Isolates, Antimicrobial Susceptibility Profiles and Multidrug Resistance of Bacteria Cultured from Pig Submissions in New Zealand

Abstract

Data on the scope of bacterial pathogens present and the frequency of antimicrobial resistance (AMR) in New Zealand’s pigs are limited. This study describes bacterial isolates, antimicrobial susceptibility data, and multidrug resistance (MDR; resistance to ≥3 antimicrobial classes) from New Zealand pig submissions. Porcine test data from June 2003 to February 2016 were obtained from commercial veterinary pathology laboratory records. In total, 470/477 unique submissions resulted in bacterial growth, yielding 779 isolates. Sample type was recorded for 360/477 (75.5%); lung (79/360; 21.9%), faecal (61/360; 16.9%) and intestinal (45/360; 12.5%) were most common. The most common isolates were Escherichia coli (186/779, 23.9%), Actinobacillus pleuropneumoniae (43/779; 5.5%), Streptococcus suis (43/779; 5.5%), unidentified Campylobacter spp. (38/779; 4.9%), alpha haemolytic Streptococci (32/779; 4.1%), coagulase negative Staphylococcus spp. (26/779; 3.3%), and Pasteurella multocida (25/779; 3.2%). Susceptibility results were available for 141/779 (18.1%) isolates from 62/470 (13.2%) submissions. Most were susceptible to trimethoprim-sulphonamide (75/81; 92.6%), but fewer were susceptible to penicillin (37/77; 48.1%), tilmicosin (18/43; 41.9%), or tetracyclines (41/114; 36.0%). No susceptibility data were available for Salmonella spp., Campylobacter spp., or Yersinia spp. isolates. MDR was present in 60/141 (42.6%) isolates. More data on sample submission drivers, antimicrobial drug use, and susceptibilities of important porcine bacterial isolates are required to inform guidelines for prudent antimicrobial use, to reduce their prevalence, human transmission, and to minimise AMR and MDR.

Reducing the Risk of Transmission of Critical Antimicrobial Resistance Determinants From Contaminated Pork Products to Humans in South-East Asia

“…In Russia, relatively high levels of MDR Escherichia coli that are resistant to critically important antimicrobials such as colistin, cefotaxime, and ciprofloxacin have been recorded (Makarov et al, 2020). A study in New Zealand also found that the widespread use of oral antimicrobials within pig production was a significant risk factor for development of AMR and MDR E. coli (Riley et al, 2020). The rate of antibiotic resistance differs considerably from country to country, depending upon the amount of usage.…”

Resistance of Streptococcus suis Isolates from the Czech Republic during 2018–2022

“…Surprisingly, a high level of resistance to trimethoprim/sulfamethoxazole was reported in Denmark, because trimethoprim/sulfamethoxazole was presented as effective, with sensitivity to more than 90% of the isolates tested in other studies [ 33 ]. In the results of AMR monitoring in Sweden, China, and New Zealand published this year, a high percentage of S. suis isolates especially resistant to tetracycline (over 90%) was presented, as was a very good sensitivity of S. suis to beta-lactams and fluoroquinolones [ 1 , 34 , 35 ].…”

How Streptococcus suis escapes antibiotic treatments

“…However, whereas, for example, Japan, Taiwan, and Hong Kong have similar restrictions, most Asian countries still use antimicrobials for this purpose with exceptions only for some specific antibiotics [ 40 ]. Few reports from Oceania revealed overall low resistance rates for β-lactams, amphenicols, fluoroquinolones, and sulfonamides, moderate rates for macrolides, and the highest rates for tetracyclines (almost 100%), with some differences between reports [ 41 , 42 ]. In general, for most antibiotics, AMR rates were considerably lower in Oceania than in Asia.…”