Prevalence and Characteristics of Staphylococcus aureus in Connecticut Swine and Swine Farmers

This study explores the characteristics of Staphylococcus aureus (S. aureus) in swine and their human handlers in a convenience sample of 35 farms in Connecticut. Husbandry practices are clearly different from better‐known concentrated animal feeding operations (CAFOs) with less intensive rearing conditions. Nasal samples were collected from 263 pigs and nine humans on 35 farms during the 2010 rearing season. Samples were analysed using established microbiology methods, and resulting methicillin‐sensitive (MSSA) and resistant (MRSA) isolates were typed by pulsed‐field gel electrophoresis (PFGE) and spa typing. PCR was used to detect the presence of the Panton‐Valentine Leukocidin (PVL) gene, a cytotoxin usually associated with CA‐MRSA infection. A farm assessment form and questionnaire were used to obtain the information about husbandry practices and human exposure risk, respectively. Staphylococcus aureus colonized swine and humans were found in 51% (18/35) of the farms sampled at a rate of 30% (85/259) and 22% (2/9), respectively. Eight pigs and two humans were MRSA positive on five farms. MRSA in swine was related to healthcare‐associated (HA), community‐associated (CA) or livestock‐associated (LA) MRSA strains, whereas humans were colonized with HA‐MRSA. On the basis of spa typing, there was evidence of human–animal transmission thereby signifying humanosis/reverse zoonoses. The PVL gene was found in 88% (7/8) of MRSA swine isolates, the first time this gene has been seen in colonized pigs sampled on US farm. MSSA isolates belonged to six spa types: t337 (41%), t034 (12%), t334 (12%), t4529 (12%), t8760 (18%) and t1166 (6%) including LA strains. This is the first time spa type t8760 has been reported and the only MSSA with the PVL gene. In summary, MRSA including LA strains (LA‐MRSA) can be found on small farms with different husbandry practices from CAFOs, suggesting that preventive measures for zoonotic MRSA infection should address a range of animal production.     

不同抗生素替代品组合对断奶仔猪生长性能、腹泻及抗氧化能力的影响

为研究不同替代品组合替代饲用抗生素的可行性,选取240头、（28±3）日龄的"杜×长×大"断奶仔猪,随机分为5组：对照组（基础日粮）、抗生素组（基础日粮＋75 mg/kg金霉素＋40 mg/kg杆菌肽锌＋100 mg/kg喹乙醇）、处理1组（基础日粮＋2 000 mg/kg发酵中草药）、处理2组（基础日粮＋500 mg/kg丁酸梭菌＋1 000 mg/kg三丁酸甘油酯）及处理3组（基础日粮＋450 mg/kg博落回散＋800 mg/kg无水甜菜碱）。每组设5个重复,每重复12头。试验期32 d。在试验第14、32天时,每重复随机选取1头仔猪,前腔静脉采血,分离血浆,测定其生长性能、腹泻指数及血液抗氧化指标。试验结果表明：①1~14 d时,相比对照组,处理3组可显著提高平均日采食量（ADFI）、平均日增重（ADG）（P < 0.05）,显著降低料重比（F/G）（P < 0.05）。15~32 d时,处理3组的料重比比对照组和抗生素组极显著降低（P < 0.01）。1~32 d时,与抗生素组相比,处理3组料重比显著降低（P < 0.05）。②1~14 d时,与对照组相比,处理3组腹泻指数极显著降低（P < 0.01）。在15~32和1~32 d时,处理2组、3组的腹泻指数均极显著低于对照组（P < 0.01）;处理3组与抗生素组腹泻指数差异不显著（P > 0.05）,但均比对照组有一定程度降低（P > 0.05）。③与对照组和抗生素组相比,处理3组14 d时的血浆总超氧化物歧化酶（T-SOD）活性、谷胱甘肽（GSH）含量显著或极显著增加（P < 0.05;P < 0.01）,丙二醛（MDA）、过氧化氢（H₂O₂）含量极显著或显著降低（P < 0.01;P < 0.05）;32 d时GSH含量极显著增加（P < 0.01）,MDA含量极显著或显著降低（P < 0.01;P < 0.05）。比较各试验处理,日粮中添加博落回散（450 mg/kg）＋无水甜菜碱（800 mg/kg）能降低断奶仔猪的料重比,提高抗氧化性能,减少腹泻,效果优于其他组合,可作为抗生素替代品在仔猪饲料中使用。     

无抗条件下从肠道健康方面控制断奶仔猪腹泻的策略

在过去的几十年里,抗菌化合物已被用于预防亚临床和临床疾病,促进断奶仔猪生长等方面。但人们越来越关注细菌耐药性、耐药菌株及其相关基因对人类健康的潜在影响。欧盟从2006年1月1日起禁止在猪和家禽生产中使用抗生素作为生长促进剂。此外,高锌和高铜等矿物质也具有促生长作用,但饲料中添加高锌、高铜会严重污染环境。因此,在不使用抗生素的条件下,有必要制定相应的营养和饲喂策略,以便控制与断奶过渡有关的问题。本文综述改善胃肠道结构、功能,促进断奶后仔猪生长的营养策略,重点介绍益生菌、益生元、有机酸、微量元素来源及水平。     

Antimicrobial associated diarrhoea in the horse. Part 1: Overview,pathogenesis and risk factors

Antimicrobial associated diarrhoea (AAD) is the most commonly recognised adverse effect of antimicrobial treatment in horses, although its incidence is probably low given the frequency of antimicrobial administration. Clinical signs vary from transient self‐limiting diarrhoea to rapidly fatal toxic enterocolitis. AAD prolongs the duration of hospitalisation, increases diagnostic and therapeutic costs, and was associated with a lower case survival rate than other types of acute diarrhoea in one study. Virtually all antimicrobials have been implicated in AAD, but some pose a greater risk than others.     

百饲康(复合微生物制剂)对仔猪生长性能的影响

试验基于研究百饲康(以丁酸梭菌为主的益生菌)在仔猪上的应用效果设计,选取三元杂(杜×长×大)仔猪,在三个猪场分别进行饲养实验。通过平均增重、料肉比、腹泻率等指标探讨百饲康(复合微生物制剂)的作用效果。结果表明:仔猪产房(0～28日龄)及保育猪(29～60日龄),配合饲料中添加0.05～0.1%的百饲康,与抗生素组相比,提高了饲料转化率,腹泻率显著降低,肠道内乳酸菌、丁酸梭菌含量显著提高,pH值降低,大肠杆菌含量显著降低。     

粪肠球菌替代抗生素对断奶仔猪生长性能、腹泻率、血液生化指标和免疫器官的影响

本试验在断奶仔猪饲粮中添加不同水平的粪肠球菌,研究其替代抗生素对断奶仔猪生长性能、腹泻指数和腹泻率、血液生化指标以及免疫器官的影响。选取120头(28±2)日龄平均体重为(7.60±0.81)kg的"杜×长×大"断奶仔猪,随机分为5组,每组6个重复(公母各占1/2),每个重复4头,每个重复为1圈。对照组饲喂基础饲粮,抗生素组在基础饲粮中添加100mg/kg硫酸黏菌素和400 mg/kg杆菌肽锌,3个粪肠球菌组分别在基础饲粮中添加40、200和1 000 mg/kg粪肠球菌,试验期31 d。试验结果显示:1)在1~14 d,饲粮中添加抗生素和粪肠球菌对断奶仔猪的平均日采食量(ADFI)、平均日增重(ADG)以及料重比(F/G)无显著影响(P0.05)。在15~31 d,与对照组和抗生素组相比,200和1 000 mg/kg组可极显著提高ADFI和ADG(P0.01)。在1~31 d,与对照组相比,200和1 000 mg/kg组的ADFI均极显著提高(P0.01),而ADG分别显著和极显著增加(P0.05和P0.01);与抗生素组相比,1 000 mg/kg组可极显著提高ADFI(P0.01),而200和1 000 mg/kg组的ADG分别显著和极显著增加(P0.05和P0.01)。2)在1~14 d,与对照组相比,40 mg/kg组的腹泻指数和腹泻率显著降低(P0.05)。在15~31 d和1~31 d,与对照组和抗生素组相比,40和1 000 mg/kg组均可在一定程度上降低腹泻率(P0.05)。3)与对照组相比,粪肠球菌可以显著提高血液中总蛋白含量(P0.05),其中200和1 000 mg/kg组达到极显著水平(P0.01),且这2组分别可以显著和极显著提高球蛋白含量(P0.05和P0.01)。与抗生素组相比,200和1 000 mg/kg组可以显著提高总蛋白含量(P0.05)。与对照组相比,抗生素组和1 000 mg/kg组的白球比显著降低(P0.05),另外,抗生素组血液中谷丙转氨酶和谷草转氨酶活性显著降低(P0.05),200 mg/kg组的谷丙转氨酶活性显著降低(P0.05)。4)与对照组相比,1 000 mg/kg组的肝脏重量和脾脏指数有一定程度的提高(P0.05),与抗生素组相比,200和1 000 mg/kg组可显著提高肝脏重量(P0.05)。结果表明,饲粮中添加粪肠球菌可改善断奶仔猪的生长性能(饲喂15~31 d),降低腹泻率,提高仔猪免疫力,其中添加量为1 000 mg/kg时效果最好。     

The prevalence of isospora suis and strongyloides ransomi in suckling piglets in the Netherlands

Summary

Faecal samples from suckling piglets from 113 litters on 25 farms in the Netherlands were examined to study the prevalence of gastrointestinal parasites, in particular Strongyloides ransomi and Isospora suis. S. ransomi was not found but I. suis was demonstrated in 17 of the 25 farms and in 41 out of 77 litters of these farms (53%). No other parasites were found. On the basis of these results, a longitudinal study on the incidence and significance of I. suis was performed on 10 farms (5 litters/farm). I. suis was found on 9 out of 10 farms and in 56% of the litters. Farms differed in infection levels, measured as the numbers of patent litters, and in the onset of patency. Other parasites were only found in faecal samples from the sows and from farrowing pens. These were, in order of prevalence, Balantidium coli, Ascaris suum, Eimeria spinosa, E. debliecki and E. suis.     

Identical genotypes of community‐associated MRSA (ST59) and livestock‐associated MRSA (ST9) in humans and pigs in rural China

This study investigated the prevalence of MRSA in samples taken in households, with and without backyard pigs in villages in a rural area of Shandong Province, China. Community‐associated MRSA and livestock‐associated MRSA, belonging to ST59 and ST9, respectively, were identified in both humans and pigs. The genotypic and phenotypic comparison of isolates indicates that bidirectional transmission of MRSA has occurred between humans and pigs in the villages.     

Antimicrobial associated diarrhoea in the horse. Part 2: Which antimicrobials are associated with AAD in the horse?

Almost all oral and parenterally administered antimicrobials have been linked with antimicrobial associated diarrhoea (AAD) in both man and horses, although some antimicrobials clearly pose a higher risk.     

Histology,histochemistry and ultrastructure of the nasopharyngeal tonsil of the buffalo (Bubalus bubalis)

The light microscopic appearance and ultrastructure of the nasopharyngeal tonsil (tonsilla pharyngea), collected from 12 adult buffaloes of local mixed breed, were explored for the distribution of different types of epithelia, lymphoid tissue and high endothelial venules. The tonsillar mucosa was lined by pseudostratified columnar ciliated epithelium having goblet cells. The respiratory epithelium associated with the underlying lymphoid tissue formed the lymphoepithelium. The epithelium was further modified into follicle‐associated epithelium (FAE) characterized by reduced epithelial height, presence of a few dome‐shaped cuboidal cells equivalent of the M‐cells and absence of goblet and ciliated cells. The lymphoid tissue was distributed in the form of isolated lymphoid cells, diffuse lymphoid tissue and lymphoid follicles, mainly distributed within the propria‐submucosa along with the sero‐mucous glandular tissue. The goblet cells of the respiratory epithelium and the acinar cells contained different mucopolysaccharides. Scanning electron microscopy of the surface mucosa demonstrated a dense mat of cilia, island‐like arrangement of microvillus cells, M‐cells and a few brush‐like cells. The transmission electron microscopy revealed the different cell organelles of the respiratory epithelium and the FAE. Lymphocyte migration via the high endothelial venules in the propria‐submucosa was also observed.     

Changes in diarrhea,nutrients apparent digestibility,digestive enzyme activities of weaned piglets in response to chitosan‐zinc chelate

A total of 120 weanling barrows weighing 6.11 ± 0.20 kg were randomly allotted to four treatments with three replications (i.e. pen) of ten piglets per replicate. Pigs were received corn‐soybean basal diet (control) or the same basal diet supplemented with the following sources of zinc: (i) 100 mg/kg of Zn as ZnSO₄; (ii) 100 mg/kg of Zn as chitosan‐Zn chelate (CS‐Zn); and (iii) 100 mg/kg of Zn as ZnSO₄ mixed with chitosan (CS + ZnSO₄). The results showed that CS‐Zn could highly improve average daily gain and average daily feed intake than those of ZnSO₄ or CS+ ZnSO₄ (P < 0.05). The pigs fed dietary CS‐Zn had lower diarrhea incidence and higher apparent digestibility of crude protein than those of the pigs fed dietary ZnSO₄ (P < 0.05). The protease activities in duodenal content of the pigs receiving CS‐Zn diets was higher than that of the pigs fed dietary ZnSO₄ or CS + ZnSO₄ (P < 0.05). The amylase activity in duodenal content of the pigs fed dietary CS‐Zn was higher than that of the pigs receiving ZnSO₄ diets or basal diets (P < 0.05). These results indicated that dietary CS‐Zn showed different bioactivities from ZnSO₄ or CS + ZnSO₄ in reducing the incidence of diarrhea, improving activities of digestive enzymes and growth performance of weaned pigs.     

An overview of calf diarrhea - infectious etiology,diagnosis, and intervention

Calf diarrhea is a commonly reported disease in young animals, and still a major cause of productivity and economic loss to cattle producers worldwide. In the report of the 2007 National Animal Health Monitoring System for U.S. dairy, half of the deaths among unweaned calves was attributed to diarrhea. Multiple pathogens are known or postulated to cause or contribute to calf diarrhea development. Other factors including both the environment and management practices influence disease severity or outcomes. The multifactorial nature of calf diarrhea makes this disease hard to control effectively in modern cow-calf operations. The purpose of this review is to provide a better understanding of a) the ecology and pathogenesis of well-known and potential bovine enteric pathogens implicated in calf diarrhea, b) describe diagnostic tests used to detect various enteric pathogens along with their pros and cons, and c) propose improved intervention strategies for treating calf diarrhea.     

Efficacy of two low-dose oral tylosin regimens in controlling the relapse of diarrhea in dogs with tylosin-responsive diarrhea: a prospective,single-blinded,two-arm parallel,clinical field trial

Background

Despite its wide acceptance as a treatment for canine chronic enteropathies, the macrolide antibiotic tylosin lacks official oral dosage recommendations. Not even textbooks share consensus about the dose; daily recommendations vary from 25 to 80 mg/kg and dosing intervals from one to three times daily.The objective of this prospective, single-blinded, two-arm parallel, clinical field trial was to determine whether doses of 5 mg/kg or 15 mg/kg tylosin administered orally once daily for seven days would have a similar effect on fecal consistency in diarrhea relapses to that of a 25 mg/kg dose of tylosin administered once daily for seven days, a dosage that has proved effective in controlling canine tylosin-responsive diarrhea (TRD). A further objective was to compare the efficacy of the 5 mg/kg and 15 mg/kg tylosin dosages. Fifteen client-owned dogs diagnosed with TRD that had responded to a dose of 25 mg/kg tylosin once daily for seven days were enrolled in the study. After a relapse of diarrhea the dogs were allocated into two groups receiving tylosin orally in doses of either 5 mg/kg or 15 mg/kg once daily for seven days. The owners were blinded to the dosage. The elimination of diarrhea was the main criterion in assessing treatment success. The mean fecal consistency score of the last three treatment days for all dosages, including 25 mg/kg, as evaluated by the owners according to a standardized fecal scoring system, served as the primary outcome measures.

Results

All eight dogs responded to the 5 mg/kg dose, and six of seven dogs responded to the 15 mg/kg dose. The mean fecal consistency scores at the 25 mg/kg tylosin dosage were no significantly different from scores at the 5 mg/kg or 15 mg/kg tylosin dosages (P = 0.672, P = 0.345).

Conclusions

Interestingly, 14/15 (93%) of the dogs responding to a dose of 25 mg/kg tylosin once daily for seven days also responded to the lower dosages at diarrhea relapse. The data indicate that a suitable dose of tylosin for treating diarrhea relapse in canine TRD could be as low as 5 mg/kg once daily for seven days.     

Serogroups, atypical biochemical characters, colicinogeny and antibiotic resistance pattern of Shiga toxin-producing Escherichia coli isolated from diarrhoeic calves in Gujarat, India

This study was designed to investigate the antibiotic resistance, colicinogeny, serotyping and atypical biochemical characteristics of 41 Shiga toxin-producing Escherichia coli (STEC) strains detected using polymerase chain reaction from 90 E. coli strains isolated from 46 diarrhoeic calves. The STEC strains belonged to 14 different serogroups. Seventeen per cent of the STEC strains carried the eaeA gene while 14.28% of the 49 non-STEC strains were eaeA positive. Twenty eight (68.29%) of the 41 STEC strains were rhamnose non-fermentors. All the STEC strains revealed resistance to at least three of the antibiotics tested. 100% resistance was found against kanamycin and cephalexin followed by cephaloridine, enrofloxacin, amikacin, ampicillin, tetracycline, ceftiofur, ciprofloxacin, colistin and co-trimoxazole. Eighteen (44%) of the STEC strains produced colicin and all these colicinogenic strains were resistant to three or more antibiotics. Eleven STEC strains (26.82%) showed urease activity. The results of this study suggest that diarrhoeic calves are an important reservoir of STEC strains that are potentially pathogenic for farm animals and humans. Moreover, rhamnose fermentation, colicinogeny and atypical biochemical behaviour, such as urease activity, may serve as important markers or diagnostic tools for epidemiological surveys to trace the source of infection in disease outbreaks.