Aerococcus viridans, a less frequently isolated bacteria, is a gram-positive, catalase-negative coccus, found singly or in tetrads, with biochemical and growth characteristics of streptococci and enterococci. This mic...Aerococcus viridans, a less frequently isolated bacteria, is a gram-positive, catalase-negative coccus, found singly or in tetrads, with biochemical and growth characteristics of streptococci and enterococci. This microorganism, usually susceptible to penicillin, is often found in the environment and is infrequently associated with human/veterinary infections. We described a case of Holstein Friesian female calf, 150-day-old, affected by respiratory emergencies. Following the clinical signs, radiographic analysis and bacteriological/molecular examinations carried out on blood culture, a diagnosis of severe broncho-pulmonary disease associate with a multidrug-resistant A. viridans bacteremia was done. The present case highlights the invasive nature of a saprophytic bacterium showing a broad profile of antibiotic-resistance including β-lactams. Furthermore, this report confirms that the effectiveness of an antibiotic therapy is based primarily on a sure diagnosis including susceptibility testing.展开更多
During the survey of potential pathogens in the Tian-e-zhou National Reserve for Lipotes vexillifer in Shishou,China,isolate SS20210504 was isolated from the diseased prey fish-Pelteobagrus fulvidraco and was identifi...During the survey of potential pathogens in the Tian-e-zhou National Reserve for Lipotes vexillifer in Shishou,China,isolate SS20210504 was isolated from the diseased prey fish-Pelteobagrus fulvidraco and was identified as Aerococcus viridans through 16S rRNA gene,morphological observation,and physiological and biochemical analysis.Artificial infection trials with fish through different methods were conducted.Results indicated that the isolate of SS2021504 caused mortality in fish with the LD50 of 1.0×106.2 CFU/mL,1.0×107.9 CFU/mL and 1.0×106.8 CFU/mL with the infection method of intraperitoneal injection,co-immersion,and scratch immersion,respectively.Challenged fish exhibited hemorrhages signs similar to naturally diseased fish.Histology analysis showed that the liver and kidney were the principal target organs of isolate SS2021504 in fish,and obvious vacuolation and karyopyknosis occurred in the above organs.To evaluate the pathogenicity of isolate SS20210504 in mice,healthy mice and immunosuppressed mice were further experimentally infected with bacteria,respectively.No death was observed either in healthy mice or in immunocompromised mice.However,the immunocompromised mice inoculated with bacteria showed obvious clinical symptoms and severe damage to multiple organs.The inflammatory signaling pathways were significantly activated with upregulated levels of Myd88,TNFα,AP-1,IL-1β,IL-6,and IFN-γgene in the spleen from the immunocompromised mice after infected with isolate SS20210504.These findings imply that isolate SS20210504 has the potential risk to YFPs and residents.Continued surveillance of A.viridans and other pathogens in the TZO reserve is suggested to prevent outbreaks in prey fish,YFPs,and residents as well.展开更多
There are limited biosecurity measures directed at preventing airborne transmission of viruses in swine.The effectiveness of dust mitigation strategies such as oil sprinkling,to decrease risk of airborne virus transmi...There are limited biosecurity measures directed at preventing airborne transmission of viruses in swine.The effectiveness of dust mitigation strategies such as oil sprinkling,to decrease risk of airborne virus transmission are unknown.Metagenomics and qPCR for common fecal viruses were used to hunt for a ubiquitous virus to serve as a proxy when evaluating the efficiency of mitigation strategies against airborne viral infectious agents.Air particles were collected from swine buildings using high-volume air samplers.Extracted DNA and RNA were used to perform specific RT-qPCR and qPCR and analyzed by highthroughput sequencing.Porcine astroviruses group 2 were common(from 102 to 105 genomic copies per cubic meter of air or gc/m^(3),93%positivity)while no norovirus genogroup II was recovered from air samples.Porcine torque teno sus virus were detected by qPCR in low concentrations(from 101 to 102 gc/m^(3),47%positivity).Among the identified viral families by metagenomics analysis,Herelleviridae,Microviridae,Myoviridae,Podoviridae,and Siphoviridae were dominant.The phage vB_AviM_AVP of Aerococcus was present in all air samples and a newly designed qPCR revealed between 101 and 105 gc/m^(3) among the samples taken for the present study(97%positivity)and banked samples from5-and 15-year old studies(89%positivity).According to the present study,both the porcine astrovirus group 2 and the phage vB_AviM_AVP of Aerococcus could be proxy for airborne viruses of swine buildings.展开更多
文摘Aerococcus viridans, a less frequently isolated bacteria, is a gram-positive, catalase-negative coccus, found singly or in tetrads, with biochemical and growth characteristics of streptococci and enterococci. This microorganism, usually susceptible to penicillin, is often found in the environment and is infrequently associated with human/veterinary infections. We described a case of Holstein Friesian female calf, 150-day-old, affected by respiratory emergencies. Following the clinical signs, radiographic analysis and bacteriological/molecular examinations carried out on blood culture, a diagnosis of severe broncho-pulmonary disease associate with a multidrug-resistant A. viridans bacteremia was done. The present case highlights the invasive nature of a saprophytic bacterium showing a broad profile of antibiotic-resistance including β-lactams. Furthermore, this report confirms that the effectiveness of an antibiotic therapy is based primarily on a sure diagnosis including susceptibility testing.
文摘During the survey of potential pathogens in the Tian-e-zhou National Reserve for Lipotes vexillifer in Shishou,China,isolate SS20210504 was isolated from the diseased prey fish-Pelteobagrus fulvidraco and was identified as Aerococcus viridans through 16S rRNA gene,morphological observation,and physiological and biochemical analysis.Artificial infection trials with fish through different methods were conducted.Results indicated that the isolate of SS2021504 caused mortality in fish with the LD50 of 1.0×106.2 CFU/mL,1.0×107.9 CFU/mL and 1.0×106.8 CFU/mL with the infection method of intraperitoneal injection,co-immersion,and scratch immersion,respectively.Challenged fish exhibited hemorrhages signs similar to naturally diseased fish.Histology analysis showed that the liver and kidney were the principal target organs of isolate SS2021504 in fish,and obvious vacuolation and karyopyknosis occurred in the above organs.To evaluate the pathogenicity of isolate SS20210504 in mice,healthy mice and immunosuppressed mice were further experimentally infected with bacteria,respectively.No death was observed either in healthy mice or in immunocompromised mice.However,the immunocompromised mice inoculated with bacteria showed obvious clinical symptoms and severe damage to multiple organs.The inflammatory signaling pathways were significantly activated with upregulated levels of Myd88,TNFα,AP-1,IL-1β,IL-6,and IFN-γgene in the spleen from the immunocompromised mice after infected with isolate SS20210504.These findings imply that isolate SS20210504 has the potential risk to YFPs and residents.Continued surveillance of A.viridans and other pathogens in the TZO reserve is suggested to prevent outbreaks in prey fish,YFPs,and residents as well.
文摘There are limited biosecurity measures directed at preventing airborne transmission of viruses in swine.The effectiveness of dust mitigation strategies such as oil sprinkling,to decrease risk of airborne virus transmission are unknown.Metagenomics and qPCR for common fecal viruses were used to hunt for a ubiquitous virus to serve as a proxy when evaluating the efficiency of mitigation strategies against airborne viral infectious agents.Air particles were collected from swine buildings using high-volume air samplers.Extracted DNA and RNA were used to perform specific RT-qPCR and qPCR and analyzed by highthroughput sequencing.Porcine astroviruses group 2 were common(from 102 to 105 genomic copies per cubic meter of air or gc/m^(3),93%positivity)while no norovirus genogroup II was recovered from air samples.Porcine torque teno sus virus were detected by qPCR in low concentrations(from 101 to 102 gc/m^(3),47%positivity).Among the identified viral families by metagenomics analysis,Herelleviridae,Microviridae,Myoviridae,Podoviridae,and Siphoviridae were dominant.The phage vB_AviM_AVP of Aerococcus was present in all air samples and a newly designed qPCR revealed between 101 and 105 gc/m^(3) among the samples taken for the present study(97%positivity)and banked samples from5-and 15-year old studies(89%positivity).According to the present study,both the porcine astrovirus group 2 and the phage vB_AviM_AVP of Aerococcus could be proxy for airborne viruses of swine buildings.
