Mammary pathogenic Escherichia coli (MPEC) is one of the most common pathogens associated with clinical mastitis. We analyzed isolates obtained from milk samples of cows with clinical mastitis, ...collected from 10 farms in Brazil, to verify molecular and phenotypic characteristics. A total of 192 (4.5%) mammary pathogenic E. coli isolates were obtained from 4,275 milk samples analyzed, but we tested 161. We assigned most of these isolates to E. coli phylogroups B1 (52.8%) and A (36.6%), although phylogroups B2, C, D, E, and unknown also occurred. All isolates were assessed for the presence of several genes encoding virulence factors, such as adhesins (sfaDE, papC, afaBC III, ecpA, fimH, papA, and iha), toxins (hlyA, cnf1, sat, vat, and cdt), siderophores (iroN, irp2, iucD, ireA, and sitA), an invasion protein (ibeA), and serum resistance proteins (traT, KpsMTII, and ompT), and isolates from phylogroups B1, B2, and E showed up to 8 genes. Two isolates harbored the locus of enterocyte effacement (escN+) and lack the bundle-forming pilus (bfpB−) operon, which corresponds to a molecular profile of a subgroup of diarrheagenic E. coli (aEPEC), thus being classified as hybrid MPEC/aEPEC isolates. These isolates displayed a localized adherence-like pattern of adherence in HeLa cells and were able to promote F-actin polymerization underneath adherent bacteria. Based on the pulsed-field gel electrophoresis analyses, considerable genetic variability was observed. A low index of antimicrobial resistance was observed and 2 extended-spectrum β-lactamase–producing E. coli were identified, both harboring blaCTX-M15 gene, and were classified as ST10 and ST993 using multilocus sequence typing. A total of 148 (91.2%) isolates were weak biofilm producers or formed no biofilm. Because raw milk is still frequently consumed in Brazil, the occurrence of virulence factor–encoding genes from extraintestinal or diarrheagenic E. coli added to the presence of extended-spectrum β-lactamase–producing isolates can turn this veterinary medicine problem into a public health concern.
Many efforts have been made to understand the pathogenesis of bovine mastitis to reduce losses and promote animal welfare. Staphylococcus aureus may cause bovine clinical mastitis, but it is mainly ...associated with subclinical infection, which is usually persistent and can easily reoccur. Here, we conducted a comparative genomic analysis between strains of S. aureus causing subclinical infection (Sau170, 302, 1269, 1364), previously sequenced by our group, and two well-characterized strains causing clinical mastitis (N305 and RF122) to find differences that could be linked to mastitis outcome. A total of 146 virulence-associated genes were compared and no appreciable differences were found between the bacteria. However, several nonsynonymous single nucleotide polymorphisms (SNPs) were identified in genes present in the subclinical strains when compared to RF122 and N305, especially in genes encoding host immune evasion and surface proteins. The secreted and surface proteins predicted by in silico tools were compared through multidimensional scaling analysis (MDS), revealing a high degree of similarity among the strains. The comparison of orthologous genes by OrthoMCL identified a membrane transporter and a lipoprotein as exclusive of bacteria belonging to the subclinical and clinical groups, respectively. No hit was found in RF122 and N305 for the membrane transporter using BLAST algorithm. For the lipoprotein, sequences of Sau170, 302, 1269, and 1364 with identities between 68-73% were found in the MDS dataset. A conserved region found only in the lipoprotein genes of RF122 and N305 was used for primer design. Although the polymerase chain reaction (PCR) on field isolates of S. aureus did not validate the findings for the transporter, the lipoprotein was able to separate the clinical from the subclinical isolates. These results show that sequence variation among bovine S. aureus, and not only the presence/absence of virulence factors, is an important aspect to consider when comparing isolates causing different mastitis outcomes.
Escherichia coli is a major pathogen involved in the etiology of environmentally derived bovine mastitis and is characterized by a variety of virulence factors (VF). Mammary infections with E. coli ...have shown a wide range of clinical signs, causing changes in milk (score 1, or mild), abnormal appearance of milk and udder inflammation (score 2, or moderate), and abnormalities in milk, udder inflammation, and systemic signs of illness (score 3, or severe). Nevertheless, to date, the profile of the genes related to the virulence of the pathogen in mammary infections and the severity scores of cases have not been thoroughly elucidated. Therefore, a panel of 18 virulence-encoding genes associated with extra-enteric pathogenicity of E. coli (ExPEC) were investigated in addition to in vitro swimming and swarming motility profiles and antimicrobial susceptibility/resistance patterns among 114 E. coli strains isolated from cows with clinical mastitis and different severity scores. Of 114 clinical cases, 39.5, 54.4, and 6.1% were mild, moderate, and severe, respectively. The main genes related to VF harbored by isolates were adhesins (fimH 100%; ecpA 64.0%, fimA 31.6%), serum resistance (traT 81.6%; ompT 35.1%), siderophores (irp2 9.6%), and hemolysin (hlyA 7%). Among the isolates studied, 99.1% showed in vitro resistance to bacitracin and cloxacillin, and 98.2% to lincosamin. Of the total isolates, 98.2% were considered multidrug resistant based on the multiple antimicrobial resistance index. No significant difference was observed between mean swimming (13.8 mm) and swarming (13.5 mm) motility, as well as severity scores of clinical mastitis and the ExPEC genes studied. The isolation of strains resistant to various antimicrobials, even though tested only in vitro, highlights the importance of rational use of antimicrobials for mastitis treatment. The high prevalence of the genes related to serum resistance (traT and ompT) and adhesion (ecpA) of the pathogen, in addition to main associations between the genes fimH, ecpA, and traT among cows with severity scores of 1 (15%) and 2 (22.6%), indicates that the genes traT, ecpA, and ompT could be further studied as biomarkers of ExPEC for clinical intramammary infections. In addition, the ExPEC genes ompT (protectin), ibe10 (invasin), and ecpA (adhesin) were investigated for the first time among cows with mastitis, where scores of clinical severity were assessed. Results of this study contribute to the characterization of virulence mechanisms and antimicrobial resistance profile of ExPEC variants that affect dairy cows with different scores of clinical mastitis.
We investigate extraintestinal pathogenic genes (ExPEC) related to virulence of Escherichia coli in flies from the dairy environment.
We collected 217 flies from nine dairy farms, which were ...submitted to microbiological culture. Fifty-one E. coli were identified using mass spectrometry. Eleven dipteran families were identified, with a predominance of Muscidae, and a minor frequency of Tachinidae, Drosophilidae, Sphaeroceridae, Ulidiidae, Syrphidae, Chloropidae, Calliphoridae, Sarcophagidae, and Piophilidae. A panel of 16 virulence-encoding genes related to ExPEC infections were investigated, which revealed predominance of serum resistance (traT, 31/51 = 60.8%; ompT, 29/51 = 56.9%), iron uptake (irp2, 17/51 = 33.3%, iucD 11/51 = 21.6%), and adhesins (papC, 6/51 = 11.8%; papA, 5/51 = 9.8%).
Our findings reveal Dipterans from milking environment carrying ExPEC virulence-encoding genes also identified in clinical bovine E. coli-induced infections.
Canine morbillivirus (previously, canine distemper virus, CDV) is a highly contagious infectious disease-causing agent that produces immunosuppressive infections and multiple clinical signs. Canine ...toxoplasmosis is an opportunistic disease characterized by enteric, pulmonary, and neuromuscular signs that might be confused with CDV-induced infections. Rhodococcus equi is a Gram-positive intracellular facultative bacterium that is also opportunistic in nature, and causes pyogranulomatous infections in humans and multiple host animals, although canine rhodococcosis is rare or unrecognized. The pathogenicity of R. equi is intimately related to the presence of plasmid-encoded virulence-associated proteins (Vap). Three host-adapted virulence plasmid types of R. equi have been recognized: the circular pVAPA and pVAPB are associated with equine and porcine strains, respectively, and the recently detected linear pVAPN virulence plasmid is related to bovine isolates. Nevertheless, data regarding the detection of host-adapted virulence plasmid types of R. equi isolated from companion animals are scarce. This report describes a case of an uncommon coinfection due to R. equi, T. gondii and CDV, which was diagnosed in a pet dog with respiratory distress. In this case, CDV most likely induced immunosuppression, which facilitated opportunistic infections by R. equi and T. gondii. The analysis of the virulence profile of R. equi revealed the novel pVAPN plasmid type, initially related to bovine strains. This is the second report of the bovine-associated pVAPN type in a pet dog, with an unusual coinfection with T. gondii and CDV. These findings represent a public health concern due to the close contact between pet animals and their owners, particularly because the pVAPN plasmid type was recently detected in people with HIV/AIDS from the same geographical region.
•First case of combined infection of CDV, Rhodococcus equi and Toxoplasma gondii in a dog with pneumonia.•First description of the novel bovine associated pVAPN type of R. equi causing clinical disease in a dog from Latin America.•Second case of the novel bovine associated pVAPN type of R. equi in a dog.
Intraperitoneal ceftriaxone administration in healthy horses results in high and prolonged peritoneal concentrations. Recent findings suggest that intraperitoneal ceftriaxone might increase survival ...rates in horses affected by peritonitis. The present study aimed to evaluate plasma and peritoneal concentrations of ceftriaxone after intraperitoneal administration in horses with septic peritonitis. Twenty-six horses presenting clinical, laboratorial, and sonographic findings compatible with the disease were included. All horses received daily intraperitoneal ceftriaxone (25 mg/kg bwt) in addition or not with other antibiotics and support therapies. High-performance liquid chromatography was used to determine plasma and peritoneal ceftriaxone concentrations before and after 12 and 24 hours of ceftriaxone administration. Mean plasma concentrations 12 and 24 hours after administration were, respectively, 1.84 ± 0.43 and 0.37 ± 0.07 μg/mL, and mean peritoneal concentrations were 5.7 ± 2.84 and 0.42 ± 0.13 μg/mL. Ceftriaxone concentration was lower in comparison with previous studies in healthy horses and presented under the minimal inhibitory concentration for enterobacteria (≤1 μg/mL) and for gram-positive isolates (≤0.5 μg/mL) at 24 hours. The variation of the results obtained between healthy horses and with septic peritonitis demonstrated that pharmacokinetics/dynamics are different between these patients and suggests the use of an interval of dose of 12 hours.
•Peritonitis remains with high mortality rates in horses.•Intraperitoneal ceftriaxone administration in healthy horses results in high and prolonged peritoneal concentrations.•Intraperitoneal ceftriaxone might increase survival rates in horses.•No profile of the plasmatic and peritoneal concentrations of the ceftriaxone in horses with septic peritonitis is available.
Tetanus in horses: an overview of 70 cases Ribeiro, Márcio G.; Nardi Júnior, Geraldo de; Megid, Jane ...
Pesquisa Veterinária Brasileira,
02/2018, Letnik:
38, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Tetanus is characterized by high case fatality rates in horses. Comprehensive case series studies involving equine tetanus from different geographic areas enable the evaluation of prognosis, efficacy ...of treatment, and control measures. We retrospectively investigated some selected epidemiological data (breed, age, gender, use of the horses, history of vaccination, seasonality, presence of wound/history of surgical procedures, clinical outcomes) and main clinical aspects (clinical signs, incubation period, length of hospitalization, and period between onset signs and hospitalization) in 70 cases of equine tetanus over 1990-2015, with emphasis in the association between these data and the clinical outcomes. High mortality rate (72.9%) was observed in this study. Forty (57.1%) horses presented history of wounds or surgical procedures related with tetanus, represented mainly by lesions in the hind limbs (42.5%), front limbs (15.0%), umbilical infections (7.1%), castration (4.3%), and face wounds (4.3%). Hyperesthesia, limb spasticity, cervical stiffness, tetanic spasms, and restriction of jaw movement were the main consistent clinical signs. Besides no statistical association, all the horses with umbilical infections, wounds in face, prolonged recumbency, sweating, dysphagia/aphagia died, and together with delay between onset of first clinical signs and prompt veterinary assistance (< 5 days) were considered indicative of poor prognosis; whereas there was a significant association (p=0.001) between survival and length of hospitalization > 7 days, seemed as an evidence of good prognosis. The high mortality rate of tetanus, even in horses under specific treatment, highlight the need for early diagnosis, prompt veterinary assistance, and establishment of prophylatic measures in equine farms.
RESUMO: Tétano é caracterizado por elevada mortalidade em equinos. Estudos envolvendo séries de casos da doença provenientes de diferentes áreas geográficas possibilitam avaliar o prognóstico, eficácia do tratamento e ações de controle. Foram avaliados, retrospectivamente, os principais achados epidemiológicos (raça, idade, sexo, uso dos equinos, história de vacinação, sazonalidade, presença de lesões/histórico de procedimentos cirúrgicos e evolução dos casos) e aspectos clínicos (sinais clínicos, período de incubação, tempo de hospitalização e período entre início dos sinais e hospitalização) em 70 casos de tétano em equinos atendidos entre 1990 e 2015, com ênfase na associação entre os dados clínico-epidemiológicos e a evolução dos casos (mortalidade). Foi observada alta mortalidade (72,9%) nos equinos. Do total de equinos, 57,1% apresentavam lesões ou histórico de procedimentos cirúrgicos relacionados com tétano, representados principalmente por lesões em membros posteriores (42,5%), membros anteriores (15,0%), infecções umbilicais (7,1%), castração (4,3%) e lesões de face (4,3%). Hiperestesia, espasticidade dos membros, rigidez de pescoço, espasmos tetânicos e restrição aos movimentos de mandíbula foram os principais sinais clínicos observados. Apesar da ausência de significância estatística, todos os animais com presença de infecções umbilicais, lesões na face, decúbito prolongado, sudorese e disfagia/afagia evoluíram para óbito e, associado ao início dos sinais clínicos e a demora no atendimento (< 5 dias), foram considerados indicativos de prognóstico reservado. Em contraste, foi observada associação significante (p=0,001) entre a sobrevivência dos animais e o tempo de hospitalização maior que 7 dias, considerado uma indicação de bom prognóstico. A elevada mortalidade do tétano, mesmo em equinos tratados, enfatiza a necessidade do diagnóstico precoce, do rápido atendimento veterinário e adoção de medidas profiláticas nos criatórios.
Septic arthritis is a debilitating joint infectious disease of equines that requires early diagnosis and immediate therapeutic intervention to prevent degenerative effects on the articular cartilage, ...as well as loss of athletic ability and work performance of the animals. Few studies have investigated the etiological complexity of this disease, as well as multidrug resistance of isolates. In this study, 60 horses with arthritis had synovial fluid samples aseptically collected, and tested by microbiological culture and in vitro susceptibility test (disk diffusion) using nine antimicrobials belonging to six different pharmacological groups. Bacteria were isolated in 45 (75.0%) samples, as follows: Streptococcus equi subsp. equi (11=18.3%), Escherichia coli (9=15.0%), Staphylococcus aureus (6=10.0%), Streptococcus equi subsp. zooepidemicus (5=8.3%), Staphylococcus intermedius (2=3.3%), Proteus vulgaris (2=3.3%), Trueperella pyogenes (2=3.3%), Pseudomonas aeruginosa (2=3.3%), Klebsiella pneumoniae (1=1.7%), Rhodococcus equi (1=1.7%), Staphylococcus epidermidis (1=1.7%), Klebsiella oxytoca (1=1.7%), Nocardia asteroides (1=1.7%), and Enterobacter cloacae (1=1.7%). Ceftiofur was the most effective drug (>70% efficacy) against the pathogens in the disk diffusion test. In contrast, high resistance rate (>70% resistance) was observed to penicillin (42.2%), enrofloxacin (33.3%), and amikacin (31.2%). Eleven (24.4%) isolates were resistant to three or more different pharmacological groups and were considered multidrug resistant strains. The present study emphasizes the etiological complexity of equine septic arthritis, and highlights the need to institute treatment based on the in vitro susceptibility pattern, due to the multidrug resistance of isolates. According to the available literature, this is the first report in Brazil on the investigation of the etiology. of the septic arthritis in a great number of horses associated with multidrug resistance of the isolates.
A randomized clinical trial was conducted to assess efficacy of intramammary cloxacillin and ampicillin (CLOXIMM), intramammary cefquinome (CEFIMM), and intramuscular cefquinome (CEFIM) to treat ...Streptococcus agalactiae intramammary infections (Trial 1). Subsequently, two treatment groups were extended to assess whether CLOXIMM was not inferior to CEFIMM (Trial 2). Nine farms were included in the study. Milk samples were collected from all quarters of all lactating cows for microbiological identification of S. agalactiae. Positive cows were randomly allocated into four groups: CLOXIMM, CEFIMM, CEFIM, or negative control (CONTROL). Study outcomes were bacteriological cure at 14 (CURE14), 21 (CURE21), and 14 and 21 (CURE1421) days after treatment onset, and somatic cell count. Logistic regression was used to estimate the odds of cure between each treatment and CONTROL. Non-inferiority analysis was performed considering a one-sided 95% confidence interval (CI) and non-inferiority margins (Δ) of 0.10, 0.15, 0.20, and 0.25. Adjusted S. agalactiae bacteriological cure for CLOXIMM, CEFIMM, CEFIM, and CONTROL was 86, 98, 55, and 25% at day 14; 82, 93, 52, and 0% at day 21; and 82, 92, 40, and 0% at days 14 and 21, respectively. Treatment with CLOXIMM and CEFIMM resulted in greater bacteriological cure rates, as compared with CEFIM or CONTROL, which does not justify the use of CEFIM in S. agalactiae eradication programs. The CURE14 difference between CEFIMM and CLOXIMM was of 12.1 percentage points (95% CI: 0.056-0.184). CLOXIMM was considered not inferior to CEFIMM for Δ = 0.20 or 0.25 and inconclusive for Δ = 0.10 or 0.15. Thus, it should be pondered by veterinarians whether an expected 12.1 (5.6-18.4) percentage points increase in cure rate would justify the use of a fourth-generation cephalosporin, as opposed to a combination of traditional IMM drugs (cloxacillin and ampicillin) to treat S. agalactiae subclinical mastitis.
Flooding occurrence is one of the most common phenomena that impact urban areas, and this intensifies during heavy rainfall periods. Knowing the areas with the greatest vulnerability is of paramount ...importance as it allows mitigating actions to be implemented in order to minimize the generated impacts. In this context, this study aimed to use Geographic Information System (GIS) tools to identify the areas with greater flooding vulnerability in Espírito Santo state, Brazil. The study was based on the following methodological steps: (1) a Digital Elevation Model (DEM) acquisition and watersheds delimitation; (2) maximum and accumulated rainfall intensity calculations for the three studied periods using meteorological data; (3) a land use and occupation map reclassification regarding flood vulnerability and fuzzy logic application; (4) an application of Euclidean distance and fuzzy logic in hydrography and water mass vector variables; (5) a flood vulnerability model generation. Based on the found results, it was observed that the metropolitan and coastal regions presented as greater flood vulnerability areas during the dry season, as in these regions, almost all of the 9.18% of the state’s area was classified as highly vulnerable, while during rainy season, the most vulnerable areas were concentrated in Caparaó and in the coastal and immigration and metropolitan regions, as in these regions, almost all of the 12.72% of the state’s area was classified as highly vulnerable. In general, by annually distributing the rainfall rates, a greater flood vulnerability was observed in the metropolitan and coastal and immigration regions, as in these areas, almost all of the 7.72% of the state’s area was classified as highly vulnerable. According to the study, Espírito Santo state was mostly classified as a low (29.15%) and medium (28.06%) flood vulnerability area considering the annual period, while its metropolitan region has a very high flood vulnerability risk. Finally, GIS modeling is important to assist in decision making regarding public management and the employed methodology presents worldwide application potential.
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