Epidemiological Insights into Feline Leukemia Virus Infections in an Urban Cat (Felis catus) Population from Brazil.

Feline leukemia virus (FeLV) is a retrovirus distributed worldwide in domestic cats and with different outcomes (progressive, regressive, abortive, focal). The present study reports an epidemiological survey of FeLV frequency and the evaluation of some risk factors and the two main disease outcomes (progressive and regressive) in an urban cat population from Brazil. A total of 366 cats with sociodemographic information and p27 FeLV antigen test performed were included in the study. FeLV DNA (provirus) in the blood samples of all cats was detected via real-time polymerase chain reaction (qPCR). Plasma samples from 109 FeLV-positive and FeLV-negative cats were also submitted to reverse transcription (RT-qPCR) to determine the FeLV viral load. The results demonstrated that 112 (30.6%) cats were positive through the p27 antigen and/or qPCR. A risk factor analysis demonstrated that cats without vaccination against FeLV (OR 9.9, p < 0.001), clinically ill (OR 2.9, p < 0.001), with outdoors access (OR 2.7, p < 0.001), and exhibiting apathetic behavior (OR 3.1, p < 0.001) were more likely to be infected with FeLV. FeLV-infected cats were also more likely to present with anemia (OR 13, p < 0.001) and lymphoma (OR 13.7, p = 0.001). A comparative analysis of the different detection methods in a subset of 109 animals confirmed FeLV infection in 58 cats, including 38 (65.5%) with progressive, 16 (27.6%) with regressive, and 4 (6.9%) with probably focal outcome diseases. In conclusion, this study demonstrates a high prevalence of FeLV in this urban cat population from Brazil and highlights the need to establish more effective prevention strategies (such as viral testing, vaccination programs, specific care for FeLV-positive cats) to reduce diseases associated with this virus in Brazil.

Canine parvovirus type 2 (CPV-2) serological and molecular patterns in dogs with viral gastroenteritis from southern Brazil.

Canine Parvovirus type 2 (CPV-2) is a highly contagious virus that can cause severe systemic disease with gastroenteric symptoms in dogs, particularly in young puppies. Originating from the feline parvovirus in the late 1970s, it swiftly propagated globally, instigating a pandemic in dogs. Despite vaccination advancements, CPV-2 remains a substantial challenge for veterinary professionals and pet owners. This study aimed to contribute knowledge about the current situation of CPV-2 among dogs in southern Brazil. In this study, the sera of 125 dogs (mostly with gastroenteritis symptoms) were screened for antibodies against CPV-2 and their faeces for the virus itself. The results showed that 40% (50/125) of dogs were infected with CPV-2. Most animals (65.5%) had previously been exposed to CPV-2 (with serotitres equal or above 1:40), and only 37.6% had protective antibody titres equal or above 1:80. The findings have also demonstrated that vaccination against CPV-2 significantly reduced the risk of infection, with positive cases decreasing from 56.9% (unvaccinated) to 2.0% (fully vaccinated). Furthermore, the prevalence of CPV-2 decreased as dogs aged, with younger dogs and those with an incomplete or non-existent vaccination history at the highest risk of infection. In conclusion, this study provides valuable insight into the prevalence and risk factors associated with CPV-2 infection in dogs in southern Brazil, thereby providing valuable knowledge for the improvement of veterinary care and pet health.

Antiviral alternatives against important members of the subfamily Parvovirinae: a review.

Parvoviruses are responsible for multiple diseases, and there is a critical need for effective antiviral therapies. Specific antiviral treatments for parvovirus infections are currently lacking, and the available options are mostly supportive and symptomatic. In recent years, significant research efforts have been directed toward understanding the molecular mechanisms of parvovirus replication and identifying potential targets for antiviral interventions. This review highlights the structure, pathogenesis, and treatment options for major viruses of the subfamily Parvovirinae, such as parvovirus B19 (B19V), canine parvovirus type 2 (CPV-2), and porcine parvovirus (PPV) and also describes different approaches in the development of antiviral alternatives against parvovirus, including drug repurposing, serendipity, and computational tools (molecular docking and artificial intelligence) in drug discovery. These advances greatly increase the likelihood of discoveries that will lead to potent antiviral strategies against different parvovirus infections.

Evolution and Epidemic Spread of the Avian Infectious Bronchitis Virus (IBV) GI-23 in Brazil.

Infectious bronchitis virus (IBV) is a pathogen affecting poultry flocks worldwide. GI-23 is an IBV lineage with a rapid spread into different continents of the world, and it was reported for the first time in South American/Brazilian broiler farms last year. This study aimed to investigate the recent introduction and epidemic spread of IBV GI-23 in Brazil. Ninety-four broiler flocks infected with this lineage were evaluated from October 2021 to January 2023. IBV GI-23 was detected using real-time RT-qPCR, and the S1 gene hypervariable regions 1 and 2 (HVR1/2) were sequenced. S1 complete and HVR1/2 nucleotide sequence datasets were used to carry out phylogenetic and phylodynamic analyses. Brazilian IBV GI-23 strains clustered into two specific subclades (SA.1 and SA.2), both in tree branches with IBV GI-23 from Eastern European poultry-producing countries, suggesting two independent and recent introductions (around 2018). Viral phylodynamic analysis showed that the IBV GI-23 population increased from 2020 to 2021, remaining constant for one year and declining in 2022. S1 amino acid sequences from Brazilian IBV GI-23 presented specific and characteristic substitutions in the HVR1/2 for subclades IBV GI-23 SA.1 and SA.2. This study brings new insights into the introduction and recent epidemiology of IBV GI-23 in Brazil.

Antimicrobial activity of essential oils against Staphylococcus aureus and Staphylococcus chromogenes isolated from bovine mastitis.

Staphylococcus aureus and Staphylococcus chromogenes are pathogens frequently detected in bovine mastitis. Treatment and prevention of this disease have been usually carried on with antimicrobials. However, the emergence of bacterial isolates with antimicrobial resistance has aroused interest in new therapeutic alternatives. Plant essential oils (EOs) have been largely studied as antibacterial treatments. In the present study, EOs from five plants were evaluated for their antibacterial activities against S. aureus and S. chromogenes. Bacterial isolates were obtained in a previous study of clinical cases of bovine mastitis. EOs from lemongrass, eucalyptus, lavender, peppermint, and thyme were obtained by hydrodistillation and their chemical compositions were evaluated by gas chromatography (GC). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for all EOs. The results demonstrated that citral (40.9%), myrcene (24.7%), and geraniol (1.9%) were detected in lemongrass EO; 1,8-cineole (76.9%), α-pinene (8.2%), and ledene (5.1%) in eucalyptus EO; 1,8-cineole (45.2%), camphor (18.2%), and fenchone (14.6%) in lavender EO; L-menthol (38.5%), menthofuran (16.3%), and citronellal (10.6%) in peppermint EO; and thymol (44.2%), p-cymene (24.6%) and 1,8-cineole (9.9%) in thyme EO. More effective antibacterial activities were observed only with the use of lemongrass (MIC and MBC ranging from 0.39 to 3.12 mg/mL and 0.39 to 6.35 mg/mL, respectively) and thyme (MIC and MBC ranging from 0.39 to 1.56 mg/mL and 0.39 to 3.12 mg/mL, respectively). Peppermint, lavender and eucalyptus EOs did not show bactericidal activities. In conclusion, lemongrass and thyme EOs are promising antibacterial alternatives against Staphylococcus species associated with bovine mastitis.

Canine Parvovirus 2 in Free-Living Wild Mammals from Southern Brazil.

Pathogens from domestic canines represent a significant and constant threat to wildlife. This study looked for four common canine pathogens, Babesia vogeli, Ehrlichia canis, Leishmania infantum, and canine parvovirus 2 (CPV-2) in mammals from the Pampa Biome, southern Brazil. Animals killed by vehicular trauma on a road traversing this biome were evaluated over a 1-yr period. Tissues collected from 31 wild mammals and six dogs were further analyzed by specific real-time PCR assays for each pathogen. Babesia vogeli and L. infantum were not detected in any investigated animal. Ehrlichia canis was detected in one dog and CPV-2 in nine animals: four dogs, three white-eared opossums (Didelphis albiventris), one pampas fox (Lycalopex gymnocercus), and one brown rat (Rattus norvegicus). These results demonstrate the occurrence of important carnivore pathogens (E. canis and CPV-2) in domestic dogs and wild mammals from the Pampa Biome in southern Brazil.

Canine parvovirus type 2 vaccines in Brazil: Viral load in commercial vaccine vials and phylogenetic analysis of the vaccine viruses.

Canine parvovirus type 2 (CPV-2) is the etiological agent of a highly contagious and frequently fatal disease in dogs. Live attenuated vaccines (LAV) are recommended to prevent and control this disease. Commercial vaccines are typically produced with CPV-2 strains adapted to cell culture and usually non-pathogenic. The present study aimed to determine the viral load of CPV-2 vaccines commercially available in Brazil and to characterize the vaccine virus by DNA analysis of its capsid gene. The results demonstrated that all vaccine strains presented high homology of the VP2 gene and they were all closely related to the original CPV-2 strains. However, vaccine strains presented several differences in comparison with field strains currently circulating in Brazil. Seventy-one vials contained viral loads ranging from 7.4E3 to 4.9E10 DNA copies/ml. Nine vials did not contain any detectable CPV-2 DNA. In conclusion, there are genetic and antigenic differences among CPV-2 vaccines and field strains. Additionally, some vaccines have been commercialized with low titers of CPV-2. It is important to improve the quality of the vaccines to prevent or reduce the spread of CPV-2 in Brazil.

Infecção cervical por papilomavírus humano em mulheres idosas / Cervical human papillomavirus infection in older women

Resumo Objetivo Investigar a presença de infecção cervical pelo papilomavírus humano (HPV, human papillomavirus) em mulheres idosas e fatores relacionados. Método Trata-se de um estudo transversal, retrospectivo e descritivo, com abordagem quantitativa. A amostra foi constituída por 106 mulheres com idade igual ou superior a 60 anos atendidas em serviços de saúde pública de uma cidade do Sul do Brasil, as quais realizaram coleta de material cervical para análise citológica e detecção molecular do DNA do HPV, bem como levantamento de dados clínicos e sociodemográficos por meio de um questionário padronizado e requisição do exame citopatológico. Resultados A idade das pacientes variou entre 60 e 82 anos, com média de 64,9 ± 5,1. O HPV foi detectado em 14 (13,2%) idosas avaliadas no estudo e 8 tipos virais foram identificados, a maioria (n=7; 87,5%) de alto risco oncogênico. Observou-se, por análise de qui-quadrado, que casos HPV positivos possuem associação com maior número de parceiros sexuais (p= 0,018). Na citologia, a maioria das mulheres (n=102; 96,2%) apresentou resultado negativo para lesão intraepitelial ou malignidade e duas (1,8%) apresentaram citologia alterada, mas destas, nenhuma apresentou infecção por HPV no teste molecular. Das 10 mulheres avaliadas em duas visitas, sete (70%) não apresentaram infecção pelo HPV em ambas as avaliações, duas (20%) eliminaram a infecção pelo HPV e uma (10%) apresentou conversão para positividade. Nenhuma delas apresentou infecção persistente. Conclusão Mulheres idosas estão suscetíveis à infecção por HPV e às lesões causadas por esse vírus, por isso devem manter o rastreamento citológico.

Abstract Objective To investigate the presence of cervical infection by human papillomavirus (HPV) and associated factors in older women Method A cross-sectional, retrospective descriptive study with a quantitative approach was conducted. The sample comprised 106 women aged 60 years or over, seen at public health services of a city in southern Brazil, who underwent cervical cell collection for cytological analysis and molecular detection of HPV DNA. Clinical and sociodemographic data were collected using a standardized questionnaire and from Pap test result Results Patient age was 60-82 years, with a mean of 64.9 ± 5.1 years. HPV was detected in 14 (13.2%) of the study participants and 8 viral types were identified, the majority (n=7; 87.5%) of high oncogenic risk. Chi-square analysis revealed that positive HPV cases were associated with a higher number of sexual partners (p= 0.018). On cytology, most of the women (n=102; 96.2%) had a negative result for intraepithelial lesion or malignancy, and two (1.8%) had abnormal cytology, but neither were positive for HPV infection on molecular testing. Of the 10 women evaluated at two visits, seven (70%) tested negative for HPV infection on both evaluations, two (20%) eliminated the HPV infection, and one (10%) showed conversion to positive infection status. None of the cases had persistent infection. Conclusion Older women are susceptible to HPV infection and to the lesions caused by the virus. This group should therefore continue regular cytological screening.

Emergence and molecular characterization of the avian infectious bronchitis virus GI-23 in commercial broiler farms from South America.

Avian infectious bronchitis virus (IBV) is the etiological agent of a highly contagious disease in the poultry industry. The spike protein (S1 subunit) is responsible for the molecular diversity of the virus and many genetic types, and lineages are described worldwide. IBV genetic type I-strain 23 (GI-23) has spread across different continents (including Asia, Europe and Africa), causing multiple outbreaks and severe economic losses throughout the poultry industry in the last decade. The present study aimed to report the emergence and molecular characterization of GI-23 in South Brazil, being detected for the first time in South America. Eighty-two broiler flocks presenting clinical suspicion of infectious bronchitis were selected for this study. Tracheal, renal and intestinal samples were collected for IBV detection and genotyping. A total of 57 flocks were positive for IBV by generic RT-qPCR targeting 5' untranslated region and 31 also tested positive for GI-11 by a specific RT-qPCR targeting S1 gene for this lineage. The remaining 26 IBV-positive samples were genotyped by partial and one by complete S1 gene/protein sequencing. Phylogenetic analysis demonstrated that all of them clustered into a specific branch of the GI-23. S1 protein sequence analysis evidenced that all Brazilian GI-23 IBVs had the two characteristic amino acid substitutions A93T and S/H118P/L, but other changes were also observed, such as S37F (n = 21; 81%), G117S (n = 17, 65%), P122S (n = 16; 61%) and W71R (n = 9; 35%). This study brings new insights into the epidemiology of the IBV GI-23 in the world, highlighting its emergence and molecular characteristics in Brazil, South America.

Emergence, Dissemination and Antimicrobial Resistance of the Main Poultry-Associated Salmonella Serovars in Brazil.

Salmonella infects poultry, and it is also a human foodborne pathogen. This bacterial genus is classified into several serovars/lineages, some of them showing high antimicrobial resistance (AMR). The ease of Salmonella transmission in farms, slaughterhouses, and eggs industries has made controlling it a real challenge in the poultry-production chains. This review describes the emergence, dissemination, and AMR of the main Salmonella serovars and lineages detected in Brazilian poultry. It is reported that few serovars emerged and have been more widely disseminated in breeders, broilers, and layers in the last 70 years. Salmonella Gallinarum was the first to spread on the farms, remaining as a concerning poultry pathogen. Salmonella Typhimurium and Enteritidis were also largely detected in poultry and foods (eggs, chicken, turkey), being associated with several human foodborne outbreaks. Salmonella Heidelberg and Minnesota have been more widely spread in recent years, resulting in frequent chicken/turkey meat contamination. A few more serovars (Infantis, Newport, Hadar, Senftenberg, Schwarzengrund, and Mbandaka, among others) were also detected, but less frequently and usually in specific poultry-production regions. AMR has been identified in most isolates, highlighting multi-drug resistance in specific poultry lineages from the serovars Typhimurium, Heidelberg, and Minnesota. Epidemiological studies are necessary to trace and control this pathogen in Brazilian commercial poultry production chains.

Molecular survey of porcine respiratory disease complex pathogens in Brazilian wild boars.

Wild boar (Sus scrofa) is an exotic invasive species in Brazil and may be a reservoir for several pathogens, including those related to the porcine respiratory disease complex (PRDC), a critical infectious disease in pig production. The objective of this study was to investigate viral and bacterial pathogens related to PRDC in free-living wild boars from Brazil. Eighty animals were examined in search of genomes of porcine circovirus 2 (PCV2), Torque teno Sus virus 1a (TTSuV1a) and 1b (TTSuV1b), Influenza A virus (IAV), Actinobacillus pleuropneumoniae, Glaesserella parasuis, Pasteurella multocida, and Mycoplasma hyopneumoniae. The results demonstrated that 57.5% (46/80) of the animals had at least one detected pathogen, and 11.3% of them (9/80) were co-infected. TTSuV1a was the most prevalent genome, for which risk factors were associated with increased contact between wild boars and other animals. The other pathogens were detected at much lower frequencies or not detected (M. hyopneumoniae and IAV). An additional IAV serology search identified H1N1pdm09 antibodies in 35.5% (16/45) of the wild boars, bringing concern related to public health. In conclusion, wild boars are infected with pathogens that cause swine diseases, so their eventual contact with domestic pigs might risk animal production in Brazil.

Polymerase chain reaction and loop-mediated isothermal amplification targeting lic13162, lic20239, and lipL32 genes for leptospirosis diagnosis.

Leptospirosis is a zoonotic disease caused by pathogenic species of Leptospira. Due to the similarity with clinical signs of other febrile diseases, early diagnosis remains challenging. Real-time PCR has been used for direct detection of Leptospira, but it requires thermocyclers and highly trained personnel. Loop-mediated isothermal amplification (LAMP) is a simple and rapid DNA-based assay. Therefore, here we have developed PCR and LAMP assays targeting two novel genes, lic13162 and lic20239, and also lipL32 gene to detect pathogenic Leptospira. Analytical and diagnostic performances were compared with bacterial isolates (including different Leptospira species and serovars) and clinical samples. The results demonstrated that PCR assays targeting lic13162 and lic20239 were successful to amplify Leptospira, but LAMP not. However, both PCR and LAMP targeting lipL32 could detect pathogenic Leptospira. LAMP lipL32 could be performed in 30 min with a detection limit of 156 cells/mL. Diagnostic performance of lipL32-LAMP presented 84.2% sensitivity and 93.2% specificity. In conclusion, lipL32 PCR and LAMP are effective methods to detect pathogenic Leptospira directly from clinical samples.

Molecular phylogenetic assessment of the canine parvovirus 2 worldwide and analysis of the genetic diversity and temporal spreading in Brazil.

Canine parvovirus type 2 (CPV-2) is a relevant pathogen for dogs and causes a severe disease in carnivore species. CPV-2 reached pandemic proportions after the 1970s with the worldwide dissemination, generating antigenic and genetic variants (CPV-2a, CPV-2b, and CPV-2c) with different pathobiology in comparison with the original type CPV-2. The present study aimed to assess the current global CPV-2 molecular phylogeny and to analyze genetic diversity and temporal spreading of variants from Brazil. A total of 284 CPV-2 whole-genome sequences (WGS) and 684 VP2 complete genes (including 23 obtained in the present study) were compared to analyze phylogenetic relationships. Bayesian coalescent analysis estimated the time to the most recent common ancestor (tMRCA) and the population dynamics of the different CPV-2 lineages in the last decades. The WGS phylogenetic tree demonstrated two main clades disseminated worldwide today. The VP2 gene tree showed a total of four well-defined clades distributed in different geographic regions, including one with CPV-2 sequences exclusive from Brazil. These clades do not have a relationship with the previous classification into CPV-2a, CPV-2b, and CPV-2c, despite some having a predominance of one or more antigenic types. Temporal analysis demonstrated that the main CPV-2 clades evolved within a few years (from the 1980s to 1990s) in North America and they spread worldwide afterwards. Population dynamics analysis demonstrated that CPV-2 presented a major dissemination increase at the end of the 1980s / beginning of the 1990s followed by a period of stability and a second minor increase from 2000 to 2004.

Recent molecular evolution of hepatitis B virus genotype F in Latin America.

The evolution of hepatitis B virus genotype F (HBV-F) in Latin America is not completely understood. The aim of this study was to evaluate the molecular evolution of HBV-F in Latin America by comparing 224 whole-genome sequences. Bayesian coalescent analysis was performed to estimate the time to the most recent common ancestor. Four main clades were found, dating from between 1245 and 1730. In addition, four subclades were identified, dating to between 1705 and 1801. The overall effective population size of HBV-F grew in the 18th century and showed an initial expansion outward from Venezuela to other countries from Latin America. Although HBV-F originated thousands of years ago, circulating strains of HBV-F appear to have spread in recent centuries, particularly in the 18th and 19th centuries. The new molecular data provide valuable information for characterizing the evolution of Native American HBV-F in recent centuries.

Species identification and antimicrobial susceptibility profile of bacteria associated with cow mastitis in southern Brazil / Identificação de espécies e perfil de suscetibilidade aos antimicrobianos de bactérias associadas à mastite bovina no sul do Brasil

Bovine mastitis is the most common disease in dairy cattle and responsible for economic losses in the milk industry. The present study aimed to identify the main species and to evaluate the antimicrobial susceptibility of bacterial isolates from cow herds with mastitis in dairy farms from southern Brazil. A total of 107 milk samples were collected from different cow herds in one important dairy producing region in southern Brazil, including farms located in ten cities from the Northeast region in the Rio Grande do Sul state. Bacterial strains were isolated and submitted to presumptive identification by classical bacteriological methods. Bacterial species were also identified by MALDI-TOF MS and antimicrobial susceptibility testing was performed with 12 antimicrobials commonly used in dairy farms. Fifty-one bacterial strains were isolated and the presumptive identification demonstrated the occurrence of Staphylococcus spp. (82.3%), Bacillus spp. (3.9%), Klebsiella spp. (3.9%), Streptococcus spp. (3.9%), Corynebacterium sp. (2%), Enterococcus sp. (2%) and Serratia sp. (2%). Forty-one isolates were successfully identified in the MALDI-TOF analysis, including 35 isolates from eleven different bacterial species. Importantly, there were eight different Staphylococcus species, with a high frequency of Staphylococcus chromogenes (48.6%) and Staphylococcus aureus (20%). Overall, bacterial isolates demonstrated resistance to penicillin (46.3%), tetracycline (39%), amoxicillin (36.6%), ampicillin (34.1%) and sulfamethoxazole/trimethoprim (31.7%). Enrofloxacin was the unique antimicrobial that all isolates were susceptible. In addition, there were six multidrug resistant isolates (five S. chromogenes and one S. aureus). This study highlights that bacterial pathogens with resistance to several antimicrobials were identified in cows from dairy farms in a very important milk producing region located in southern Brazil. Microbial identification of the bovine mastitis pathogens and determination of the antimicrobial profile is necessary for the rational use of the medicines.(AU)

A mastite bovina é a doença mais comum em gado leiteiro e responsável por perdas econômicas na indústria de laticínios. O presente estudo teve como objetivo identificar as principais espécies e avaliar a suscetibilidade antimicrobiana de isolados bacterianos de rebanhos bovinos com mastite em fazendas leiteiras no sul do Brasil. Um total de 107 amostras de leite foram coletadas em diferentes rebanhos bovinos em uma importante região produtora de leite do sul do Brasil, incluindo fazendas localizadas em 10 cidades da região Nordeste do estado do Rio Grande do Sul. As cepas bacterianas foram isoladas e submetidas à identificação presuntiva por métodos bacteriológicos clássicos. A identificação bacteriana foi confirmada por MALDI-TOF MS e o teste de sensibilidade antimicrobiana foi realizado com antimicrobianos comumente usados em fazendas leiteiras. Cinquenta e uma cepas bacterianas foram isoladas e a identificação presuntiva demonstrou a ocorrência de Staphylococcus spp. (82,3%), Bacillus spp. (3,9%), Klebsiella spp. (3,9%), Streptococcus spp. (3,9%), Corynebacterium sp. (2%), Enterococcus sp. (2%) e Serratia sp. (2%). Os 41 isolados foram identificados com sucesso na análise MALDI-TOF, incluindo 35 isolados de onze espécies bacterianas diferentes. É importante ressaltar que houve a ocorrência de oito espécies diferentes de Staphylococcus, com alta frequência de Staphylococcus chromogenes (48,6%) e Staphylococcus aureus (20%). No geral, os isolados bacterianos tiveram alta resistência à penicilina (46,3%), tetraciclina (39%), amoxicilina (36,6%), ampicilina (34,1%) e sulfametoxazol/trimetoprima (31,7%). A enrofloxacina foi o único antimicrobiano que todos os isolados foram suscetíveis. Além disso, havia seis isolados multirresistentes (cinco S. chromogenes e um S. aureus). Este estudo destaca que os patógenos bacterianos com resistência aos antimicrobianos estão presentes em fazendas leiteiras de subsistência em uma importante região produtora no sul do Brasil. É necessário o monitoramento constante dos patógenos da mastite bovina e a determinação de seu perfil antimicrobiano para o uso racional dos medicamentos.(AU)

Species identification and antimicrobial susceptibility profile of bacteria associated with cow mastitis in southern Brazil / Identificação de espécies e perfil de suscetibilidade aos antimicrobianos de bactérias associadas à mastite bovina no sul do Brasil

Bovine mastitis is the most common disease in dairy cattle and responsible for economic losses in the milk industry. The present study aimed to identify the main species and to evaluate the antimicrobial susceptibility of bacterial isolates from cow herds with mastitis in dairy farms from southern Brazil. A total of 107 milk samples were collected from different cow herds in one important dairy producing region in southern Brazil, including farms located in ten cities from the Northeast region in the Rio Grande do Sul state. Bacterial strains were isolated and submitted to presumptive identification by classical bacteriological methods. Bacterial species were also identified by MALDI-TOF MS and antimicrobial susceptibility testing was performed with 12 antimicrobials commonly used in dairy farms. Fifty-one bacterial strains were isolated and the presumptive identification demonstrated the occurrence of Staphylococcus spp. (82.3%), Bacillus spp. (3.9%), Klebsiella spp. (3.9%), Streptococcus spp. (3.9%), Corynebacterium sp. (2%), Enterococcus sp. (2%) and Serratia sp. (2%). Forty-one isolates were successfully identified in the MALDI-TOF analysis, including 35 isolates from eleven different bacterial species. Importantly, there were eight different Staphylococcus species, with a high frequency of Staphylococcus chromogenes (48.6%) and Staphylococcus aureus (20%). Overall, bacterial isolates demonstrated resistance to penicillin (46.3%), tetracycline (39%), amoxicillin (36.6%), ampicillin (34.1%) and sulfamethoxazole/trimethoprim (31.7%). Enrofloxacin was the unique antimicrobial that all isolates were susceptible. In addition, there were six multidrug resistant isolates (five S. chromogenes and one S. aureus). This study highlights that bacterial pathogens with resistance to several antimicrobials were identified in cows from dairy farms in a very important milk producing region located in southern Brazil. Microbial identification of the bovine mastitis pathogens and determination of the antimicrobial profile is necessary for the rational use of the medicines.

A mastite bovina é a doença mais comum em gado leiteiro e responsável por perdas econômicas na indústria de laticínios. O presente estudo teve como objetivo identificar as principais espécies e avaliar a suscetibilidade antimicrobiana de isolados bacterianos de rebanhos bovinos com mastite em fazendas leiteiras no sul do Brasil. Um total de 107 amostras de leite foram coletadas em diferentes rebanhos bovinos em uma importante região produtora de leite do sul do Brasil, incluindo fazendas localizadas em 10 cidades da região Nordeste do estado do Rio Grande do Sul. As cepas bacterianas foram isoladas e submetidas à identificação presuntiva por métodos bacteriológicos clássicos. A identificação bacteriana foi confirmada por MALDI-TOF MS e o teste de sensibilidade antimicrobiana foi realizado com antimicrobianos comumente usados em fazendas leiteiras. Cinquenta e uma cepas bacterianas foram isoladas e a identificação presuntiva demonstrou a ocorrência de Staphylococcus spp. (82,3%), Bacillus spp. (3,9%), Klebsiella spp. (3,9%), Streptococcus spp. (3,9%), Corynebacterium sp. (2%), Enterococcus sp. (2%) e Serratia sp. (2%). Os 41 isolados foram identificados com sucesso na análise MALDI-TOF, incluindo 35 isolados de onze espécies bacterianas diferentes. É importante ressaltar que houve a ocorrência de oito espécies diferentes de Staphylococcus, com alta frequência de Staphylococcus chromogenes (48,6%) e Staphylococcus aureus (20%). No geral, os isolados bacterianos tiveram alta resistência à penicilina (46,3%), tetraciclina (39%), amoxicilina (36,6%), ampicilina (34,1%) e sulfametoxazol/trimetoprima (31,7%). A enrofloxacina foi o único antimicrobiano que todos os isolados foram suscetíveis. Além disso, havia seis isolados multirresistentes (cinco S. chromogenes e um S. aureus). Este estudo destaca que os patógenos bacterianos com resistência aos antimicrobianos estão presentes em fazendas leiteiras de subsistência em uma importante região produtora no sul do Brasil. É necessário o monitoramento constante dos patógenos da mastite bovina e a determinação de seu perfil antimicrobiano para o uso racional dos medicamentos.

Temporal and geographic spreading of hepatitis B virus genotype A (HBV-A) in Brazil and the Americas.

Hepatitis B virus genotype A (HBV-A) is disseminated in different countries around the world. It presents a high genetic diversity and is classified into seven subgenotypes (A1-A7). HBV-A1 and HBV-A2 are the most frequent and spread in almost all American countries. This study aimed to evaluate the molecular epidemiology of these two subgenotypes, with a special focus on the temporal and geographic spreading in the Americas and Brazil. Bayesian coalescent analyses with HBV-A1 and HBV-A2 whole-genome sequences were performed to study viral phylodynamic and phylogeography. HBV-A1 evolutionary history demonstrated that it was initially disseminated from Africa to other continents probably after the 1400s and mainly in the 17th-18th centuries. The whole viral population grew between the 1700s-1900s and then reached a stationary phase. In Brazil, HBV-A1 common ancestors dated back to the 1600s with successive introductions between the 17th-18th centuries. In contrast, HBV-A2 spread from Europe to other continents after the 1800s, with an increase in the viral population over decades. It was introduced in the 20th century in America and between the 1950s-1970s in Brazil, presenting a high increase in the viral population from the 1970s to the 1980s. The circulation continents for HBV-A1 are Africa and America, while for HBV-A2 are Europe and America. HBV-A is one of the predominant genotypes in America (including Brazil) because of the early introduction by human migration processes of the subgenotypes A1 and A2 between the 16th and 20th centuries and the continuous spreading inside the continent over time.

Hepatitis B virus genotypes in Brazil: Introduction and dissemination.

Hepatitis B is a viral infectious disease highly spread worldwide with a long evolutionary history associated with human migrations through the continents and countries. Hepatitis B virus (HBV) was disseminated probably from Africa and diverged into ten genotypes (HBV-A to HBV-J) distributed around the world. In Brazil, almost all HBV genotypes were already reported, with a predominance of three ones: A (52.1%), D (36.8%), and F (7.7%). This review aimed to evaluate the introduction and dissemination of the main HBV genotypes and subgenotypes in Brazil over the last centuries to explain the current epidemic scenario. The highest frequency of HBV-A is a consequence of the introduction and spreading of HBV-A1 in the 16th to 19th centuries due to the African slave trade, but the more recent introduction of HBV-A2 from Europe also contributed to the current situation. HBV-D is the second most frequent genotype because it was consecutively introduced by migrations from Europe (mainly subgenotype D3, but also D2) and the Middle East (D1) in the 19th to 20th centuries. On contrary, HBV-F (F1a, F1b, F2a, F2b, F3, and F4) was disseminated by the Amerindians in all South American countries, including Brazil, by migrations inside the continent for more than three centuries ago. Other HBV genotypes are rare and eventually frequent in some human groups because of the dissemination by very specific epidemiological routes. In conclusion, the current scenario of the HBV epidemics is a consequence of the introduction and dissemination of some subgenotypes from the three main genotypes A, D, and F over the last five centuries.

Dissemination and evolution of SARS-CoV-2 in the early pandemic phase in South America.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic spread rapidly and this scenario is concerning in South America, mainly in Brazil with more than seven million cases of infection. Three major pandemic lineages/clades could be identified along with SARS-CoV-2 dissemination (G, GR, and GH) in the Americas. These clades differ according to their genomic characteristics, virulence, and spreading times. The present study describes the main clades and the respective temporal spreading analyses based on SARS-CoV-2 whole-genome sequences (WGS) from South America, obtained in the early pandemic phase (from March 1 to May 31 in 2020). SARS-CoV-2 WGSs with available information from country and year of sampling were obtained from different countries and the main clades were identified and analyzed independently with a Bayesian approach. The results demonstrated the prevalence of clades GR (n = 842; 54.6%), G (n = 529; 34.3%), and GH (n = 171; 11.1%). The frequencies of the clades were significantly different between South American countries. Clade G was the most prevalent in Ecuador, Suriname, and Uruguay, clade GR in Argentina, Brazil, and Peru, and clade GH in Colombia. The phylodynamic analysis indicated that all these main lineages increased viral spreading from February to early March and after an evolutionary stationary phase was observed. The decrease observed in the virus dissemination was directly associated to the reduction of social movement after March. In conclusion, these data demonstrated the current predominance of clades G, GR, and GH in South America because of the early dissemination of them in the first pandemic phase in South America.