Glaesserella parasuis is an important bacterial pathogen and the etiological agent of Glässer’s disease, which causes substantial economic losses on swine farms worldwide. Although large scale genome studies have been carried out in the North hemisphere, few genomes from South America are available limiting our knowledge of the full genetic diversity of this bacteria. In this study, seventeen clinical G. parasuis isolates from diseased swine in Peru where whole genome sequenced and compared with publicly available genomes. We identified seven distinct sequence types and five serotypes being more prevalent: the emergent ST454 and novel ST726 and serotypes 7 and 12. Although most isolates did not carried any antimicrobial resistance gene (ARG) we identified a large cassette of ∼50 kb carrying nine different ARGs (aac(3)-IV, aph(3′)-Ia, aph(3′)-Ib, sul2, bla_ROB–1tetB, lnuH, estT and floR) including six tandem repeats of estT and floR genes. We also identified two coexisting small plasmids harboring tetH, estT and bla_ROB–1 in two isolates. Most of the isolates (88.2%, 15/17) harbored at least one group 1 vtaA virulence gene. The G. parasuis diversity was segregated in two clades (C1 and C2) by phylogenetic and gene content analysis. We identified several genes overrepresented in both clades, however three metabolic operons (glnHMPQ, hisGDCBHAFI, thiDEM) were almost exclusive of C2 strains suggesting that C1 strains are auxotrophs for histidine and thiamine important nutrient for bacterial survival which may impact in the adaptation of these strains to the host niche. Our results suggest a high diversity of G. parasuis strains circulating in Peru, the presence of mobile elements carrying multiple ARGs underscores the need for continuous surveillance of this pathogen within the Peruvian swine industry to identify potential vaccine candidates and formulate better control programs.

The misuse of antibiotics is accelerating antimicrobial resistance (AMR) in Escherichia coli isolated from farm animals. The genomes of ten multidrug-resistant (MDR) E. coli isolates from pigs were analyzed to determine their sequence types, serotypes, virulence, and AMR genes (ARGs). Additionally, the relationship was evaluated adding all the available genomes of Peruvian E. coli from humans using the cgMLST + HierCC scheme. Two aEPEC O186:H11-ST29 were identified, of which H11 and ST29 are reported in aEPEC isolates from different sources. An isolate ETEC-O149:H10-ST100 was identified, considered a high-risk clone that is frequently reported in different countries as a cause of diarrhea in piglets. One ExPEC O101:H11-ST167 was identified, for which ST167 is an international high-risk clone related to urinary infections in humans. We identified many ARGs, including extended-spectrum β-lactamase genes, and one ETEC harboring the mcr-1 gene. CgMLST + HierCC analysis differentiated three clusters, and in two, the human isolates were grouped with those of swine in the same cluster. We observed that Peruvian swine MDR E. coli cluster with Peruvian E. coli isolates from healthy humans and from clinical cases, which is of great public health concern and evidence that AMR surveillance should be strengthened based on the One Health approach.

El objetivo del presente estudio fue identificar molecular y serológicamente Salmonella spp presentes en aislados de huevos, canales y vísceras aviares. Se evaluaron 46 aislados de origen aviar identificados como Salmonella spp mediante cultivos y pruebas bioquímicas en el periodo 2012-2017, procedentes de varios distritos de la ciudad de Lima. Estos aislados son conservados en el cepario de Laboratorio de Bacteriología de la Universidad Nacional Mayor de San Marcos. Se reactivaron las cepas, y se reconfirmaron las colonias sospechosas a Salmonella spp mediante el cultivo en medios selectivos. Posteriormente se realizó el PCR a las muestras sospechosas como método de diagnóstico genético de Salmonella. Se detectó el gen de invasividad invA, gen involucrado con la virulencia de Salmonella. Se realizó la serotipificación con antisueros polivalentes y monovalentes para serogrupo y serovar en el Laboratorio de Enteropatógenos del Instituto Nacional de Salud (INS), y finalmente se determinaron las serovariedades de acuerdo con el esquema propuesto por Kauffmann-White. Las 46 cepas evidenciaron bandas de peso molecular correspondientes al gen invA (244 pb). Todas las cepas fueron identificadas mediante serotipificación, obteniendo: S. Infantis (34.8%), S. Pullorum (34.8%), S. Gallinarum (15.2%), S. Enteritidis (8.7%) y S. Typhimurium (6.5%). Los resultados revelan la predominancia de los serovares circulantes en muestras aviares, así como su implicancia en la salud pública.

Urinary tract infections (UTIs) are common in dogs and are most frequently caused by Enterobacterales such as Escherichia coli and Klebsiella pneumoniae. The involvement of uncommon Enterobacterales with the capacity to acquire antimicrobial resistance is increasingly recognized within a One Health framework. A 3-year-old intact female mixed-breed dog presented with hematuria, lethargy and anorexia. Urinalysis and bacterial culture confirmed a urinary tract infection. The isolate was initially misidentified as Klebsiella pneumoniae by routine biochemical methods, but whole genome sequencing enabled its definitive identification as Pluralibacter gergoviae, a species previously reported mainly as an environmental and industrial contaminant and as an opportunistic human pathogen. Antimicrobial susceptibility testing showed susceptibility to all tested agents except penicillin. Whole genome sequencing revealed no acquired antimicrobial resistance genes, and phylogenomic analysis clustered the canine isolate with human and environmental P. gergoviae strains from different geographic regions. This genome-confirmed canine infection expands the known host range of P. gergoviae and highlights the role of molecular diagnostics in detecting atypical uropathogens. The phylogenomic relatedness to human and environmental strains underscores the importance of One Health-oriented genomic surveillance of opportunistic Enterobacterales across human and animal settings.

El patotipo Escherichia coli productora de toxina Shiga tipo 2e (gen stx2e) y la expresión de la fimbria F18 (gen fedA), son los principales factores de virulencia de la enfermedad del edema en cerdos. El objetivo del estudio fue detectar los genes stx2e y fedA en aislados de E. coli provenientes de hisopados rectales de cerdos de 0-50 días de edad con diarrea de granjas porcinas de Lima, Perú. De las 119 muestras analizadas mediante PCR convencional, seis muestras (5.04%) fueron positivas para el gen stx2e, y tres de ellas (2.52%) portaban, además, el gen fedA.

El estudio tuvo como objetivo la detección de los genes de resistencia a los antibióticos en aislados de Escherichia coli obtenidos de cerdos con cuadros diarreicos granjas tecnificadas de Lima Metropolitana desde 2017 hasta 2020. Se evaluaron 119 aislados de E. coli. Los aislados fueron reactivados para extraer el ADN y detectar los genes de resistencia a los principales antibióticos y de mayor importancia en la industria porcina, tales como las tetraciclinas (tetA, tetB y tetC), sulfonamidas (sul1, sul2 y sul3), estreptomicina-espectinomicina (strA/strB, aadA) y apramicina (aac(3)IV) mediante la Reacción en Cadena de Polimerasa (PCR) convencional. El 98.3% (117/119) de los aislados fueron positivos a por lo menos un gen de resistencia antimicrobiana, especialmente al grupo de las tetraciclinas (88.2%). De los 10 genes de resistencia antimicrobiana considerados, el gen tetA tuvo la frecuencia más alta (68%; 81/119), seguido del gen sul3 (64.7%; 77/119). El elevado porcentaje de genes de resistencia antimicrobiana indica una realidad a la problemática de la resistencia bacteriana contra los antimicrobianos en la zona del estudio, de allí la importancia de la vigilancia y el correcto uso de los antibióticos.