High diversity of coagulase negative staphylococci species in wild boars,with low antimicrobial resistance rates but detection of relevant resistance genes

This work was focused to determine the prevalence and the species diversity of coagulase-negative staphylococci (CoNS) in wild boars, and to study their antimicrobial resistance phenotype and genotype. Nasal samples of 371 wild boars from six Spanish regions were collected for CoNS recovery. The identification was performed by MALDI-TOF mass-spectrometry. Antimicrobial susceptibility for eight antimicrobial agents was studied by disc-diffusion method and the presence of 31 antimicrobial resistance genes by PCR.CoNS were detected in nasal samples of 136/371 animals tested (36.6%), and 161 isolates were obtained (1–3/animal); a high diversity of species was found (n = 17), with predominance of S. sciuri (n = 64), S. xylosus (n = 21) and S. chromogenes (n = 17). Among CoNS isolates, 22.4% showed resistance to at least one antimicrobial tested. Tetracycline-resistance phenotype was the most frequently detected (10.5%), generally mediated by tet(K) gene [associated or not with tet(L)]. Other relevant resistance genes were identified including unusual ones [mecA, erm(B), erm(F), mphC, erm(43), msr(A)/msr(B), lnu(A), dfrG, fexA, and cat_pC221].This is the first study in which CoNS isolates from wild boars are analysed. The knowledge of antimicrobial phenotype and genotype of CoNS in natural ecosystems is highly important since these staphylococcal species can act as vectors of relevant antimicrobial resistance mechanisms.     

Contagious impetigo in a dairy cattle herd

Abstract Impetigo and fürunculosis appeared in a dairy cattle herd in association with intensive showering of the lactating cows during the summer months. Heifers and dry cows in the same herd, as well as those in a neighbouring herd in the same village, which was not showered and served as a comparison herd, remained unaffected. Skin lésions declined with the termination of showering. Only six animals [three cows (7.3%) and three first-calving cows (20%)] had to be treated parenterally with antibiotics. Resumen En un rebafio de vacas de leche aparecieron cuadros de impetigo y fürunculosis asociados a las duchas frecuentes aplicadas durante los meses de verano a las vacas lactantes. Las novillas y vacas secas en el mismo rebaño, asi como las de un rebaño vecino de la misma localidad y que no recibian duchas fueron usadas como rebaño de comparación, no se vieron afectadas. Las lesiones cutáneas remitieron al dejar de aplicar las duchas. Tan solo en seis animales [tres vacas (7, 3%) y tres vacas en primer parto (20%)] fue necesario aplicar una terapia parenteral con antibióticos. [Yeruham, I., Elad, D., Perl, S., Nyska, A., Vishinsky, Y. Contagious impetigo in a dairy cattle herd (Impetigo contagioso en un rebaño de vacas de leche). Veterinary Dermatology 1996; 7 : 239–242.] Résumé Impétigo et füronculose se sont manifestés dans un troupeau laitier, en relation avec un douchage intensif des vaches allaitantes pendant les mois d'été. Les jeunes et les vaches taries du même troupeau, ainsi que celles d'un troupeau voisin du même village, non douchées et servant d'élément de comparaison, restèrent inaffectés. Les lésions cutanées ont régressé dês la cessation des douchages. Seuls six animaux (trois vaches-7, 3%-et trois vaches primipares-20%-) durent etre traités par antibiothérapie parentérale. [Yeruham, I., Elad, D., Perl, S., Nyska, A., Vishinsky, Y. Contagious impetigo in a dairy cattle herd (Impétigo contagieux dans un troupeau de vaches laitières). Veterinary Dermatology 1996; 7 : 239–242.] Zusammenfassung Eine Impetigo und Furunkulose trat bei einer Milchviehherde in Verbindung mit intensivem Abduschen bei den laktierenden Kühen während der Sommermonate auf. Färsen und trockenstehende Kühe in der selben Herde sowie die einer Nachbarherde im selben Ort, die nicht abgeduscht wurden und als Vergleichsgruppe dienten, blieben unverändert. Die Hautveränderungen reduzierten sich mit Beendigung des Abduschens. Nur sechs Tiere (drei Kühe (7, 3%) und drei Kalbinnen (20%)) mußten parenteral mit Antibiotika behandelt werden. [Yeruham, I., Elad, D., Perl, S., Nyska, A., Vishinsky, Y. Contagious impetigo in a dairy cattle herd (Ansteckende Impetigo bei einer Milchviehherde). Veterinary Dermatology 1996; 7 : 239–242.]     

葡萄球菌A蛋白协同凝集试验快速检测草鱼出血病病毒

本文报道葡萄球菌 A蛋白协同凝集(SPA COA)快速检测草鱼出血病病毒的方法以及对提纯病毒、染毒细胞内病毒和病鱼组织检测的初步结果。并对该方法进行了特异性和敏感性考核以及凝集物的电镜观察。该方法快速、特异、设备简单,适合基层单位检测草鱼出血病病毒,并有可能作为草鱼出血病疫苗质量鉴定的指标之一。     

混合菌种用于发酵香肠中的研究

用植物乳杆菌,葡萄球菌,汉逊酵母菌3个菌种作为发酵剂,通过耐盐和耐亚硝酸盐以及正交试验得到最佳生产条件为：植物乳杆菌：葡萄球菌：汉逊酵母为2：1：2,发酵温度30℃,接种量2%时是最优配比,发酵香肠时间为18小时。     

Staphylococcal and other Bacterial Species Associated with Intramammary Infections in Danish Dairy Herds

Four thousand six hundred forty– five quarter milk samples from 1179 cows from 20 commercial dairy herds were examined in order to determine the prevalence of bacterial species. A total of 859 isolates from 839 (18.1%) culture positive samples could be assigned to 34 different species and subspecies. Diagnostics of staphylococcal species was based on conventional procedures able to differentiate between all 36 species and subspecies presently acknowledged. Staphylococcus aureus was found in 10.2% of the samples and was the most common species isolated. Streptococcus dysgalactiae (1.6%) and Streptococcus uberis (1.4%) were the second and third most common species isolated. Seventeen different coagulase negative staphylococcal species (CNS) were found in 4.1% of the samples. The most frequently isolated CNS were S. epidermidis (1.3%), S. chromogenes (1.0%) and S. simulans (0.7%). Isolates of S. aureus were phage typed, and isolates of S. epidermidis were investigated by phage typing, antibiogram typing, and biotyping. A total of 378 (79.9%) isolates of S. aureus could be typed by phages, assigning them to 18 different phage types. However, 6 phage types accounted for 92.1% of the typable isolates. One to 2 phage types predominated within each herd. Eleven (18%) isolates of S. epidermidis could be typed by phages, assigning the isolates to 3 different types. Biotyping of S. epidermidis produced a total of 8 different types, the most common accounting for 29.5% of the isolates. A total of 6 different antibiogram types were observed among all isolates of S. epidermidis. Resistance towards penicillin (36.1%), tetracycline (9.8%) and streptomycin (9.8%), were recorded in the isolates of S. epidermidis. However, 35 (57.4%) of the isolates were susceptible to all 12 antibiotics tested.     

Coagulase negative staphylococci from ovine bulk-tank milk: Effects of the exposure to sub-inhibitory concentrations of disinfectants for teat-dipping

Teat-dipping is one of the most effective methods to prevent mammary infections in ruminants, including sub-clinical mastitis caused by coagulase-negative staphylococci (CoNS). Improper disinfectant application could expose microorganisms to sub-inhibitory concentrations leading to phenotypic variations. In this study, 12 chlorhexidine-digluconate (CHDG)-tolerant (of which 4 qac positive) and 12 benzalkonium chloride (BC)-tolerant (of which 7 qac-positive) CoNS isolates from ovine milk were exposed to sub-inhibitory concentrations of CHDG and BC, respectively. Changes in disinfectant susceptibility against BC and CHDG, antibiotic resistance against 12 antibiotics and biofilm production were then assessed for both groups. After CHDG stress, 67 % and 83 % of the CHDG-stressed isolates doubled their MICs for BC and CHDG, respectively and 2 qac-negative isolates showed a four-fold increase of their MBCs for CHDG. After BC stress, MICs for BC and CHDG doubled in 58 % and 83 % of the BC-stressed isolates, respectively, while one qac-positive isolate increased four-fold the MIC for BC. Cross-resistance to antibiotics was assessed by disc diffusion method. Some qac-positive isolates varied their resistance profile, while a blaZ-positive isolate showed a resistant phenotype against ampicillin only after the exposure to the disinfectant. As for qac-positive isolates, one CHDG-stressed and 2 BC-stressed increased their resistance to kanamycin and cefoxitin, respectively. The Congo Red Agar test was carried out to assess the in vitro slime production: all isolates were negative after stress. In conclusion, sub-inhibitory exposure to disinfectants may affect disinfectant and antibiotic susceptibility, the latter in particular for qac-positive isolates and those hosting unexpressed antibiotic resistance genes.     

20种中草药复配物对犬源葡萄球菌体外抑制作用的研究

为探究复方中草药对犬源葡萄球菌的体外抑制作用效果,将30种单味中草药配伍后得到20种复配物并制成水提物,采用二倍稀释法测定中草药复配物对犬源葡萄球菌的最低抑菌浓度(MIC),利用琼脂扩散法测定中草药复配物对犬源葡萄球菌的抑菌圈直径。结果表明,编号为15和16的中草药复配物对犬源葡萄球菌体外抑菌效果最好,最低抑菌浓度均为31.25mg/mL,抑菌圈直径分别为31.0mm和38.0mm,犬源葡萄球菌对这2个复方均表现为极敏;其他复方中草药对犬源葡萄球菌也呈现出不同程度的抑菌活性。研究结果为兽医临床筛选高效低毒的复方中草药制剂提供了科学依据。     

The Biochemical Activity of Enterotoxin and Non-Enterotoxin Producing Staphylococci

One hundred and sixty-nine staphylococcal strains of human origin have been tested for production of enterotoxin A, B or Ci, coagulase activity, DNase activity, typical growth on ETGP-agar, hemolysin production and the breakdown of mannitol under aerobic conditions. Very good correlation was observed between enterotoxin production and coagulase activity, in that 82 % of the enterotoxin producing strains also synthesized coagulase. The correlation between DNase activity and positive reaction in mannitol to enterotoxin production was also good (80 % of the enterotoxic strains produced both DNase and aerobic acid from mannitol). Of the enterotoxin producing strains 66 % hemolysed bovine erythrocytes and 61 % were ETGP-positive. However, the frequency of hemolysing respectively ETGP-positive but non-enterotoxin producing strains was very high, viz. 46 % respectively 32 %. It is concluded that enterotoxin production can not to a satisfactory degree of security be predicted by means of the other biochemical characters.