Bovine Intramammary Infections Caused by Coagulase-Negative Staphylococci May Persist Throughout Lactation According to Amplified Fragment Length Polymorphism-Based Analysis

Abstract

Persistence of coagulase-negative staphylococci (CNS) in intramammary infections during lactation was studied in a research dairy herd of University of Helsinki. Milk samples from 328 udder quarters of 82 dairy cows (30 primiparous, 52 multiparous) were collected 2 wk before calving, at calving, and every 4 wk thereafter until the end of lactation or until the cow left the herd. The CNS isolated from the milk samples were analyzed with the API Staph ID 32 (bioMérieux, Marcy l'Etoile, France) test (API) and genotyped using amplified fragment length polymorphism (AFLP) analysis. The AFLP patterns were used for similarity analysis between CNS isolates and for species identification. For the latter, AFLP patterns of CNS isolates and staphylococcal type strains were used as operational taxonomic units in numerical analysis. In addition, the somatic cell count (SCC) of the milk samples was measured during lactation. A CNS infection was considered persistent when isolates originating from the same quarter had identical AFLP patterns on at least 3 consecutive samplings. In total, 63 CNS infections were detected during lactation in 30 and 33 quarters in the first and later lactations, respectively. Twenty-nine of these infections persisted and 34 were transient. Most of the persistent infections lasted until the end of lactation. In 57 quarters, CNS infection was detected before calving, at calving, or both, but only half of these quarters were infected by CNS during subsequent lactation. The geometric mean of SCC in quarters during persistent CNS infection was 657,600 cells/mL, and the mean of SCC in quarters with transient CNS infection was 619,100 cells/mL. The median of SCC in quarters during persistent CNS infection was 355,400 cells/mL, and the median of SCC in quarters with transient CNS infection was 133,500 cells/mL. According to both the API test and AFLP results, Staphylococcus chromogenes and Staphylococcus simulans were the CNS species isolated most often. Identification results for API and AFLP corresponded in 71.9% of the isolates.

Udder quarter milk composition at different levels of somatic cell count in cow composite milk

“…In the presence of CNS, the most frequently found bacteria in our study, lactose percentages were lower and SCC was higher as compared to healthy quarters; however, the presence of the bacteria was not associated with any clinical signs of mastitis (Coulon et al, 2002). Taponen et al (2007) found the SCC in quarters infected with CNS to be rather low compared to other Gram-positive mastitis pathogens. However, the SCC were still about 10-fold higher in infected quarters compared to healthy quarters.…”

Occurence of Mastitis in Dairy Cows Situated in Marginal Parts of Slovakia

“…In the present study, most of the mastitis cases were caused by CoNS and Streptococcus spp. Similar results were obtained in Poland by M a l i n o w s k i et al [6] and in Finland by T a p o n e n et al [12].…”

“…The predominant contagious pathogens involved in bovine mastitis are Staphylococcus spp. (S. aureus and S. epidermidis) [9,12] [14,15].…”

Persistência De Staphylococcus Coagulase-Negativos Em Glândulas Mamárias De Ovelhas Com Mastite Subclínica Após O Tratamento Antimicrobiano À Secagem

“…Taponen et al (21) relataram a persistência de SCN no decorrer da lactação no interior da glândula mamária de ovelhas. No presente estudo, em duas ovelhas ("12" e "16") clones de S. simulans podem ter permanecido na metade mamária de uma mesma ovelha após transcorrido todo o período seco e não somente durante a lactação.…”