Case Report
Two and half year-old indigenous male bovine calf was brought to
Veterinary Teaching Hospital, Bangladesh Agricultural University,
Mymensingh having body weight 158 kg with the complaint of wound. Visual
examination revealed the case of myiasis leading to wound. Dressing was
performed, swab sample from wound before dressing was collected using
sterile cotton bud both from outer and inner part of wound and
transferred to nutrient broth for molecular study (Figure 1). The
collected broth samples were incubation at 37ºC for 2 hours for
enrichment and inoculated into selective media i.e. Mannitol salt agar
(MSA) and MacConkey agar (MAC) and incubated at 37º C for overnight.
Next day the growth of bacteria was observed and pure culture of each
bacteria were obtained by repeated culture of single colony. The pure
cultures of isolated bacteria were subjected to Gram´s staining for
observation of bacterial morphology, arrangement and staining
characteristics under light microscope at 10x magnification, as per the
method described by Jaman et al. [9] Bacteria from pure culture
subjected to DNA extraction by boiling method, as per described by
Khalid et al. [10] and PCR was done using S. aureus specificnuc gene and MRSA specific mec A gene primers, with an
expected protocol size 279 bp and 533 bp respectively. Forward and
Reverse primers used to detect nuc gene and mec A gene were
mentioned in Table 1.
On the basis of cultural characteristics and staining propertiesStaphylococcus aureus was identified from outer part of
wound as on Mannitol Salt Agar (MSA), Staphylococcus aureus produce golden yellow colony and on Gram´s staining it
shows Gram positive, smooth, convex, grape-like clusters (Figure 2 and
Figure 3). On the basis of PCR, it was further confirmed that the
isolated bacteria are Staphylococcus aureus and
methicillin resistant staphylococcus aureus by nuc gene
and mec A gene respectively. (Figure 4 and Figure 5)