RESUMO
The rapid emergence of antimicrobial resistance (AMR) in Campylobacter has reinforced its status as a foodborne pathogen of significant public health concern. Resistant Campylobacter is typically transferred to humans via the consumption of contaminated animal products, particularly poultry. The genes associated with antimicrobial resistance in Campylobacter spp. are poorly understood. To address this knowledge gap, we conducted a prevalence survey of AMR Campylobacter across 84 chicken farms in two districts of Bangladesh. Pooled cloacal swabs were collected from chickens and underwent bacteriological testing for Campylobacter spp. with PCR confirmation. Antimicrobial susceptibility was tested against 14 antibiotics by disk diffusion method, and 12 resistance genes were screened in Campylobacter-positive isolates using multiplex PCR. A total of 34 (40.5%) farms were Campylobacter-positive of which 73.5% of isolates were resistant to at least 10 antibiotics. The antimicrobial susceptibility results indicate a high level of resistance against streptomycin (97.1%), clindamycin (97.1%), ampicillin (94.1%), tetracycline (94.1%), erythromycin (91.2%), ciprofloxacin (88.2%), nalidixic acid (85.3%), and imipenem (82.4%), and comparatively a low frequency of resistance to chloramphenicol (47.1%), ceftazidime (44.1%), and colistin (35.3%). Multidrug-resistant (MDR) and extensively drug-resistant Campylobacter were identified in 97.1%, and 50% of isolates, respectively. Ten resistance genes were identified including blaTEM (in 97.1% of isolates), strA-strB (85.9%), tetA (70.6%), tetB (32.4%), qnrS (23.5%), blaCTX-M-1 (20.6%), qnrB (20.6%), blaSHV (8.8%), aadB (5.9%), and qnrA (2.9%). Our findings demonstrate that resistance to ampicillin, tetracycline, and ceftazidime in Campylobacter isolates was significantly (p ≤ 0.05) associated with the presence of blaTEM, tetA, and blaSHV genes, respectively. The high rates of AMR in Campylobacter isolates from our study are not surprising given the liberal use of antimicrobials and incomplete biosecurity provisions on farms. Of particular concern are resistance rates to those classes of antibiotics that should be reserved for human use (azithromycin, ciprofloxacin, and colistin). AMR was more prevalent in chicken farms that used multiple antibiotics, engaged in prophylactic treatment of the birds, and improperly disposed of antibiotic packages. The high prevalence of MDR in chicken-derived Campylobacter isolates from the different regions of our study reinforces the need for more prudent use of antimicrobial compounds in Bangladeshi chicken farms.
RESUMO
Rabies is a contagious viral disease that can be easily transmitted by the saliva and brain/nervous system tissues of the infected animals, causing severe and fatal encephalitis in both animals and humans. Vaccination campaigns are crucial to combat and prevent rabies's spread in dogs and humans. The Modified Fuenzalida & Palicios vaccines have been widely used since the 70s and have proven effective in producing a solid serological response. Since 2008, the Brazilian Ministry of Health has introduced a Cell Culture Rabies Vaccine (CCRV) for all dog mass vaccination campaigns in Brazil. However, to date, there is limited evidence on the immunologic response of dogs to this type of vaccine in field conditions. The present study evaluated the serological response in dogs vaccinated with CCRV from blood samples of 724 dogs using the Simplified Fluorescence Inhibition Microtest - SFIMT. Dogs with a titer equal to 0.5 IU/mL or above were considered seropositive. The results revealed that 59.12% (428/724) of all dogs tested and 48.49% (32/66) of primo-vaccinated animals were seropositive. The percentage of seronegative animals was higher than seropositive for animals that received a single dose during their life (p < 0.05). The opposite was observed in animals with five or more doses. The results of this study demonstrated that the CCRV vaccines elicit a satisfactory immunological response in field conditions and can constitute an essential population-level preventive strategy as part of annual canine rabies vaccination campaigns. Although its effectiveness has been studied, there is limited evidence of its immunological response in dogs under field conditions. This paper evaluates the serological response to CCRV in dogs vaccinated during mass vaccination campaigns from 2012 to 2017.