关键词: 深圳；猪链球菌；屠宰场；血清型；药敏试验

Abstract: Streptococcus suis is an important zoonotic pathogen，with most healthy pigs carry one or multiple serotypes of S. suis，which constitutes a potential health threat to workers in the pig slaughtering industry. This study investigated the serotypes distribution and antimicrobial resistance profiles of S. suis isolates from slaughterhouses， aiming to provide references for improving public health safety. Tonsil samples were collected from healthy pigs in three slaughterhouses around Shenzhen. S. suis was isolated and identified，followed by serotyping via PCR. Antimicrobial susceptibility testing was performed using the disk diffusion method to determine the resistance profiles of the isolates. A total of 50 tonsil samples were collected，of with 35 testing positive for S. suis，yielding an overall positivity rate of 70.00%. Slaughterhouse A had a positivity rate of 73.33%（11/15），with three serotype 2 strains isolated，and serotypes 1 and 24 being predominant. Slaughterhouse B had a positivity rate of 70.00%（14/20），with two serotype 2 strains isolated，and serotype 16 being predominant. Slaughterhouse C had a positivity rate of 66.67% （10/15），with no serotype 2 strains isolated，and serotype 20 being predominant. Multidrug resistance was observed in all isolates. The resistance rates were as follows：doxycycline，97.14%（34/35）；azithromycin，91.43%（32/35）； gentamicin，60.00%（21/35）；kanamycin，54.29%（19/35）；florfenicol，34.29%（12/35）；amoxicillin，28.57%（10/ 35）；cefotaxime，11.43%（4/35）；and amoxicillin-clavulanate，2.86%（1/35）. The high carriage rate of S. suis in healthy pigs in this region，combined with the predominance of zoonotic serotypes and multidrug resistance， underscores the need for continuous surveillance to inform the development of effective prevention and control strategies.

Key words: Shenzhen；Streptococcus suis；Slaughterhouse；Serotype；Antimicrobial susceptibility testing