Etiology, antimicrobial susceptibility profile of Staphylococcus spp. and risk factors associated with bovine mastitis in the states of Bahia and Pernambuco

Abstract

The purpose of this paper was to study the etiology of mastitis, determine the antimicrobial susceptibility profile of Staphylococcus spp. and to identify the risk factors associated with infection in dairy cows in the states of Bahia and Pernambuco, Brazil. From the 2,064 milk samples analyzed, 2.6% were associated with cases of clinical mastitis and 28.2% with subclinical mastitis. In the microbiological culture, Staphylococcus spp. (49.1%) and Corynebacterium spp. (35.3%) were the main agents found, followed by Prototheca spp. (4.6%) and Gram negative bacilli (3.6%). In the antimicrobial susceptibility testing, all 218 Staphylococcus spp. were susceptible to rifampicin and the least effective drug was amoxicillin (32.6%). Multidrug resistance to three or more drugs was observed in 65.6% of Staphylococcus spp. The risk factors identified for mastitis were the extensive production system, not providing feed supplements, teat drying process, not disinfecting the teats before and after milking, and inadequate hygiene habits of the milking workers. The presence of multiresistant isolates in bovine milk demonstrates the importance of the choice and appropriate use of antimicrobial agents. Prophylactic and control measures, including teat antisepsis and best practices for achieving hygienic milking should be established in order to prevent new cases of the disease in herds.INDEX TERMS: Staphylococcus spp., multidrug resistance, mammary gland, risk factors.

Biofilm production and beta-lactamic resistance in Brazilian Staphylococcus aureus isolates from bovine mastitis

“…In this study, all isolates were sensitive to oxacillin and cefoxitin in the disk diffusion test, supporting the results of previous studies stating that the prevalence of oxacillin resistance in S . aureus isolates from bovine mastitis is low 38, 39. In the diffusion disk test, 15 isolates showed a sensitivity zone >29 mm, but five were resistant to penicillin.…”

“…In the edge zone test, 100% (15/15) of the sensitive isolates were positive and were reported as penicillin resistant. A previous study has reported high resistance to penicillin in coagulase-positive staphylococci isolated from bovine mastitis cases 38 . However, this antibiotic is rarely considered a treatment option for mastitis, although some producers still insist on using it due to its low cost.…”

Bactérias Da Mastite Subclínica Bovina: Suscetibilidade a Antibióticos

“…e Streptococcus spp. e sua escolha foi baseada na frequência em que eles são descritos como principais agentes causadores de mastite subclínica (RIBEIRO et al, 2008;OLIVEIRA et al, 2011;KREWER et al, 2013;ACOSTA et al, 2016;SHAHEEN;TANTARY;NABI 2016;ZIMERMANN et al, 2017).…”

Temporal profile of antimicrobial resistance exhibited by strains of Staphylococcus spp. isolated from cases of bovine mastitis for 20 years (1992-2011)

“…Among the etiological agents, Staphylococcus spp. is cited as the most prevalent micro-organism involved in subclinical mastitis (KREWER et al, 2013). Staphylococcus aureus is the most pathogenic species (CARVALHO et al, 2007) and is characterized by high invasiveness and formation of fibrous tissue at the site of infection, leading to chronic cases that are characterised by low cure rates (SANTOS & FONSECA, 2007).…”

“…The selective pressure imposed by the constant use of antimicrobials and the presence of resistance genes are the most important features in the occurrence of this phenomenon (PHILLIPS et al, 2004). Several studies with microorganisms isolated from the milk of cows with mastitis reported different patterns of susceptibility to antimicrobial agents (FREITAS et al, 2005;MEDEIROS et al, 2009;KREWER et al, 2013). Nevertheless, there is a lack of information regarding the temporal changes in the susceptibility of these pathogens to antimicrobial agents used in the treatment of this disease (LINDEMAN et al, 2013).…”