Class 1 integrons in clinical and swine industry isolates of Salmonella Typhimurium from Colombia, dating 1997 to 2017.

Background. Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) has been linked to outbreaks of foodborne gastroenteritis disease, and the emergence of antimicrobial-resistant clones. In Colombia, laboratory surveillance of Salmonella spp. between 1997-2018 revealed that S. Typhimurium was the most ubiquitous serovar (27.6 % of all Salmonella isolates), with increasing levels of resistance to several families of antibiotics.Hypothesis. Resistant isolates of S. Typhimurium recovered from human clinical, food and swine samples carry class 1 integrons that are linked to antimicrobial resistance genes.Aim. Identify class 1 integrons, and investigate their association with other mobile genetic elements, and their relationship to the antimicrobial resistance of Colombian S. Typhimurium isolates.Methods. In this study, 442 isolates of S. Typhimurium were analysed, of which 237 were obtained from blood culture, 151 from other clinical sources, 4 from non-clinical sources and 50 from swine samples. Class 1 integrons and plasmid incompatibility groups were analysed by PCR and whole-genome sequencing (WGS), and regions flanking integrons were identified by WGS. The phylogenetic relationship was established by multilocus sequence typing (MLST) and single-nucleotide polymorphism (SNP) distances for 30 clinical isolates.Results . Overall, 39 % (153/392) of the human clinical isolates and 22 % (11/50) of the swine S. Typhimurium isolates carried complete class 1 integrons. Twelve types of gene cassette arrays were identified, including dfr7-aac-bla OXA-2 (Int1-Col1), which was the most common one in human clinical isolates (75.2 %, 115/153). Human clinical and swine isolates that carried class 1 integrons were resistant to up to five and up to three antimicrobial families, respectively. The Int1-Col1 integron was most prevalent in stool isolates and was associated with Tn21. The most common plasmid incompatibility group was IncA/C.Conclusions. The widespread presence of the IntI1-Col1 integron in Colombia since 1997 was striking. A possible relationship between integrons, source and mobile elements that favour the spread of antimicrobial resistance determinants in Colombian S. Typhimurium was identified.

Management of swine mortalities through the use of a mixed composting-accelerating bio-inoculant.

A composting-accelerating bio-inoculant (Bacillus subtilis, Talaromyces sayulitensis (HC1), Steinernema sp., and Heterorhabditis sp.) was evaluated in a composting process made up of a different mix of wood chips, pig manure, urine, and swine mortality (raw material RM). Three different treatments (T1, T2, and T3) were assessed, and physicochemical, microbiological, and entomological evaluations were carried out at 0 and 45 days of the composting process. The highest organic nitrogen (1.34 %) concentration was detected in swine mortality, whereas the highest total oxidizable organic carbon (39.1 %) concentration was observed in wood chips. Salmonella spp., was not identified in any of the raw materials. Clostridium spp., count was 5.5, 2.0, and 1.0 Log10 unit, for pig manure, wood chips, and swine mortality, respectively. Pig manure, swine mortality, and wood chip total coliform count was 6.21, 5.32, and 1 Log10 unit, respectively. Helminth eggs were not detected in any of the RM and Cryptosporidium spp., oocysts were occasionally found in pig manure and wood chips. Several types of flies were identified, Musca domestica, Muscina stabulans, Stomoxys calcitrans, Fannia canicularis, Sarcophaga sp., and Calliphora sp. Treatment 3 (45.11 % swine mortality, 33.33 % wood chips, and 21.55 %, urine and bio-inoculant) had the greatest total oxidizable organic carbon availability, the highest carbon/nitrogen (C/N) ratio (20.67, p < 0.05), and the lowest dipterous larvae count. Moreover, Salmonella sp., was not observed and had only low Clostridium spp., and fecal coliform count. The bio-inoculant's effect on C/N ratio, cation exchange capacity, and electrical conductivity were beneficial, and resulted in production of a fertilizer complying with EPA 600/1-87-014, EPA 40 CFR Part 258, and NTC5167/11 norms. According to the characterization protocols used in this study the compost was apparently free from bacterial and parasitic pathogens and minimal dipteran counts. Last, maturation time was 15 days shorter compared with control (C4).

Salmonella spp. prevalence, antimicrobial resistance and risk factor determination in Colombian swine farms / Salmonella spp. prevalência, resistência antimicrobiana e determinação de fatores de risco em granjas suínas colombianas

To determine Salmonella spp. prevalence/seroprevalence, antimicrobial resistance patterns and risk factor identification associated with its presence in Colombian swine farms. 504 samples (Faeces, swabs and environment samples) were obtained from 21 farms distributed in four geographical regions in Colombia. Salmonella spp. microbiological and molecular detection were determined by two Salmonella spp. MDS3M™ and MALDI-TOF MS assays, respectively. In addition, for serological evaluation 231 serum samples were analyzed employing ELISA Salmonella Pigtype®-Salmonella Ab (QUIAGEN®). Additionally, 41 isolates were tested for antimicrobial susceptibility using broth microdilution technique (Panel B1016-180 Beckman Coulter NC72®) and verified with WHONET 2016 software. Risk factors were assessed from a survey and analyzed for statistical significance by U Mann-Whitney test. An 8.9% prevalence (n=45) and 38.1% (n=88) seroprevalence were determined. All isolates presented 100% antimicrobial susceptibility against amikacin. However, resistance against penicillin, tetracycline, cefuroxime and trimethoprim/sulfamethoxazole was present in more than 50% of evaluated strains. Risk factors associated with Salmonella spp. presence were surface water use, rough-surfaced on floors, presence of hoppers as feeders and worker's boots. Bacteria were present in animals and environmental samples from evaluated farms. Animal contact and/or exposure with the microorganism were also evident in obtained serological response. Bacteria presence depended on management practices and infrastructure, likewise antibiotic use, supplemented in the diet may have induced an increase in Salmonella spp. antimicrobial resistance.(AU)

Para determinar Salmonellaspp. prevalência/soroprevalência, padrões de resistência antimicrobiana e identificação de fatores de risco associados à sua presença em granjas suínas colombianas. Foram obtidas 504 amostras (fezes, zaragatoas e amostras do ambiente) de 21 fazendas distribuídas em quatro regiões geográficas da Colômbia. Salmonella spp., a detecção microbiológica e molecular foi determinada por 2 Salmonella spp. Ensaios MDS3M™ e MALDI-TOF MS, respectivamente. Além disso, para avaliação sorológica, foram analisadas 231 amostras de soro empregando ELISA Salmonella Pigtype® - Salmonella Ab (QUIAGEN®). Além disso, 41 isolados foram testados quanto à suscetibilidade antimicrobiana usando a técnica de microdiluição em caldo (Painel B1016-180 Beckman Coulter NC72®) e verificados com o software WHONET 2016. Os fatores de risco foram avaliados em uma pesquisa e analisados quanto à significância estatística pelo teste U Mann-Whitney. Foram determinadas prevalências de 8,9% (n=45) e 38,1% (n=88). Todos os isolados apresentaram 100% de suscetibilidade antimicrobiana à amicacina. No entanto, resistência à penicilina, tetraciclina, cefuroxima e trimetoprim/sulfametoxazol estava presente em mais de 50% das cepas avaliadas. Fatores de risco associados à Salmonella spp., presença de uso de água de superfície, superfície áspera no chão, presença de tremonhas como alimentadores e botas de trabalho. Bactérias estavam presentes em animais e amostras ambientais de fazendas avaliadas. O contato animal e/ou a exposição ao microrganismo também foram evidentes na resposta sorológica obtida. A presença de bactérias dependia de práticas de manejo e infraestrutura, assim como o uso de antibióticos suplementados na dieta pode ter induzido um aumento de Salmonella spp. resistência antimicrobiana.(AU)

Prevalence of Salmonella spp., in mesenteric pig's ganglia at Colombian benefit plants / Prevalencia de Salmonella spp., en ganglios mesentéricos de porcinos en plantas de beneficio Colombianas

ABSTRACT Objective. To determine the prevalence of Salmonella spp., in pigs mesenteric ganglion, from different regions of Colombia. Materials and Methods. A stratified sampling by proportional fixation was carried out at benefit plants of each of the 13 participating departments, whose pork production volume is representative at national level. Sampling was performed during five months, for a total of 457 samples analyzed. Salmonella spp., identification was performed by the MDS Molecular System, later isolates were confirmed in Maldi-TOF MS. Antimicrobial susceptibility of the isolates was determined using the B1016-180 panel and statistical analysis was performed in Whonet 2016, some of the multi-resistant isolates were them serotyped by Kauffman-White method. Results. National prevalence was 28.2%, with the presence of S. Typhimurium, S. Agama, S. London, S. Agona, S. Haifa and S. 1,4,12: i: -. Resistance to antibiotics frequently used in human (23.6% Trimethoprim/Sulfamethoxazole, 2.7% Cefotaxime (CTX), 11.8% Ampicillin (AMP) and 1.8% Ciprofloxacin) was found. Conclusion. The prevalence of Salmonella in mesenteric ganglia was 28.2%, being the Huila region the one with the highest prevalence, recovering atypical serotypes such as S. London and S. Haifa.

RESUMEN Objetivo. Determinar la prevalencia de Salmonella spp., en ganglios mesentéricos de porcinos, provenientes de diferentes regiones de Colombia. Materiales y Métodos. Se realizó un muestreo estratificado por fijación proporcional en plantas de beneficio, de cada uno de los 13 departamentos participantes, cuyo volumen de producción de carne de cerdo es representativo a nivel nacional. El muestreo se realizó durante cinco meses, para un total de 457 muestras analizadas. La identificación de Salmonella spp., se realizó mediante el Sistema Molecular MDS, luego los aislamientos fueron confirmados por Maldi-TOF MS. Se determinó la susceptibilidad antimicrobiana de los aislamientos usando el panel B1016-180 y el análisis estadístico se realizó en Whonet 2016, posteriormente algunos de los aisalmientos multi-resistentes fueron serotipificados por el método de Kauffman-White. Resultados. La prevalencia nacional fue 28.2%, con presencia de los serotipos S. Typhimurium, S. Agama, S. London, S. Agona, S. Haifa y S. 1,4,12: i : --. Se encontró resistencia a antibióticos de uso frecuente en humanos (23.6% Trimetoprim/Sulfametoxazol, 2.7% Cefotaxime (CTX), 11.8% Ampicilina (AMP) y 1.8% Ciprofloxacina). Conclusión. La prevalencia de Salmonella en ganglios mesénticos fue del 28.2%, siendo la región del Huila la que más aportó, se recuperaron serotipos atípicos como S. London y S. Haifa.