Incidence of clinical mastitis and distribution of pathogens on large Chinese dairy farms

Abstract

Knowledge of the incidence of clinical mastitis (CM) and the distribution of pathogens involved is essential for development of prevention and control programs as well as treatment protocols. No country-wide study on the incidence of CM and the distribution of pathogens involved has been conducted in China. Core objectives of this study were, therefore, to determine the cumulative incidence of CM and the distribution of pathogens causing CM on large Chinese (>500 cows) dairy farms. In addition, associations between the distribution of CM pathogens and bedding materials and seasonal factors were also investigated. Bacterial culture was done on a total of 3,288 CM quarter milk samples from 161 dairy herds (located in 21 provinces) between March 2014 and September 2016. Additional data, including geographical region of herds, herd size, bedding types, and number of CM cases during the last month, were also recorded. Mean cumulative incidence of CM was 3.3 cases per 100 cows per month (range = 1.7 to 8.1). The most frequently isolated pathogens were Escherichia coli (14.4%), Klebsiella spp. (13.0%), coagulase-negative staphylococci (11.3%), Streptococcus dysgalactiae (10.5%), and Staphylococcus aureus (10.2%). Streptococcus agalactiae was isolated from 2.8% of CM samples, whereas Streptococcus uberis were isolated from 2.1% of samples, and 15.8% of 3,288 samples were culture-negative. Coagulase-negative staphylococci, E. coli, and other Enterobacter spp. were more frequently isolated in the northwest than the northeast or south of China. Streptococcus dysgalactiae, other streptococci, and Strep. agalactiae were more frequently isolated in winter (October-March), whereas E. coli and Klebsiella spp. were mostly isolated in summer (April-September). Streptococcus dysgalactiae was more often isolated from CM cases of herds using sand bedding, whereas Klebsiella spp. and other streptococci were more common in herds using organic bedding. The incidence of CM and distribution of pathogens differed among herds and better mastitis management is needed. Furthermore, geography, bedding materials, and season should be included when designing mastitis control and prevention schemes for Chinese dairies.

Antimicrobial resistance profiles of 5 common bovine mastitis pathogens in large Chinese dairy herds

“…Upon arrival at the laboratory, all frozen samples were thawed at room temperature. Microbiological procedures were conducted as described by Ali et al (2017) and Gao et al (2017). Briefly, 10 μL of milk from each sample was plated onto a tryptic soy agar (Beijing Aoboxing Biotechnology Co. Ltd., Beijing, Beijing 3 5 2 2 2 4 3 7 3 6 Guangdong 2 6 1 8 3 6 3 9 2 4 Hebei 6 13 7 31 5 20 5 24 13 35 Heilongjiang 2 44 2 32 14 39 6 27 4 9 Henan 2 3 2 6 5 8 2 4 2 6 Liaoning 2 12 ----2 5 3 13 Inner Mongolia 6 13 6 22 7 15 5 18 10 32 Shandong 1 1 2 4 4 6 2 6 4 13 Shanxi 2 6 1 2 1 3 --2 8 Tianjin --------2 4 Total 26 103 23 107 41 101 28 100 45 130 1 Number of clinical mastitis isolates.…”

8‐Methoxypsoralen protects bovine mammary epithelial cells against lipopolysaccharide‐induced inflammatory injury via suppressing JAK/STAT and NF‐κB pathway

“…There are two types, clinical and subclinical mastitis. In most cases, an infection with Gram‐negative bacteria, such as E. coli , can often cause clinical mastitis, and Gram‐positive bacteria, such as Staphylococcus aureus , are involved in subclinical mastitis infection …”

“…In most cases, an infection with Gramnegative bacteria, such as E. coli, can often cause clinical mastitis, and Gram-positive bacteria, such as Staphylococcus aureus, are involved in subclinical mastitis infection. 19,20 Mammary epithelial cells, the most numerous cells in the mammary gland, are important for the early defense against intramammary pathogens. They constitute a physical barrier and induce the secretion of inflammatory mediators in response to invading pathogens.…”

Production system innovation to ensure raw milk safety in small holder economies: the case of dairy complex in China

“…However, raw milk spoilage and contamination has been an important issue because consumers cannot tell with information asymmetry between them and producers along the prolonged supply chain. Several pathogens have been identified in milk that may cause health issues (Gao et al., ), and many recent milk contamination cases have been documented worldwide (Jamali et al., ). It is very important to ensure the safety of raw milk to provide safer dairy products to consumers.…”