Presječno istraživanje prevalencije koagulaza negativnih izolata safilokoka, otpornih na meticilin, izdvojenih iz pasa u Litvi.

The aim of this study was to investigate the presence and frequency of methicillin-resistant coagulase negative staphylococci in dogs in Lithuania and to characterize them regarding antimicrobial resistance. In 2012-2013 clinical material was collected from 400 dogs. Three hundred samples from diseased dogs with different clinical conditions (dermatitis, otitis, wound infections, gastrointestinal and respiratory tract infections) as well as 100 samples from pure-breed bitches with reproductive disorders (pyometritis, metritis, partus praematurus), used as breeding animals in kennels, were selected. Twenty MRCNS isolates were obtained from 18 dogs out of 400 tested. All isolates harboured the mecA gene while the mecC (mecLGA251) gene was not found. Ten isolates were detected in vaginal samples of the bitches within 3 large kennels. The prevalence of MRCNS in dogs kept in households was 3.3 % i.e. significantly lower (P<0.01) than in dogs kept in large kennels (10 %). Ten different MRCNS species were detected with the highest prevalence for Staphylococcus haemolyticus. MRCNS isolates were resistant to macrolides (75 %) due to erm(C) and msrA genes, and to tetracycline (65 %) due to tet(K) and/or tet(M) genes. The rate of resistance to gentamicin was 50 % (attributed to aac(6′)-Ieaph(2”)-Ia, aph(3′)-IIIa), and to co-trimoxazole - 40 % (dfrG gene). One isolate of S. lentus harboured the dfrK gene. All isolates were susceptible to linezolid, daptomycin and vancomycin. This study revealed that breeding kennels might be a reservoir of MRCNS strains and may pose a risk for the spread of such strains during mating. The focus on the possible spread of multi-resistant S. haemolyticus between companion-animals and humans should be foreseen, as this species plays an important role in human infections as well.Cilj ovog istraživanja bio je ustanoviti prisutnost i učestalost koagulaza negativnih stafilokoka otpornih na meticilin (MRKNS) izdvojenih iz pasa u Litvi te odrediti njihovu otpornost na antimikrobne tvari. Klinički materijal bio je prikupljen iz 400 pasa 2012. i 2013. godine. Tri stotine uzoraka bilo je uzeto iz bolesnih pasa s različitim kliničkim znakovima (dermatitis, otitis, infekcije rana, infekcije probavnog i dišnog sustava) te 100 uzoraka iz kuja čistih pasmina s reprodukcijskim poremećajima (pyometritis, metritis, partus praematurus) upotrebljavanih za rasplod u štenarama. Od 400 pretraženih, 20 koagulaza negativnih izolata stafilokoka otpornih na meticilin bilo je izdvojeno iz 18 pasa. Svi izolati imali su gen mecA, dok gen mecC (mecLGA251) nije bio dokazan. Deset izolata bilo je izdvojeno iz uzoraka rodnice kuja iz triju velikih uzgoja. Prevalencija MRKNS u pasa držanih u domaćinstvima iznosila je 3,3 %, tj. bila je značajno manja (P<0,01) nego u pasa držanih u velikim uzgajivačnicama (10 %). Dokazano je 10 različitih vrsta koagulaza negativnih stafilokoka otpornih na meticilin s najvećom prevalencijom za vrstu Staphylococcus haemolyticus. MRKNS izolati bili su otporni na makrolide (75 %) zbog erm(C) i msrA gena i tetraciklin (65 %) zbog posjedovanja tet(K) i/ili tet(M) gena. Stopa otpornosti na gentamicin bila je 50 % (što se pripisuje genima aac(6′)-Ie-aph(2”)-Ia, aph(3′)-IIIa) i na ko-trimoksal – 40 % (gen dfrG). Jedan izolat vrste S. lentus imao je gen dfrK. Svi izolati bili su osjetljivi na linezolid, daptomicin i vankomicin. Ovo istraživanje pokazuje da uzgojne štenare mogu biti rezervoar sojeva MRKNS i mogu predstavljati rizik za širenje takvih sojeva za vrijeme parenja. Treba se usredotočiti na mogući prijenos višestruko otpornih sojeva vrste S. haemolyticus s kućnih ljubimaca na čovjeka s obzirom na to da ta vrsta ima važnu ulogu kao uzročnik infekcija u ljudi

Characterization of Staphylococcus pseudintermedius isolated from diseased dogs in Lithuania

The aim of this study was to characterize Staphylococcus pseudintermedius for its antimicrobial resistance and virulence factors with a special focus on methicillin-resistant (MRSP) strains isolated from sick dogs in Lithuania. Clinically sick adult dogs suffering from infections (n=214) and bitches with reproductive disorders (n=36) from kennels were selected for the study. Samples (n=192) from the 250 tested (76.8%) dogs were positive for Staphylococcus spp. Molecular profiling using the species-specific nuc gene identified 51 isolates as S. pseudintermedius (26.6% from a total number of isolated staphylococci) of which 15 isolates were identified as MRSP. Ten MRSP isolates were isolated from bitches with reproductive disorders from two large breeding kennels. Data on susceptibility of S. pseudintermedius to different antimicrobials revealed that all isolates were susceptible to vancomycin, daptomycin and linezolid. Two isolates (3.9%) were resistant to rifampicin. A high resistance was seen towards penicillin G (94.1%), tetracycline (64.7%) and macrolides (68.7%). Resistance to fluoroquinolones ranged from 25.5% (gatifloxacin) to 31.4% (ciprofloxacin). The most prevalent genes encoding resistance included blaZ, aac(6′)-Ie-aph(2″)-Ia, mecA, and tet(M). The Luk-I gene encoding a leukotoxin was detected in 29% of the isolates, whereas the siet gene encoding exfoliative toxin was detected in 69% of the S. pseudintermedius isolates. This report of MRSP in companion animals represents a major challenge for veterinarians in terms of antibiotic therapy and is a concern for both animal and public health

Effect of dietary vitamin D3 and 25-hydroxyvitamin D3 supplementation on plasma and milk 25-hydroxyvitamin D3 concentration in dairy cows

Milk enriched with vitamin D by supplementing dairy cow diets could provide a valuable dietary source of vitamin D, but information on the feasibility of this approach is limited. In the current study, the effects of supplementing dairy cows with either vitamin D3 or 25(OH) D3 over the transition/early lactation period on plasma and milk vitamin D concentrations were compared. Sixty dairy cows were randomly allocated to one of four dietary treatments from 14 days pre-calving to 56 days post-calving. Treatments were a control diet (Control) for both pre-calving and post-calving periods containing 0.625 mg/day vitamin D3; a pre-calving diet supplemented with 6 mg 25(OH) D3/day, but with a post-calving diet matching that of the control diet (25(OH) D3 pre-calving); the control diet pre-calving but with the post-calving diet supplemented with 2 mg vitamin D3/day (D3max), and the control diet pre-calving but with the post-calving diet supplemented with 1.5 mg 25(OH) D3/day (25(OH) D3 post-calving). No treatment effect on milk yield, composition or 25(OH) D3 concentration was observed. However there was an interaction of treatment and time for plasma 25(OH) D3 concentration; this increased within two weeks of supplementation for the 25(OH) D3 pre-calving treatment (peaking just after calving, 202 ng/ml), whereas that of the 25(OH) D3 post-calving group had a slower response following supplementation, continuing to increase at 56 days. There were correlations between plasma and milk 25(OH) D3 concentrations at days 4 and 14 of lactation, but not at later sampling times. The D3max treatment did not increase 25(OH) D3 concentration in plasma or milk. Overall, results from this study indicate that supplemental 25(OH) D3 is an effective means of enhancing dairy cow plasma 25(OH) D3 concentrations compared with vitamin D3 supplementation, but not necessarily milk concentrations

Phenotypical and genotypical antimicrobial resistance of coagulase-negative staphylococci isolated from cow mastitis

The objectives of this study were to determine the prevalence and antimicrobial resistance of coagulase-negative staphylococci (CNS) isolated from dairy cows with subclinical mastitis. Antimicrobial resistance in staphylococci were evaluated by breakpoint values specific to the species (EU-CAST). The presence of resistance-encoding genes was detected by multiplex PCR. A total of 191 CNS isolates were obtained. The CNS isolates were typically resistant to penicillin (67.4%), tetracyc-line (18.9%), and erythromycin (13.7%). CNS isolates (78.0%) were resistant to at least one antimicrobial compound, and 22.0% were multiresistant. The multiresistant isolates were predominantly Staphylococcus chromogenes (28.6%), Staphylococcus warneri (19%) and Staphylococcus haemolyticus (14.3%). According to MIC pattern data, multiresistant isolates showed the highest resistance (p<0.05) rates to penicillin (85.7%), tetracycline (66.7%), and erythromycin (48.2%), but all of them were sensitive to daptomycin, oxacillin, qiunupristin/dalfopristin, and vancomycin. S. chromogenes (9.5%), S. haemolyticus (4.8%), and S. capitis ss capitis (2.4%) strains were resistant to methicillin; their resistance to oxacillin and penicillin was more than 8 mg/l. A high rate of resistance to penicillin was linked to a blaZ gene found in 66.6% of the isolated multiresistant CNS strains. Resistance to tetracycline via the tetK (38.1%) gene and penicillin via the mecA (23.8%) gene were detected less frequently. Gene msrAB was responsible for macrolides and lincosamides resistance and detected in 28.6% of the CNS isolates. Antimicrobial resistance genes were identified more frequently in S. epidermidis, S. chromogenes, and S. warneri

Occurrence and characterization of livestock-associated methicillin-resistant Staphylococcus Aureus

Methicillin resistant Staphylococcus aureus causes a wide range of severe and economically-important diseases in humans and animals. Different types of MRSA are associated with different hosts but the transmission occurs between them. The aim of this study was to investigate possible spread of MRSA among livestock in Lithuania and to determine their types and antimicrobial resistance. Cattle (n=120), horses (n=120) pigs (n=160) and poultry (pooled samples, n=120) were tested for MRSA prevalence. From a total of 520 samples tested, 4 isolates of methicillin resistant Staphylococcus aureus (0.8 %) were identified. All isolates were obtained from the finisher pigs delivered from the same farm complex. Multiplex PCR demonstrated presence of mecA, nuc and 16S genes in all tested cultures. All MRSA isolates were identified as ST398. Sequencing of spa genes and SCCmec typing revealed that all strains belonged to the spa type t011 and SCCmec V. PFGE revealed two different clones among the isolates. Susceptibility testing revealed resistance to tetracycline in all MRSA isolates attributed to tetK and tetM genes. All tested isolates were resistant to erythromycin owing to the presence of ermB gene as well as resistances to azithromycin, clindamycin and quinupristin/dalfopristin. One isolate was resistant to trimethoprim/sulfamethoxazole and carried the resistance gene dfrK while the other isolate was resistant to the combination of amoxicillin and clavulanic acid. All of the isolates were susceptible to fluoroquinolones, cefotaxime, chloramphenicol, fosfomycin, fusidic acid, gentamicin, linezolid, vancomycin, mupirocin and teicoplanin

First report of swine-associated methicillin-resistant Staphylococcus aureus ST398 in Lithuania

During 2011, 160 nasal samples were taken from pigs on 8 different farms in Lithuania. Four methicillin-resistant Staphylococcus aureus (MRSA) isolates were obtained. The isolates were ST398, spa type t011 and SCCmec V and none carried the lukF/lukS genes. Strains were resistant to tetracycline, attributed to tetK and tetM genes, and to erythromycin owing to the ermB gene. One MRSA strain was resistant to trimethoprim/sulfamethoxazole and carried the dfrK gene. This is the first report on the presence and characteristics of livestock-associated MRSA isolated from pigs in Lithuania

Occurrence and characterization of livestock-associated methicillin-resistant Staphylococcus Aureus

Methicillin resistant Staphylococcus aureus causes a wide range of severe and economically-important diseases in humans and animals. Different types of MRSA are associated with different hosts but the transmission occurs between them. The aim of this study was to investigate possible spread of MRSA among livestock in Lithuania and to determine their types and antimicrobial resistance. Cattle (n=120), horses (n=120) pigs (n=160) and poultry (pooled samples, n=120) were tested for MRSA prevalence. From a total of 520 samples tested, 4 isolates of methicillin resistant Staphylococcus aureus (0.8 %) were identified. All isolates were obtained from the finisher pigs delivered from the same farm complex. Multiplex PCR demonstrated presence of mecA, nuc and 16S genes in all tested cultures. All MRSA isolates were identified as ST398. Sequencing of spa genes and SCCmec typing revealed that all strains belonged to the spa type t011 and SCCmec V. PFGE revealed two different clones among the isolates. Susceptibility testing revealed resistance to tetracycline in all MRSA isolates attributed to tetK and tetM genes. All tested isolates were resistant to erythromycin owing to the presence of ermB gene as well as resistances to azithromycin, clindamycin and quinupristin/dalfopristin. One isolate was resistant to trimethoprim/sulfamethoxazole and carried the resistance gene dfrK while the other isolate was resistant to the combination of amoxicillin and clavulanic acid. All of the isolates were susceptible to fluoroquinolones, cefotaxime, chloramphenicol, fosfomycin, fusidic acid, gentamicin, linezolid, vancomycin, mupirocin and teicoplanin