A study was carried out to establish the prevalence
of subclinical mastitis (SCM) in smallholder dairy farms in
Ismailia, Egypt. A total of 340 milking cows and buffaloes
were sampled from 60 farms, and 50 nasal swabs were collected
from consenting farm workers. Milk samples were
subjected to California mastitis test (CMT) and the positive
samples were examined by bacterial culture and PCR to
identify etiological agents. Based on CMT, the prevalence of
SCM was 71.6 % in cattle and 43.5 % in buffaloes while the
prevalence was 25.2 % at cow-quarter level and 21.7 % at
buffaloes-quarter level. Bacteriological analysis showed that
the most frequently identified bacteria were Staphylococcus
(S.) aureus (38.3 %) and Streptococcus (Str.) agalactiae
(20 %). The diagnostic sensitivity of PCR compared to bacterial
culture was superior with S. aureus and Str. agalactiae
detection being 41 and 22.6 %, respectively. Furthermore,
methicillin-resistant S. aureus (MRSA) strains occurred in
52.2 and 45 % of isolates of animals and workers, respectively.
Subclinical mastitis due to S. aureus and Str. agalactiae is
endemic in smallholder dairy herds in Ismailia. The occurrence
of MRSA in animals and workers highlights a need for
wide epidemiological studies of MRSA and adopting control
strategies