Table 2. Groups of MRSA isolates among farmers and livestock; antimicrobial susceptibility patterns of MRSA with oxacillin minimal inhibitory concentration (μg/mL).
| Group number according to ASP and MIC | Oxacillin MIC (μg/mL) | Antimicrobial susceptibility pattern | Number of strains from livestock | Number of strains from farmers | χ(df)= value and p value | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doxycycline | Penicillin | Ciprofloxacin | Clindamycin | Erythromycin, | Gentamicin | Trimethoprim-sulfamethoxazole | Pigs | Chicks | Cattle | Pig farmers | Poultry farmers | Cattle farmers | |||
| 1 | >128 | S | R | R | R | R | R | S | 4 | 2 | (1)=11.4 0.031 | ||||
| 2 | 64 | R | R | R | R | R | R | S | 8* | 2 | 4* | 1 | (1)=10.4 0.031 | ||
| 3 | 128 | S | R | S | S | R | S | S | - | 1 | - | ||||
| 4 | >128 | R | R | S | S | S | R | S | - | 1 | - | ||||
| 5 | 32 | R | R | R | R | R | R | R | 1 | - | - | ||||
| 6 | 64 | R | R | R | R | R | R | S | 2 | - | |||||
| 7 | 64 | S | R | R | R | R | R | S | 1 | ||||||
| 8 | 128 | R | R | S | S | R | S | S | 1 | ||||||
| 9 | >128 | R | R | S | S | S | S | S | 1 | ||||||
| 10 | 32 | R | R | R | R | R | R | S | 3 | ||||||
| 11 | 32 | S | R | R | R | R | R | S | 2 | 2 | 0.06 | ||||
| 12 | >128 | R | R | R | R | R | R | S | 1 | 1 | 0.06 | ||||
| 13 | 32 | S | R | R | R | S | R | S | 1 | ||||||
| 14 | 32 | R | R | R | R | S | S | S | 1 | ||||||
ASP – antimicrobial susceptibility pattern; R – resistant; S – susceptible.
All MRSA isolates were susceptible to vancomycin, teicoplanin, linezolid and fusidic acid. P value <0.05 was taken as significant.