The association between the somatic cell count and isolated microorganisms during subclinical mastitis in heifers in Jordan

Abstract

ABSTRACT:Mastitis is an important cause of early culling of dairy heifers. The aims of this study were to identify microorganisms that cause subclinical mastitis (SCM) in Holstein heifers in northern Jordan, to estimate the relative importance of various microorganisms, and to examine the correlation between the somatic cell count (SCC) and the isolated microorganisms. Composite milk samples were collected aseptically from 133 Holstein heifers between Days 5 and 14 postpartum for bacterial culture and somatic cell counts. The prevalence of subclinical mastitis in this study was 57.1%. Seventy six (76) of the 133 cows tested had SCC of > 250 000 cells/ml. Bacteria were isolated from 36 (27.1%) cows. About sixty six percent (66.7%) of these isolates were cultured from cows with subclinical mastitis. Coagulase-negative Staphylococci (CNS) were the most prevalent bacteria among isolates (50%), followed by Staphylococcus aureus (22.2%), Corynebacterium bovis and coliforms (E. coli and Klebsiella pneumoniae) (5.6% each), and Streptococcus uberis (2.8%). Interestingly, the majority of the negativeculture samples (53.6%) had elevated SCC. All isolates except for the CNS group exhibited strongly elevated SCC (> 1 × 10 6 cells/ml). However, the coagulase-negative Staphylococci did not have a distinct pattern with respect to SCCs. There was a strong correlation (P ≤ 0.05, correlation coefficient 0.213) between the results of bacterial culture (culture-positive vs. culture-negative) and SCC class but not between SCC class and the type of isolated bacteria. It is concluded that subclinical mastitis appears to be a significant health issue for dairy heifers in Jordan.

Subclinical mastitis in dairy cows: somatic cell counts and associated bacteria in Mymensingh, Bangladesh

“…Most frequently isolated bacteria was staphylococcus aureus (18.33%) which suggests that the prevention of spread of contagious bacteria during milking was not effective. Similar to this, Staphylococcus aureus was the most frequently isolated pathogen in Sweeden (19%), Jordan (22.2%), and Brazil (30.8%) (Persson et al, 2011;Malek dos Reis et al, 2011;Alekish, 2015). Besides other minor pathogens, Staphylococcus aureus was still the most prevalent pathogen in clinically healthy animals and both environmental and contagious forms of mastitis may be caused by Staphylococcus aureus (Rall et al, 2013;Barkema et al, 2009).…”

The effect of dry cow therapy using systemic tylosin in combination with common intramammary medications on mastitis rate, cull rate, somatic cell count, and milk production in dairy cows affected with subclinical mastitis

“…Mastitis remains one of the most common and economically devastating diseases affecting the dairy cow industry in Jordan [ 11 - 14 ] as well as elsewhere in the world [ 15 - 19 ]. In the herd under study here, the prevalence of subclinical mastitis was 39.3%.…”

“…In the herd under study here, the prevalence of subclinical mastitis was 39.3%. The prevalence of subclinical mastitis in Jordan has been reported to reach up to 94% in some studies [ 11 - 14 ]. This great variation in the prevalence of subclinical mastitis has been suggested to be due to differences in the methods of diagnosis (CMT vs. SCC), geographical differences, and differences in milking and environmental management between herds [ 11 , 12 ].…”

“…Samples were kept on ice during transportation to the laboratory. Somatic cell count (SCC) was performed manually within 2 h after sample collection [ 11 ]. Briefly, a 0.01 ml of thoroughly mixed milk from each sample was spread on a 1 cm 2 area on a glass slide.…”

In vitro antibacterial effects of zinc oxide nanoparticles on multiple drug-resistant strains of Staphylococcus aureus and Escherichia coli: An alternative approach for antibacterial therapy of mastitis in sheep

“…Approximately 0.01 ml of milk from each sample was cultured on 5% sheep Blood Agar Plates and MacConkey Agar Plates (Oxoid, UK) [ 19 ]. The agar plates were initially incubated at 37°C for 18-24 h. If no growth appeared after 24 h, incubation was extended for another 24 h before final judgment was taken.…”