METHODS: A structured questionnaire is used to survey a convenience sample of 132 Egyptian cattle beef and dairy farms suffering emerged epidemics to identify commonly used disinfection process, disinfectant types, disinfectants frequency, and rate of use. One hundred and thirty-two water samples were collected for microbiological analysis to obtain water bacterial profile and testing resistance to chlorine. Statistical analysis was performed to identify the level of association between microbial profile and presence of chlorine-resistant strains in each farm with used disinfection, disinfectant types, and rate of use in these farms.
RESULTS: A wide range of disinfectant types used for variable purposes inside cattle farms with a different frequency of use and the highest percent of farms 25.8% use 4-5 types of disinfectants, followed by 25% of farms use two types, then 18.9% use three types. Microbial profile of water samples revealed isolation of E. coli, Streptococcus faecalis, Pseudomonas aeruginosa, Klebsiella spp., Proteus spp., Salmonella spp., Enterobacter spp., Citrobacter spp., Shigella flexneri, Serratia marcescens, and Yersinia enterocolitica in percent (98.5, 97.7, 97.7, 76.5, 66.7, 36.4, 78.8, 74.2, 30.3, 29.5, and 14.4% of cattle farms, respectively), from which five E. coli, four Salmonella, four Pseudomonas, two Klebsiella, and four Streptococcus strains expressed chlorine resistance. Statistical analysis showed weak to moderate correlation (rho 0.15-0.46) between bacterial profile strains count and presence of resistant strains with different farm disinfection, disinfectant types, and rate of use. Experimental evaluation of the bactericidal effect of the eight selected disinfectants on the chlorine-resistant isolated strains revealed that peroxymonosulfate killed 19/19 isolated strains/15 min contact time, and quaternary ammonium compounds killed only 3/19 strains/15 min contact time. The qacE resistance gene was detected in 3/4 isolated chlorine-resistant E. coli strains.
CONCLUSIONS: Drinking water microbial profile strains and resistance to disinfectants are widely varied in cattle farms, and this variance depends on critical factors among which the disinfection process types used disinfectant types and frequency of disinfectants use or change.
方法:使用结构化问卷对132个埃及牛牛肉和奶牛场进行了调查,以确定常用的消毒过程,消毒剂类型,消毒剂频率,和使用率。收集了一百三十两个水样进行微生物分析,以获得水细菌谱并测试对氯的抗性。进行了统计分析,以确定每个使用消毒的农场中微生物谱与耐氯菌株的存在之间的关联水平,消毒剂类型,以及这些农场的使用率。
结果:在使用频率不同的养牛场内用于可变目的的各种消毒剂类型,最高比例为25.8%的农场使用4-5种消毒剂,其次是25%的农场使用两种类型,然后18.9%使用三种类型。水样的微生物分布显示大肠杆菌的分离,粪链球菌,铜绿假单胞菌,克雷伯菌属。,变形杆菌。,沙门氏菌属。,肠杆菌属。,柠檬酸杆菌属。,福氏志贺氏菌,粘质沙雷菌,和小肠结肠炎耶尔森氏菌百分比(98.5、97.7、97.7、76.5、66.7、36.4、78.8、74.2、30.3、29.5和14.4%的牛场,分别),来自其中的五种大肠杆菌,四个沙门氏菌,四个假单胞菌,两个克雷伯菌,4株链球菌均表现出氯抗性。统计分析表明,细菌谱菌株计数与不同农场消毒的耐药菌株之间存在弱至中度相关性(rho0.15-0.46),消毒剂类型,和使用率。选定的8种消毒剂对耐氯分离菌株的杀菌效果的实验评估表明,过氧单硫酸盐杀死19/19分离菌株/15分钟接触时间,和季铵化合物仅杀死3/19菌株/15分钟接触时间。在3/4分离的耐氯大肠杆菌菌株中检测到qacE抗性基因。
结论:养牛场的饮用水微生物菌株和对消毒剂的抗性差异很大,这种差异取决于关键因素,其中使用消毒剂的消毒过程类型和使用或改变消毒剂的频率。