RESUMEN
Wild birds are common reservoirs of Salmonella enterica. Wild birds carrying resistant S. enterica may pose a risk to public health as they can spread the resistant bacteria across large spatial scales within a short time. Here, we whole-genome sequenced 375 S. enterica strains from wild birds collected in 41 U.S. states during 1978-2019 to examine bacterial resistance to antibiotics and heavy metals. We found that Typhimurium was the dominant S. enterica serovar, accounting for 68.3% (256/375) of the bird isolates. Furthermore, the proportions of the isolates identified as multi-antimicrobial resistant (multi-AMR: resistant to at least three antimicrobial classes) or multi-heavy metal resistant (multi-HMR: resistant to at least three heavy metals) were both 1.87% (7/375). Interestingly, all the multi-resistant S. enterica (n = 12) were isolated from water birds or raptors; none of them was isolated from songbirds. Plasmid profiling demonstrated that 75% (9/12) of the multi-resistant strains carried resistance plasmids. Our study indicates that wild birds do not serve as important reservoirs of multi-resistant S. enterica strains. Nonetheless, continuous surveillance for bacterial resistance in wild birds is necessary because the multi-resistant isolates identified in this study also showed close genetic relatedness with those from humans and domestic animals.
Asunto(s)
Antiinfecciosos , Metales Pesados , Salmonelosis Animal , Salmonella enterica , Animales , Animales Salvajes/genética , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Aves , Farmacorresistencia Bacteriana Múltiple/genética , Metales Pesados/farmacología , Pruebas de Sensibilidad Microbiana , Plásmidos , Salmonelosis Animal/epidemiología , Salmonelosis Animal/microbiología , Estados UnidosRESUMEN
Salmonella enterica serovar Typhimurium is typically considered a host generalist; however, certain isolates are associated with specific hosts and show genetic features of host adaptation. Here, we sequenced 131 S. Typhimurium isolates from wild birds collected in 30 U.S. states during 1978-2019. We found that isolates from broad taxonomic host groups including passerine birds, water birds (Aequornithes), and larids (gulls and terns) represented three distinct lineages and certain S. Typhimurium CRISPR types presented in individual lineages. We also showed that lineages formed by wild bird isolates differed from most isolates originating from domestic animal sources, and that genomes from these lineages substantially improved source attribution of Typhimurium genomes to wild birds by a machine learning classifier. Furthermore, virulence gene signatures that differentiated S. Typhimurium from passerines, water birds, and larids were detected. Passerine isolates tended to lack S. Typhimurium-specific virulence plasmids. Isolates from the passerine, water bird, and larid lineages had close genetic relatedness with human clinical isolates, including those from a 2021 U.S. outbreak linked to passerine birds. These observations indicate that S. Typhimurium from wild birds in the United States are likely host-adapted, and the representative genomic data set examined in this study can improve source prediction and facilitate outbreak investigation. IMPORTANCE Within-host evolution of S. Typhimurium may lead to pathovars adapted to specific hosts. Here, we report the emergence of disparate avian S. Typhimurium lineages with distinct virulence gene signatures. The findings highlight the importance of wild birds as a reservoir for S. Typhimurium and contribute to our understanding of the genetic diversity of S. Typhimurium from wild birds. Our study indicates that S. Typhimurium may have undergone adaptive evolution within wild birds in the United States. The representative S. Typhimurium genomes from wild birds, together with the virulence gene signatures identified in these bird isolates, are valuable for S. Typhimurium source attribution and epidemiological surveillance.
Asunto(s)
Enfermedades de las Aves , Salmonelosis Animal , Salmonella enterica , Animales , Animales Salvajes , Enfermedades de las Aves/epidemiología , Salmonelosis Animal/epidemiología , Salmonella enterica/genética , Salmonella typhimurium , Serogrupo , Estados UnidosRESUMEN
Birds are highly susceptible to aspergillosis, which can manifest as a primary infection in both domestic and wild birds. Aspergillosis in wild birds causes mortalities ranging in scale from single animals to large-scale epizootic events. However, pathogenicity factors associated with aspergillosis in wild birds have not been examined. Specifically, it is unknown whether wild bird-infecting strains are host-adapted (i.e. phylogenetically related). Similarly, it is unknown whether epizootics are driven by contact with clonal strains that possess unique pathogenic or virulence properties, or by distinct and equally pathogenic strains. Here, we use a diverse collection of Aspergillus fumigatus isolates taken from aspergillosis-associated avian carcasses, representing 24 bird species from a wide geographic range, and representing individual bird mortalities as well as epizootic events. These isolates were sequenced and analyzed along with 130 phylogenetically diverse human clinical isolates to investigate the genetic diversity and phylogenetic placement of avian-associated A. fumigatus, the geographic and host distribution of avian isolates, evidence for clonal outbreaks among wild birds, and the frequency of azole resistance in avian isolates. We found that avian isolates were phylogenetically diverse, with no clear distinction from human clinical isolates, and no sign of host or geographic specificity. Avian isolates from the same epizootic events were diverse and phylogenetically distant, suggesting that avian aspergillosis is not contagious among wild birds and that outbreaks are likely driven by environmental spore loads or host comorbidities. Finally, all avian isolates were susceptible to Voriconazole and none contained the canonical azole resistance gene variants.
Asunto(s)
Aspergilosis , Aspergillus fumigatus , Animales , Antifúngicos/farmacología , Aspergilosis/epidemiología , Aspergilosis/veterinaria , Aspergillus fumigatus/genética , Azoles , Aves , Farmacorresistencia Fúngica/genética , Proteínas Fúngicas/genética , Genotipo , Especificidad del Huésped , Pruebas de Sensibilidad Microbiana , FilogeniaRESUMEN
Botulinum neurotoxin serotype E (BoNT/E) outbreaks in the Great Lakes region cause large annual avian mortality events, with an estimated 17,000 bird deaths reported in 2007 alone. During an outbreak investigation, blood collected from bird carcasses is tested for the presence of BoNT/E using the mouse lethality assay. While sensitive, this method is labor-intensive and low throughput and can take up to 7 days to complete. We developed a rapid and sensitive in vitro assay, the BoTest Matrix E assay, that combines immunoprecipitation with high-affinity endopeptidase activity detection by Förster resonance energy transfer (FRET) to rapidly quantify BoNT/E activity in avian blood with detection limits comparable to those of the mouse lethality assay. On the basis of the analysis of archived blood samples (n = 87) collected from bird carcasses during avian mortality investigations, BoTest Matrix E detected picomolar quantities of BoNT/E following a 2-h incubation and femtomolar quantities of BoNT/E following extended incubation (24 h) with 100% diagnostic specificity and 91% diagnostic sensitivity.
Asunto(s)
Enfermedades de las Aves/diagnóstico , Análisis Químico de la Sangre/métodos , Toxinas Botulínicas/sangre , Botulismo/veterinaria , Técnicas de Química Analítica/métodos , Animales , Aves , Botulismo/diagnóstico , Transferencia Resonante de Energía de Fluorescencia/métodos , Great Lakes Region , Inmunoprecipitación/métodos , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
White-nose syndrome (WNS), an emerging fungal disease of North American bats, was first diagnosed in January 2008, although mortality and photodocumentation suggest the disease might have been present earlier. Using archived samples, we describe a definitive case of WNS in little brown bats (Myotis lucifugus) from New York, US, in spring 2007.
Asunto(s)
Ascomicetos/aislamiento & purificación , Quirópteros/microbiología , Dermatomicosis/veterinaria , Animales , Dermatomicosis/epidemiología , Dermatomicosis/patología , New York/epidemiologíaRESUMEN
A newly developed polymerase chain reaction (PCR)-based method to rapidly and specifically detect Geomyces destructans on the wings of infected bats from small quantities (1-2 mg) of tissue is described in the current study (methods for culturing and isolating G. destructans from bat skin are also described). The lower limits of detection for PCR were 5 fg of purified fungal DNA or 100 conidia per 2 mg of wing tissue. By using histology as the standard, the PCR had a diagnostic specificity of 100% and a diagnostic sensitivity of 96%, whereas the diagnostic sensitivity of culture techniques was only 54%. The accuracy and fast turnaround time of PCR provides field biologists with valuable information on infection status more rapidly than traditional methods, and the small amount of tissue required for the test would allow diagnosis of white-nose syndrome in live animals.
Asunto(s)
Ascomicetos/aislamiento & purificación , Quirópteros , Dermatomicosis/veterinaria , Reacción en Cadena de la Polimerasa/veterinaria , Animales , Dermatomicosis/diagnóstico , Dermatomicosis/microbiología , Reacción en Cadena de la Polimerasa/métodos , Factores de TiempoRESUMEN
We isolated Bisgaard taxon 40 from Rhinoceros Auklets ( Cerorhinca monocerata) with pneumonia and septicemia from Washington, US, found dead in 2016. Previously isolated only from the respiratory tract of a gull (Laridae), little is known about its pathogenic potential and whether it acts as a primary or opportunistic pathogen.
Asunto(s)
Bacterias/clasificación , Bacterias/aislamiento & purificación , Infecciones Bacterianas/veterinaria , Enfermedades de las Aves/microbiología , Charadriiformes , Animales , Bacterias/genética , Infecciones Bacterianas/microbiología , Infecciones Bacterianas/mortalidad , Enfermedades de las Aves/mortalidad , Enfermedades de las Aves/patología , Femenino , Masculino , WashingtónRESUMEN
Salmonella spp. are frequently shed by wildlife including turtles, but S. enterica subsp. enterica serovar Typhimurium or lesions associated with Salmonella are rare in turtles. Between 1996 and 2016, we necropsied 127 apparently healthy pelagic olive ridley turtles (Lepidochelys olivacea) that died from drowning bycatch in fisheries and 44 live or freshly dead stranded turtles from the west coast of North and Central America and Hawaii. Seven percent (9/127) of pelagic and 47% (21/44) of stranded turtles had renal granulomas associated with S. Typhimurium. Stranded animals were 12 times more likely than pelagic animals to have Salmonella-induced nephritis suggesting that Salmonella may have been a contributing cause of stranding. S. Typhimurium was the only Salmonella serovar detected in L. olivacea, and phylogenetic analysis from whole genome sequencing showed that the isolates from L. olivacea formed a single clade distinct from other S. Typhimurium. Molecular clock analysis revealed that this novel clade may have originated as recently as a few decades ago. The phylogenetic lineage leading to this group is enriched for non-synonymous changes within the genomic area of Salmonella pathogenicity island 1 suggesting that these genes are important for host adaptation.
Asunto(s)
Adaptación Fisiológica , Interacciones Huésped-Patógeno , Enfermedades Renales/veterinaria , Salmonella typhimurium/fisiología , Tortugas/microbiología , Animales , Enfermedades Renales/microbiología , Océano Pacífico , Salmonella typhimurium/genéticaRESUMEN
We report acute fatal pasteurellosis in wild big brown bats (Eptesicus fuscus) in Wisconsin, USA. Mortality of approximately 100 bats was documented over 4 wk, with no evidence for predatory injuries. Pasteurella multocida serotype 1 was isolated from multiple internal organs from four of five bats examined postmortem.
Asunto(s)
Quirópteros/microbiología , Brotes de Enfermedades/veterinaria , Infecciones por Pasteurella/veterinaria , Pasteurella multocida/aislamiento & purificación , Animales , Femenino , Masculino , Infecciones por Pasteurella/diagnóstico , Infecciones por Pasteurella/mortalidad , Wisconsin/epidemiologíaRESUMEN
White-nose syndrome (WNS) is a condition associated with an unprecedented bat mortality event in the northeastern United States. Since the winter of 2006*2007, bat declines exceeding 75% have been observed at surveyed hibernacula. Affected bats often present with visually striking white fungal growth on their muzzles, ears, and/or wing membranes. Direct microscopy and culture analyses demonstrated that the skin of WNS-affected bats is colonized by a psychrophilic fungus that is phylogenetically related to Geomyces spp. but with a conidial morphology distinct from characterized members of this genus. This report characterizes the cutaneous fungal infection associated with WNS.