolates. DESIGN: Bacteriologic study. SAMPLE POPULATION: 56 isolates of E. coli from urine samples (43 isolates from dogs at the VMTH, 13 isolates from dogs from other veterinary clinics in California). PROCEDURES: Pulsed field gel electrophoresis was performed on 56 isolates of E. coli from urine samples from 56 dogs. All 56 isolates were tested for susceptibility to amoxicillin, chloramphenicol, enrofloxacin, tetracycline, trimethoprim-sulphamethoxazole, cephalexin, and ampicillin. Enrofloxacin usage data from 1994 to 1998 were obtained from the VMTH pharmacy. RESULTS: Several strains of enrofloxacin-resistant E. coli were collected from urine samples from the VMTH, and strains identical to those from the VMTH were collected from other veterinary clinics in California. For the isolates that did share similar DNA banding patterns, variable antibiotic resistance profiles were observed. CONCLUSIONS AND CLINICAL RELEVANCE: The increased occurrence of enrofloxacin-resistant E. coli from urine samples from dogs at the VMTH was not likely attributable to a single enrofloxacin-resistant clone but may be attributed to a collective increase in enrofloxacin resistance among uropathogenic E. coli in dogs in general.  相似文献   

18.
Background – Meticillin‐resistant staphylococci are significant pathogens in veterinary dermatology, yet longitudinal studies of the impact of routine antimicrobial therapy on emergence or resolution of resistance are lacking. Objectives – To determine the prevalence of meticillin‐resistant staphylococci on skin and carriage sites in dogs with bacterial pyoderma and evaluate the prevalence of meticillin‐resistant Staphylococcus pseudintermedius (MRSP) colonization after successful treatment of pyoderma. Animals – One hundred and seventy‐three dogs that presented to a dermatology referral service with pyoderma and 41 healthy control dogs. Methods – Skin, nasal and rectal swabs for bacterial culture were collected at the time of referral and after clinical resolution of the pyoderma. Meticillin resistance was confirmed by demonstration of penicillin binding protein 2a antigen. Results – Initially, skin cultures yielded MRSP in 70 (40.5%) dogs, meticillin‐resistant Staphylococcus aureus (MRSA) in three (1.7%) and meticillin‐resistant Staphylococcus schleiferi ssp. coagulans (MRSScoag) in five (2.9%). Samples collected from the nose and rectum (carriage sites) yielded MRSP in 59 (34.1%) dogs, MRSA in 11 (6.4%) and MRSScoag in seven (4.0%). One hundred and two dogs were available for follow‐up cultures after clinical cure. Of 42 dogs initially diagnosed with MRSP pyoderma, MRSP was isolated at follow‐up from skin in 19 (45.2%) and carriage sites in 20 (47.6%). Of 60 dogs that did not have MRSP pyoderma initially, MRSP was isolated post‐treatment from the skin in 17 (28.3%), and MRSP from carriage sites increased from 7.8% (initially) to 26.7% (P = 0.0022). Conclusions and clinical importance – Colonization by MRSP often persists after resolution of MRSP pyoderma. Acquisition of MRSP during treatment appears to be common.  相似文献   

19.
The species distribution, susceptibility to 19 antimicrobial agents and presence of selected genes encoding resistance to macrolides, streptogramins and tetracyclines were examined among 118 staphylococcal isolates from infections of poultry in Denmark. Isolates were identified using a combination of conventional biochemical testing and 16S rDNA sequencing. The most common species were Staphylococcus aureus (83), Staphylococcus hyicus (11), Staphylococcus xylosus (9) and Staphylococcus cohnii (6). The isolates were susceptible to most antimicrobials tested. A high frequency of S. aureus (30%) was resistant to ciprofloxacin. Only six (7%) S. aureus isolates and one Staphylococcus saprophyticus were penicillin resistant. Resistance to sulphamethoxazole was observed among 16 (19%) of S. aureus isolates and two coagulase negative staphylococci (CNS). Twenty (24%) of the S. aureus isolates were resistant to erythromycin and 19 of these isolates contained the ermA gene, whereas the remaining isolate contained the ermC gene. Eleven (48%) of the novobiocin resistant CNS were resistant to erythromycin and all these isolates contained the ermA gene. Two isolates identified as S. xylosus, were found to be resistant to streptogramins and both contained the vatB- and the vgaB-genes. Thirty-nine (47%) of the S. aureus isolates, three of nine S. hyicus and eight of the 23 novobiocin resistant CNS were tetracycline resistant and all contained the tet(K) gene. A single S. aureus isolate also contained the tet(M) gene. The present study showed a frequent occurrence of resistance to fluoroquinolones, tetracycline and macrolides among staphylococci isolated from broilers in Denmark, whereas the occurrence of resistance to other antimicrobial agents remains low. Similar genes, encoding resistance to erythromycin, tetracycline and streptogramins to those previously observed, were detected.  相似文献   

20.
Disk diffusion susceptibility tests were done on 1,178 clinical strains of coagulase-positive staphylococci (CPS) isolated from dogs during a 7-year period. Relative decreases of 7% to 33% were found in the percentages of CPS sensitive to 8 antimicrobics. Relative percentages of CPS sensitive to 9 other antimicrobics were increased or decreased less than 5%. Sensitivity to the beta-lactam antibiotics showed the least relative change. Regression analysis demonstrated that the greatest change in percentage sensitivity of CPS occurred to gentamicin and cephalothin and the least change occurred to penicillin and ampicillin. Recent canine clinical isolates of CPS, specifically identified as Staphylococcus intermedius (n = 109), were uniformly sensitive to novobiocin, amikacin, tobramycin, spectinomycin, and amoxicillin-clavulanic acid. Twenty-two isolates were also sensitive to 17 other antimicrobics. Eighty-seven isolates were resistant to 1 or more antimicrobics tested. Resistance was most common to sulfonamides, penicillin G, ampicillin, tetracycline, and streptomycin. Differences in susceptibility results between S intermedius and unspecified CPS were not statistically significant.  相似文献   

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