Bovine mastitis outbreak in Japan caused by methicillin-resistant Staphylococcus aureus New York/Japan clone

Abstract

Abstract. Many methicillin-resistant Staphylococcus aureus (MRSA) strains are multidrug-resistant; consequently, infectious diseases involving MRSA are recognized as troublesome diseases not only in human health care but also in animal health care. A bovine mastitis case caused by MRSA isolates of the New York/Japan clone (NJC), which occurred in Japan in 2005, was monitored in the current study. Isolates of the NJC are typical of hospital-acquired MRSA in Japan. The genetic backgrounds of these strains differ from those of bovine-associated S. aureus, which are typically of clonal complex (CC)97, CC705, and CC133. Moreover, the NJC isolates in this bovine outbreak possessed a β-hemolysin-converting bacteriophage and an immune evasion cluster, as found in the NJC isolates from humans, so it is possible that this clone was introduced into the dairy herd by a human carrier. Most bovine intramammary infections (IMIs) caused by the NJC isolates in our study were asymptomatic, and obvious clinical signs were recognized in only the first 3 infected cows. Of a total of 78 cows, 31 cows were MRSA carriers, and these carrier cows were detected by testing the milk of all lactating cows at 1-month intervals. These S. aureus carrier cows were culled or the infected quarter was dried off and no longer milked. Both IMI and mastitis caused by MRSA were completely eradicated after 5 months. Genotyping data suggested that exchanging of the staphylococcal cassette chromosome mec (the determining factor in methicillin resistance) occurred easily between MRSA and methicillin-sensitive S. aureus in the udders of carrier cows. This case study demonstrates an effective procedure against the spread of MRSA in a dairy herd, and highlights the risk of emergence of new MRSA strains in a dairy herd.

Prevalence and characterization of Panton-Valentine leukocidin-positive Staphylococcus aureus in bovine milk in Jabalpur district of Madhya Pradesh, India

“…It is plausible that these isolates could be of human origin. Recently, an outbreak and its successful management of bovine mastitis caused by New York/Japan (NJC) clone of Community Associated-MRSA were reported from Japan [ 18 ]. This study highlights the risk of emergence of new MRSA strains in dairy herd and an effective procedure against the spread of MRSA need to be based on molecular epidemiology studies.…”

Profiles of Staphyloccocus aureus isolated from goat persistent mastitis before and after treatment with enrofloxacin

“…Methicillin-resistant S. aureus (MRSA) is an important human and animal pathogen that is linked to several infections. Recently, the isolation of MRSA from dairy cows with mastitis [19][20][21], raw milk and dairy products has been reported worldwide [22,23], as well as in goats with mastitis [24,25].…”

Closely related methicillin-resistant Staphylococcus aureus isolates from retail meat, cows with mastitis, and humans in Japan

“…In Japan, MRSA have been detected in various food products, including chicken meat [ 12 ], [ 13 ], duck meat [ 13 ], meat products (the details regarding the type of meat product are unclear) [ 14 ], and bovine milk [ 15 ]. Furthermore, MRSA have been detected in livestock animals, including bovine mastitis [ 16 ] and nasal swabs of pigs [ 17 ], [ 18 ]. Although some MRSA related articles were reported in several origins (animals, meats, and humans), these MRSA isolates were not compared.…”