Avaliação do potencial probiótico de bactérias lácticas isoladas de leite de búfala

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Mannheimia varigena como agente etiológico de claudicação e lesão na banda coronária em bovinos

Mannheimia varigena was identified as the etiologic agent of lameness and coronary band lesion in 30% of cattle in a farm located in Rio Grande do Sul, Brazil. Swab samples from the lesions were cultured in McConkey Agar and Blood Agar for microbiological identification. Culture growth was submitted to Gram staining and Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) identification. Antimicrobial susceptibility test based on disc diffusion was performed for three antibiotics: ceftiofur, gentamicin and florfenicol. Furthermore, molecular characterization of 16S rDNA gene sequencing was performed and the data was used in a phylogenetic analysis. For that purpose, total DNA was extracted by thermo extraction directly from the bacterial colonies and the polymerase chain reaction (PCR) was performed. Gram-negative Mannheimia varigena strain LBV010/22 was identified as the causative of the lesions. The strain was susceptible to all antibiotics tested. The phylogenetic analysis demonstrated that the analyzed strain is closely related to M. varigena strains from pyelonephritis and respiratory tract. Overall, this is the first report of M. varigena as the causative agent of coronary band injury in bovine. Therefore, our findings show the importance of an accurate microbiological identification of infectious agent in lameness cases in order to prevent the occurrence and perform an appropriate treatment in the future.Mannheimia varigena foi identificada como agente etiológico de claudicação e lesão de banda coronária em 30% dos bovinos de uma fazenda localizada no Rio Grande do Sul, Brasil. Amostras de swab das lesões foram cultivadas em Ágar McConkey e Ágar Sangue para identificação microbiológica. O crescimento da cultura foi submetido à coloração de Gram e identificação por Espectrometria de Massa de Ionização por Dessorção a Laser Assistida por Matriz (MALDI-TOF MS). O teste de suscetibilidade antimicrobiana baseado na difusão em disco foi realizado para três antibióticos: ceftiofur, gentamicina e florfenicol. Além disso, foi realizada a caracterização molecular do sequenciamento do gene 16S rDNA e o resultado utilizado para análise filogenética. Para tanto, o DNA total foi extraído por termoextração diretamente das colônias bacterianas e uma reação em cadeia da polimerase (PCR) foi realizada. Foi identificada como causadora das lesões a cepa gram-negativa de Mannheimia varigena_LBV010/22. Ela foi suscetível a todos os antibióticos testados. A análise filogenética demonstrou que a cepa analisada está intimamente relacionada às M. varigena presentes em pielonefrite e no trato respiratório. No geral, este é o primeiro relato de M. varigena como agente causador de lesão de banda coronária em bovinos. Portanto, nossos achados mostram a importância de uma identificação microbiológica precisa do agente infeccioso nos casos de claudicação, a fim de prevenir a ocorrência e realizar um tratamento adequado no futuro

Streptococcus spp. in Equines - Infection and Antimicrobial Susceptibility Profiles

Background: Empirical antimicrobial prescribing is commonly used in equine veterinary. Therefore, professionals can obtain information about antimicrobial susceptibility profile of the bacterial strains based on veterinary literature. Considering equine infections, Streptococcus spp. are important pathogens that can cause serious damage in horses. Therefore, the aim of this study was to describe the antimicrobial susceptibility testing (AST) and infection profiles of Streptococcus spp. strains isolated from equines with infectious diseases subjected to microbiological analysis.   Materials, Methods & Results: Veterinarians sent 13 samples and culture in Blood and MacConkey Agar were performed. After the incubation period, suspected colonies, which showed significative growth, were analyzed by Gram-staining, biochemical tests, and subjected to confirmatory identification in Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. In vitro AST analysis were performed by disc diffusion method, in accordance with the veterinarians' request. The antimicrobials tested in this study were: ceftiofur, gentamicin, ampicillin, enrofloxacin, amikacin, penicillin, trimethoprim-sulfamethoxazole, ciprofloxacin, doxycycline, vancomycin and metronidazole. The samples included uterine exudate, hock fistula, osteosynthesis exudate, exudate from the guttural pouch, and were originated from animals located in different and distant geographical regions in the cities of Porto Alegre, Pelotas, and Bagé, Rio Grande do Sul, Brazil. Streptococcus dysgalactiae, Streptococcus equi and Streptococcus thoraltensis were the Streptococcus species identified in the samples. S. dysgalactiae was the mainly species found in the uterus samples, while S. thoraltensis, an unusual Streptococcus species, was identified as etiological agent of endometritis in 2 of the analyzed animals. On the other hand, S. equi was found in both the guttural pouch, representing the etiological agent of the strangle case, and in the osteosynthesis exudate, as infectious agent of post-osteosynthesis surgery. The majority of streptococci strains were susceptible to ceftiofur drug. Amikacin and ciprofloxacin, however, were the drugs for which the strains were mainly resistant according to the results. Discussion: The present study provided the AST and infection profile of Streptococcus species related to equine infectious diseases. S. dysgalactiae is considered an unusual bacterium isolated from horses that can be related to endometritis, S. equi is the causative agent of strangles, and S. thoraltensis is unusual in equines. Generally, the observed susceptibility to ceftiofur of the strains analyzed was in agreement with previous results reported in the literature. However, ceftiofur is a third-generation cephalosporin and is considered a critically important antibiotic for human health and its use in veterinary medicine should be cautious. Considering the resistance profile found, Streptococcus spp. can be intrinsically resistant to low drug concentrations of aminoglycosides. Moreover, the emergence and spread of fluoroquinolones resistance may also be due to the acquisition of resistance via horizontal gene transfer. Therefore, the present study described both infection and antimicrobial susceptibility patterns of Streptococcus strains related to equine infectious diseases. Considering the findings, the results found in this study might contribute to the decision-making by veterinarians to further equine treatments. Keywords: antimicrobial susceptibility, pattern, AST, drug, resistant bacteria, horses, veterinarians

Streptococcus spp. in equines : infection and antimicrobial susceptibility profiles

Background: Empirical antimicrobial prescribing is commonly used in equine veterinary. Therefore, professionals can obtain information about antimicrobial susceptibility profile of the bacterial strains based on veterinary literature. Considering equine infections, Streptococcus spp. are important pathogens that can cause serious damage in horses. Therefore, the aim of this study was to describe the antimicrobial susceptibility testing (AST) and infection profiles of Streptococcus spp. strains isolated from equines with infectious diseases subjected to microbiological analysis. Materials, Methods & Results: Veterinarians sent 13 samples and culture in Blood and MacConkey Agar were performed. After the incubation period, suspected colonies, which showed significative growth, were analyzed by Gram-staining, biochemical tests, and subjected to confirmatory identification in Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. In vitro AST analysis were performed by disc diffusion method, in accordance with the veterinarians’ request. The antimicrobials tested in this study were: ceftiofur, gentamicin, ampicillin, enrofloxacin, amikacin, penicillin, trimethoprim-sulfamethoxazole, ciprofloxacin, doxycycline, van¬comycin and metronidazole. The samples included uterine exudate, hock fistula, osteosynthesis exudate, exudate from the guttural pouch, and were originated from animals located in different and distant geographical regions in the cities of Porto Alegre, Pelotas, and Bagé, Rio Grande do Sul, Brazil. Streptococcus dysgalactiae, Streptococ¬cus equi and Streptococcus thoraltensis were the Streptococcus species identified in the samples. S. dysgalactiae was the mainly species found in the uterus samples, while S. thoraltensis, an unusual Streptococcus species, was identified as etiological agent of endometritis in 2 of the analyzed animals. On the other hand, S. equi was found in both the guttural pouch, representing the etiological agent of the strangle case, and in the osteosynthesis exu¬date, as infectious agent of post-osteosynthesis surgery. The majority of streptococci strains were susceptible to ceftiofur drug. Amikacin and ciprofloxacin, however, were the drugs for which the strains were mainly resistant according to the results. Discussion: The present study provided the AST and infection profile of Streptococcus species related to equine infectious diseases. S. dysgalactiae is considered an unusual bacterium isolated from horses that can be related to endometritis, S. equi is the causative agent of strangles, and S. thoraltensis is unusual in equines. Generally, the observed susceptibility to ceftiofur of the strains analyzed was in agreement with previous results reported in the literature. However, ceftiofur is a third-generation cephalosporin and is considered a critically important antibiotic for human health and its use in veterinary medicine should be cautious. Considering the resistance profile found, Streptococcus spp. can be intrinsically resistant to low drug concentrations of aminoglycosides. Moreover, the emergence and spread of fluoroquinolones resistance may also be due to the acquisition of resistance via horizontal gene transfer. Therefore, the present study described both infection and antimicrobial susceptibility patterns of Streptococcus strains related to equine infectious diseases. Considering the findings, the results found in this study might contribute to the decision-making by veterinarians to further equine treatments

Campylobacter fetus in Abomasal Fluid from Spontaneously Aborted Bovine and Ovine Fetuses

Background: Pregnancy losses are a major concern in livestock industry due to their economic impact on producers. Campylobacter fetus subspecies fetus (Cff) and C. fetus subspecies venerealis (Cfv) are directly related to reproductive failures in ruminants. Cff colonizes the gastrointestinal tract of a wide range of hosts leading to abortion, while Cfv is restricted to genital tract being generally associated to infertility in bovine. Considering the great economic losses related to campylobacteriosis in cattle and ovine herds, this study aims to investigate the occurrence of C. fetus, considering Cff and Cfv subspecies, in bovine and ovine spontaneously aborted fetuses in state of Rio Grande do Sul, Brazil.Materials, Methods & Results: In this study, samples of abomasal fluid collected from 30 spontaneously aborted bovine (n = 18) and ovine (n = 12) fetuses were investigated for the detection of Campylobacter fetus throughout conventional PCR. Positive fetuses for C. fetus presence were further analyzed by molecular assays for Cff and Cfv detection, in order to determine subspecies identification. When available, samples of the main organs of the thoracic and abdominal cavities, as well as the brain, skeletal muscle, eyelid, skin, and placenta were collected for further histopathological analyses and bacterial culture, aiming to assess the presence of infection lesions and pathogens in those sites, respectively. Additionally, RT-qPCR assays were also performed for the detection of ruminant pestivirus, in order to detect bovine viral diarrhea cases. Throughout the present methodology, C. fetus was detected in the abomasal fluid samples of 2 bovine fetuses, being both identified as Cfv subspecies by PCR. Histopathological analyses demonstrated that macroscopic and microscopic changes found in the Cfv-positive animals were not either specific or directly related to Campylobacter infections. Moreover, no significant bacterial growth was observed in microbiological culture from the collected tissues, and both fetuses were negative for ruminant pestivirus. Differently, there was no detection of C. fetus in any of the analyzed ovine fetuses.Discussion: Considering that abortion diagnosis rates reported in cattle and sheep industry are highly variable among the published studies, and that abortion diagnoses are commonly inconclusive due to difficulties in sampling methodology and inadequate identification of the pathogen involved, it is important to investigate the etiological causes of abortion the herds for better understanding the causes of pregnancy issues and monitoring their occurrence. In addition, the absence of pathognomonic lesions in the tissues investigated in the histopathological analyses observed in this study strongly suggests that well-known etiological agents commonly associated to abortion, such as Leptospira spp., Toxoplasma spp., Chlamydia spp. and Neospora caninum, are unlikely to be the cause of infection of the analyzed fetuses. Taking this into account, the presence of C. fetus in the abomasal fluid samples from two bovine fetuses demonstrated in the present study suggests the possible association of Cfv not only with infertility, but also with cases of bovine abortion, highlighting the importance of investigating unusual causal agents of abortions in sheep and cattle. Overall, an adequate diagnosis is essential for establishing better prevention strategies to avoid the circulation of abortion-related infectious agents in the herds.Keywords: campylobacteriosis, molecular diagnosis, venereal disease, abortion, reproductive disease

Mycoplasma non-coding RNA: identification of small RNAs and targets

Background: Bacterial non-coding RNAs act by base-pairing as regulatory elements in crucial biological processes. We performed the identification of trans-encoded small RNAs (sRNA) from the genomes of Mycoplama hyopneumoniae, Mycoplasma flocculare and Mycoplasma hyorhinis, which are Mycoplasma species that have been identified in the porcine respiratory system. Results: A total of 47, 15 and 11 putative sRNAs were predicted in M. hyopneumoniae, M. flocculare and M. hyorhinis, respectively. A comparative genomic analysis revealed the presence of species or lineage specific sRNA candidates. Furthermore, the expression profile of some M. hyopneumoniae sRNAs was determined by a reverse transcription amplification approach, in three different culture conditions. All tested sRNAs were transcribed in at least one condition. A detailed investigation revealed a differential expression profile for two M. hyopneumoniae sRNAs in response to oxidative and heat shock stress conditions, suggesting that their expression is influenced by environmental signals. Moreover, we analyzed sRNA-mRNA hybrids and accessed putative target genes for the novel sRNA candidates. The majority of the sRNAs showed interaction with multiple target genes, some of which could be linked to pathogenesis and cell homeostasis activity. Conclusion: This study contributes to our knowledge of Mycoplasma sRNAs and their response to environmental changes. Furthermore, the mRNA target prediction provides a perspective for the characterization and comprehension of the function of the sRNA regulatory mechanisms