Microbial Complexity of Oral Cavity of Healthy Dogs Identified by Mass Spectrometry and Next-Generation Sequencing

The high complexity of the oral microbiota of healthy dogs and the close exposure of humans to companion animals represent a risk of the transmission of potential zoonotic microorganisms to humans, especially through dog bites, including multidrug-resistant ones. Nonetheless, a limited number of comprehensive studies have focused on the diversity of the microorganisms that inhabit the oral cavities of healthy dogs, particularly based on modern molecular techniques. We investigated bacterial and fungal organisms in the oral cavities of 100 healthy dogs based on a combination of conventional and selective microbiological culture, mass spectrometry (MALDI-TOF MS), and next-generation sequencing. In addition, in vitro antimicrobial susceptibility patterns of isolates and mecA resistance gene were assessed. A total of 213 bacteria and 20 fungi were isolated. Staphylococcus pseudintermedius (40/100 = 40%), α-hemolytic Streptococcus (37/100 = 37%), and Pasteurella stomatis (22/100 = 22%) were the most prevalent bacteria diagnosed by microbiological culture and MALDI-TOF MS, whereas Aspergillus (10/100 = 10%) was the most common fungi identified. Based on next-generation sequencing of selected 20 sampled dogs, Porphyromonas (32.5%), Moraxella (16.3%), Fusobacterium (12.8%), Conchiformibius (9.5%), Bergeyella (5%), Campylobacter (3.8%), and Capnocytophaga (3.4%) genera were prevalent. A high multidrug resistance rate was observed in Staphylococcus pseudintermedius isolates, particularly to azithromycin (19/19 = 100%), penicillin (15/19 = 78.9%), and sulfamethoxazole/trimethoprim (15/19 = 78.9%). In addition, the mecA resistance gene was detected in 6.1% (3/49) of coagulase-positive staphylococci. Here, we highlight the microbial complexity of the oral mucosa of healthy dogs, including potential zoonotic microorganisms and multidrug-resistant bacteria, contributing with the investigation of the microbiota and antimicrobial resistance patterns of the microorganisms that inhabit the oral cavity of healthy dogs.

Risk factors associated with faecal carriage of extended-spectrum cephalosporin-resistant Escherichia coli among dogs in Southeast Brazil

Faecal carriage of extended-spectrum cephalosporin-resistant Escherichia coli (ESC-R E. coli) in dogs has been reported worldwide and can reduce the effectiveness of treatments against bacterial infections. However, the drivers that influence faecal carriage of ESC-R E. coli in dogs are poorly understood. The aims of this study were to estimate the prevalence of ESC-R E. coli among dogs prior to their admission to a veterinary teaching hospital and to identify risk factors associated with the faecal carriage of ESC-R E. coli. Rectal swabs (n = 130) were collected from dogs and screened for ESC-R E. coli using MacConkey agar supplemented with cefotaxime (2 μg/mL). E. coli species was confirmed by MALDI-TOF and screening of extended-spectrum beta-lactamase (ESBL) genes was conducted by multiplex PCR. Questionnaires were completed by each dog's owner to test several human and dog characteristics associated with ESC-R E. coli. The prevalence of faecal carriage of ESC-R E. coli was 9.2 % and 67 % of ESC-R E. coli isolates harboured ESBL genes including CTX-M alone or in combination with TEM. All ESC-R E. coli isolates were resistant to ceftriaxone, cefpodoxime, and cefotaxime and were susceptible to cefoxitin and carbapenems. The likelihood of carrying ESC-R E. coli was 15 times higher (OR = 14.41 [95 % CI: 1.80-38.02], p < 0.01) if the dog was treated with antibiotics 3-12 months prior to sampling and 8 times higher (OR = 7.96 [95 % CI: 2.96-92.07], p < 0.01) if the dog had direct contact with livestock, but 15 times lower (OR = 0.07 [95 % CI: 0.01-0.32], p < 0.01) if the dog was dewormed during the previous year. Our findings confirm the faecal carriage of ESC-R E. coli in subclinical dogs and call for further investigation regarding the impact of deworming on antibiotic-resistant bacteria in companion animals.

Putative virulence factors of extra-intestinal Escherichia coli isolated from bovine mastitis with different clinical scores

We investigated the genes kpsMTII, iucD, sfaDE, afaBC, papA and papC, (proposed to be involved in extra-intestinal pathogenic Escherichia coli-ExPEC), phylogroup classification and the in vitro swimming and swarming motility in 50 E. coli isolated from bovine mastitis with different clinical severity scores (mild, moderate and severe). The aforementioned genes were detected in 12 (n = 12/50; 24·0%) isolates. kpsMTII and iucD were the most frequent genes identified in six (n = 6/50; 12·0%) and four (n = 4/50; 8·0%) of the isolates, respectively. In only one (n = 1/50; 2·0%) isolate, more than one gene was simultaneously identified: iucD and kpsMTll were detected whereas sfaDE and afaBC were not detected. Mild, moderate and severe clinical signs were observed in 40·0% (n = 20/50), 28·0% (n = 14/50) and 32·0% (n = 16/50) of the cases. Commensal phylogroups B1 (n = 19/50; 38·0%) and A (n = 19/50; 38·0%) were prevalent; whereas pathogenic phylogroups B2 and D were observed in only 10·0% (n = 5/50). Swarming and swimming motilities were observed in 90·0% (n = 45/50) and 68·0% (n = 34/50) of the isolates, respectively; and there was a significant association (P = 0·0036) between swarming motility and severe clinical cases (score 3). To the best of our knowledge, this is the first study where clinical severity of bovine mastitis cases and the genes proposed to classify ExPEC were assessed in relation to swarming and swimming motility. SIGNIFICANCE AND IMPACT OF THE STUDY: Escherichia coli is classified as extra-intestinal (ExPEC) when strains contain at least two of the genes kpsMTII, iucD, sfaDE, afaBC and papA and/or papC. We investigated in vitro motility and the presence of these genes in 50 E. coli isolated from bovine mastitis with different clinical scores (mild, moderate and severe). Clinical severity was not associated with the genes studied. Swarming motility was associated with severe cases (score 3) of clinical mastitis. Results of this study contribute to a better understanding of the factors that determine the severity of clinical mastitis.

Pre-Multidrug-Resistant Mycobacterium tuberculosis Infection Causing Fatal Enteric Disease in a Dog from a Family with History of Human Tuberculosis

This report describes a fatal case of a pet dog with major enteric signs owned by a family that has experienced cases of pulmonary tuberculosis (TB) in the household. Clinical and epidemiological aspects, imaging data, microbiological, haematological and histopathological examinations were assessed to diagnosis of disease. gyrB-RFLP, spoligotyping and MIRU-VNTR allowed molecular detection of M. tuberculosis strain from S family. The resazurin microtiter assay indicated that all isolates were resistant to isoniazid, ethambutol, ciprofloxacin, ofloxacin, streptomycin and amikacin. The public health concerns related to canine tuberculosis and risk of the dissemination by pets of M. tuberculosis pre-multidrug-resistant (PMD) to isoniazid, ethambutol and other first-line drugs used in human therapy of TB are discussed. We believe this to be the first report of PMD M. tuberculosis infection in a dog presenting mainly enteric manifestation, confirmed as S lineage by molecular methods, owned by a family in which TB has spread in the household for generations.

Trueperella pyogenes multispecies infections in domestic animals: a retrospective study of 144 cases (2002 to 2012)

BACKGROUND

Formerly, Arcanobacterium pyogenes was recently renamed Trueperella pyogenes. This opportunistic bacterium is related to miscellaneous pyogenic infections in animals. Most studies involving T. pyogenes are case reports, whereas few surveys have focused the major aspects of T. pyogenes infections involving a case series study design.

OBJECTIVE

The aim of this study was to retrospectively evaluate selected epidemiological and clinical aspects, as well as the in vitro antimicrobial susceptibility pattern of 144 cases of T. pyogenes infections among domestic animals from 2002 to 2012.

ANIMALS AND METHODS

T. pyogenes was isolated from different clinical specimens from cattle, goats, sheep, pigs, horses, dogs, and buffaloes. Correlations were assessed by the Chi-square or Fisher's exact tests.

RESULTS

Mastitis (45.1%), abscesses (18.0%), pneumonia (11.1%), and lymphadenitis (9.0%) were the most common clinical manifestations. In addition, the organism was also isolated from other miscellaneous clinical specimens from cases of septicemia, encephalitis, pyometra, prostatitis, orchitis, seminal vesiculitis, pericarditis, and omphalitis. No statistical association was observed between T. pyogenes infections and age, gender, or season across the study. The most effective drugs against the pathogen were florfenicol (99.1%), cefoperazone (96.0%), cephalexin (95.0%), and ceftiofur (94.8%). High resistance rates were observed against trimethoprim-sulfamethoxazole (49.3%), followed by norfloxacin (10.9%) and tetracycline (9.2%).

CONCLUSIONS

This study highlights the diversity of clinical manifestations and the opportunistic behavior of T. pyogenes infections in domestic animals, with predominance of mastitis, abscesses, pneumonia, and lymphadenitis. It also reinforces the importance of knowing the susceptibility profile before initiating therapy, to improve antimicrobial therapy approaches.

Identification of pathogens and virulence profile of Rhodococcus equi and Escherichia coli strains obtained from sand of parks

The identification of pathogens of viral (Rotavirus, Coronavirus), parasitic (Toxocara spp.) and bacterial (Escherichia coli, Salmonella spp., Rhodococcus equi) origin shed in feces, and the virulence profile of R. equi and E. coli isolates were investigated in 200 samples of sand obtained from 40 parks, located in central region of state of Sao Paulo, Brazil, using different diagnostic methods. From 200 samples analyzed, 23 (11.5%) strains of R. equi were isolated. None of the R. equi isolates showed a virulent (vapA gene) or intermediately virulent (vapB gene) profiles. Sixty-three (31.5%) strains of E. coli were identified. The following genes encoding virulence factors were identified in E. coli: eae, bfp, saa, iucD, papGI, sfa and hly. Phylogenetic classification showed that 63 E. coli isolates belonged to groups B1 (52.4%), A (25.4%) and B2 (22.2%). No E. coli serotype O157:H7 was identified. Eggs of Toxocara sp. were found in three parks and genetic material of bovine Coronavirus was identified in one sample of one park. No Salmonella spp. and Rotavirus isolates were identified in the samples of sand. The presence of R. equi, Toxocara sp, bovine Coronavirus and virulent E. coli isolates in the environment of parks indicates that the sanitary conditions of the sand should be improved in order to reduce the risks of fecal transmission of pathogens of zoonotic potential to humans in these places.

Molecular identification and thermoresistance to boiling of Nocardia farcinica and Nocardia cyriacigeorgica from bovine bulk tank milk

Two strains of Nocardia spp. were isolated from bovine milk of two individual bulk tank. Molecular identification classified the strains as Nocardia farcinica and Nocardia cyriacigeorgica. The thermorresistance to boiling of the isolates was carried out and was observed bacterial growth after boiling. Our findings indicate the potential risk of pathogen transmission to humans through contaminated milk with Nocardia spp.