Aeromonas hydrophila isolates from clinical cases (n=43) were tested against 8 antimicrobial agents and typed by outer membrane protein (OMP) pattern by using sodium dodecyl sulfate gel electrophoresis. All isolates were resistant to ampicillin (MICs, 16 mg mL-1) and sulfamonomethoxine (MICs, 64 mg mL-1), but susceptible to norfloxacin (MICs, 0.5 mg mL-1). There was a high incidence of resistance to erythromycin (90.70%) and tylosin (93.02%), while a low incidences of resistance to ciprofloxacin (2.33%), enrofloxacin (2.33%) and florfenicol (4.65%). Six different outer membrane protein patterns were found among 34 isolates by analyzing proteins in the range of 22 to 50 kDa, other than 9 isolates with their respective profiles. The strains with the similar OMP profiles had similar resistances. Compared with the other strains from the same OMP patterns, NB-1, A.Pun and MR-1 had lacked the proteins in the range of 30 to 45 kDa and their resistance to florfenicol substantially increased. It is speculated that the outer membrane protein changes might correlate with decreased susceptibility to florfenicol in the three strains. Some strains which showed completely identical OMP types had a little difference in their resistance to fluoroquinolones, indicating that there might be other factors that were involved in the antimicrobial resistance of A. hydrophila.

Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) is a zoonotic pathogen with worldwide distribution. Lackingsuitable vaccine and virulent maker is still bottleneck to control this infection. An immunoproteomic approach has beenused to screen the membrane-associated and cell wall-associated proteins of S. zooepidemicus isolate in China CY todiscover vaccine candidate antigens and therapeutic agents. Finally, 11 membrane-associated proteins, and 13 cell wallassociatedproteins were successfully identified. BLAST (www.sanger.ac.uk) results also indicated that nucleotidesequences of majority identified proteins shared high homology (>60%) with S. zooepidemicus, except for AC1-3, AC5,AC8, and AC13. Moreover, genes for 7 of the identified proteins were detected from CY; compared with ST171, 3 of them(AM1, AM8 and AC11) were only found in virulent strains (CY). All of the proteins identified in this study remain not tobe reported in S. zooepidemicus. Some of the proteins serve a vital role in the immune system and reproduction of hostspecies according to available data, while the functions of the rest were seldom researched.