Antimicrobial activity of marine sponges against coagulase-negative staphylococci isolated from bovine mastitis Marinella Silva Laport a, *, Palloma Rodrigues Marinho a , Olinda Cabral da Silva Santos a , Paula de Almeida a , Maria Teresa Villela Romanos a , Guilherme Muricy b , Maria Aparecida Vasconcelos Paiva Brito c , Marcia Giambiagi-deMarval a a Instituto de Microbiologia Paulo de Go ´es, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, 373, Cidade Universita ´ria, 21941-590, Rio de Janeiro, Brazil b Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, 20940-040, Rio de Janeiro, Brazil c Embrapa Gado de Leite, Juiz de Fora, MG, Brazil 1. Introduction Bovine mastitis is an inflammation of the mammary glands of cows and is usually caused by microbial infection that affects milk production and quality. It is considered one of the most significant causes of economic loss in the dairy industry (Pyo ¨ra ¨la ¨ and Taponen, 2009). However, during recent years, Coagulase-negative staphylococci (CNS) have become the most common bovine mastitis isolates in many countries and are regarded as emerging mastitis pathogens (Pyo ¨ ra ¨la ¨ and Taponen, 2009; Feßler et al., 2010). Antimicrobial agents are widely used in the treatment of udder infections and the efficacy of this treatment could be compromised by staphylococci that produce biofilm in the udder. The widespread use of antibiotics on dairy farms Veterinary Microbiology 155 (2012) 362–368 A R T I C L E I N F O Article history: Received 8 April 2011 Received in revised form 1 September 2011 Accepted 5 September 2011 Keywords: Coagulase-negative staphylococci Bovine mastitis Antibiotic-resistant bacteria Marine sponges Antibacterial activity A B S T R A C T Bovine mastitis remains worldwide a major challenge for the dairy industry despite the widespread implementation of control strategies. The increasing number of coagulase- negative staphylococci (CNS) causing mastitis and of bacteria resistant to conventional antibiotics has become a serious problem in recent years. Marine sponges are a rich source of bioactive compounds, and many species can be useful for the development of new antimicrobial drugs. In the present study, 49 CNS strains were isolated from bovine mastitis cases from 21 different dairy herds kept at farms in Southeast Brazil. Strains were analyzed for antimicrobial susceptibility and mecA gene detection. Fifty-nine percent of the CNS strains were resistant to at least one of the drugs tested and 12.2% were classified as multiresistant. Three strains carried the mecA gene, confering resistance to the beta- lactamic antibiotics. In addition, the CNS strains were submitted to in vitro screening for antimicrobial activities of extracts from marine sponges. Extracts from the sponge species Cinachyrella sp., Haliclona sp. and Petromica citrina showed antibacterial activity against 61% of the CNS strains, including strains resistant to conventional antibiotics. Extracts from P. citrina showed the largest spectrum of inhibitory activity. The aqueous extract inhibited 51% of the CNS strains and presented a bactericidal effect over susceptible and multiresistant-bacteria at a minimal inhibitory concentration of 1.024 mg/ml. This study shows the potential of marine sponges as new sources of antibiotics and disinfectants for the control of CNS involved in bovine mastitis. ß 2011 Elsevier B.V. All rights reserved. * Corresponding author at: Instituto de Microbiologia Paulo de Go ´ es, CCS, Bloco I, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, 373, Cidade Universita ´ ria, 21941-590 Rio de Janeiro, Brazil. Tel.: +55 21 2560 8344/133; fax: +55 21 2560 8028. E-mail address: marinella@micro.ufrj.br (M.S. Laport). Contents lists available at SciVerse ScienceDirect Veterinary Microbiology jou r nal h o mep ag e: w ww .els evier .co m/lo c ate/vetm ic 0378-1135/$ – see front matter ß 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.vetmic.2011.09.004