Common Veterinary Pathogens Research Articles

Frequency of respiratory pathogens and SARS-CoV-2 in canine and feline samples submitted for respiratory testing in early 2020.

ObjectivesThe emergence of the 2019 novel coronavirus (SARS‐CoV‐2) has necessitated evaluation of the potential for SARS‐CoV‐2 infection in dogs and cats. Using a large data set, we evaluated the frequency of SARS‐CoV‐2 and other respiratory pathogens in samples submitted for respiratory testing from mid‐February to mid‐April 2020.Materials and MethodsA SARS‐CoV‐2 real‐time PCR was developed and validated. A subset of canine and feline samples submitted for respiratory pathogen panel testing to reference laboratories in Asia, Europe, and North America were also tested for SARS‐CoV‐2. The frequency of respiratory pathogens was compared for the February–April period of 2020 and 2019.ResultsSamples from 4616 patients were included in the study and 44% of canine and 69% of feline samples were PCR positive with Mycoplasma cynos and Bordetella bronchiseptica and Mycoplasma felis and feline calicivirus, respectively. No SARS‐CoV‐2 infections were identified. Positive results for respiratory samples were similar between years.Clinical SignificanceThe data in this study suggest that during the emergence of the SARS‐CoV‐2 pandemic in early 2020, respiratory diseases in tested pet cats and dogs were caused by common veterinary pathogens and that SARS‐CoV‐2 infections in dogs and cats are rare.

Potent, specific MEPicides for treatment of zoonotic staphylococci.

Coagulase-positive staphylococci, which frequently colonize the mucosal surfaces of animals, also cause a spectrum of opportunistic infections including skin and soft tissue infections, urinary tract infections, pneumonia, and bacteremia. However, recent advances in bacterial identification have revealed that these common veterinary pathogens are in fact zoonoses that cause serious infections in human patients. The global spread of multidrug-resistant zoonotic staphylococci, in particular the emergence of methicillin-resistant organisms, is now a serious threat to both animal and human welfare. Accordingly, new therapeutic targets that can be exploited to combat staphylococcal infections are urgently needed. Enzymes of the methylerythritol phosphate pathway (MEP) of isoprenoid biosynthesis represent potential targets for treating zoonotic staphylococci. Here we demonstrate that fosmidomycin (FSM) inhibits the first step of the isoprenoid biosynthetic pathway catalyzed by deoxyxylulose phosphate reductoisomerase (DXR) in staphylococci. In addition, we have both enzymatically and structurally determined the mechanism by which FSM elicits its effect. Using a forward genetic screen, the glycerol-3-phosphate transporter GlpT that facilitates FSM uptake was identified in two zoonotic staphylococci, Staphylococcus schleiferi and Staphylococcus pseudintermedius. A series of lipophilic ester prodrugs (termed MEPicides) structurally related to FSM were synthesized, and data indicate that the presence of the prodrug moiety not only substantially increased potency of the inhibitors against staphylococci but also bypassed the need for GlpT-mediated cellular transport. Collectively, our data indicate that the prodrug MEPicides selectively and robustly inhibit DXR in zoonotic staphylococci, and further, that DXR represents a promising, druggable target for future development.

Investigation of the effects of an ultraviolet germicidal irradiation system on concentrations of aerosolized surrogates for common veterinary pathogens.

To determine whether exposure to UV germicidal irradiation (UVGI) reduces concentrations of viable aerosolized microorganisms (attenuated strains of common veterinary pathogens) in a simulated heating, ventilation, and air conditioning (HVAC) system. 42 air samples seeded with bacteriophage MS2 or attenuated strains of Bordetella bronchiseptica, feline calicivirus, feline herpesvirus-1, canine parvovirus, or canine distemper virus (6/microorganism) or with no microorganisms added (6). A simulated HVAC unit was built that included a nebulizer to aerosolize microorganisms suspended in phosphate-buffered water, a fan to produce airflow, 2 UVGI bulb systems, and an impinger for air sampling. Ten-minute trials (3 with UVGI, 3 without UVGI, and 1 negative control) were conducted for each microorganism. Impingers collected microorganisms into phosphate-buffered water for subsequent quantification with culture-based assays. Results for samples yielding no target microorganisms were recorded as the assay's lower limit of detection. Statistical analysis was not performed. The UVGI treatment resulted in subjectively lower concentrations of viable MS2, B bronchiseptica, and canine distemper virus (arithmetic mean ± SD log10 microorganism reduction, 2.57 ± 0.47, ≥ 3.45 ± 0.24, and ≥ 1.50 ± 0.25, respectively) collected from air. Feline herpesvirus-1 was detected in only 1 sample without and no samples with UVGI treatment. Feline calicivirus and canine parvovirus were not detectable in any collected samples. Results for some surrogates of veterinary pathogens suggested a potential benefit to supplementing manual disinfection practices with UVGI-based air cleaning systems in animal care environments. Further research is needed to investigate the utility of UVGI in operating HVAC systems.

Antimicrobial labelling in Australia: a threat to antimicrobial stewardship?

Antimicrobial resistance is a public health emergency, placing veterinary antimicrobial use under growing scrutiny. Antimicrobial stewardship, through appropriate use of antimicrobials, is a response to this threat. The need for antimicrobial stewardship in Australian veterinary practices has had limited investigation. A 2016 survey undertaken to investigate antimicrobial usage patterns by Australian veterinarians found that antimicrobial dose rates were varied and often inappropriate. Doses of procaine penicillin in horses and cattle were often low, with 68% and 90% of respondents, respectively, reporting doses that were unlikely to result in plasma concentrations above minimum inhibitory concentrations for common equine and bovine pathogens. Frequency of penicillin administration was also often inappropriate. Gentamicin doses in horses were largely appropriate (89% of dose rates appropriate), but 9% of respondents reported twice daily dosing. Amoxycillin and amoxycillin-clavulanate were administered at the appropriate doses, or above, to dogs and cats by 54% and 70% of respondents, respectively. Here, we explore the potential reasons for inappropriate antimicrobial dose regimens and report that antimicrobial labels often recommend incorrect dose rates and thus may be contributing to poor prescribing practices. Changes to legislation are needed to ensure that antimicrobial drug labels are regularly updated to reflect the dose needed to effectively and safely treat common veterinary pathogens. This will be especially true if changes in legislation restrict antimicrobial use by veterinarians to the uses and doses specified on the label, thus hampering the current momentum towards improved antimicrobial stewardship.

Rapid identification of the animal pathogens Streptococcus uberis and Arcanobacterium pyogenes by fluorescence in situ hybridization (FISH)

Fluorescence in situ hybridization (FISH) has been reported to be an easy and rapid identification method for many human pathogens, but applications for common veterinary pathogens are lacking. Gene probes for FISH of the animal pathogens Streptococcus uberis and Arcanobacterium pyogenes were designed to provide probes for a specific identification of these bacteria from cultures. Specific FISH probes for these species have so far not been published. Both probes recognized all isolates of the target species correctly. With the S. uberis probe SUB 196 no false-positive results were obtained for reference strains as well as for clinical isolates. Probe APYO 183 for A. pyogenes produced false-positive reactions with so far rarely described Arcanobacterium species from animals at standard hybridization conditions. In order to avoid any incorrect classifications of microorganisms as A. pyogenes, two non-labelled competitor probes were designed and successfully evaluated.

Proteomic Analyses of Host and Pathogen Responses during Bovine Mastitis

The pursuit of biomarkers for use as clinical screening tools, measures for early detection, disease monitoring, and as a means for assessing therapeutic responses has steadily evolved in human and veterinary medicine over the past two decades. Concurrently, advances in mass spectrometry have markedly expanded proteomic capabilities for biomarker discovery. While initial mass spectrometric biomarker discovery endeavors focused primarily on the detection of modulated proteins in human tissues and fluids, recent efforts have shifted to include proteomic analyses of biological samples from food animal species. Mastitis continues to garner attention in veterinary research due mainly to affiliated financial losses and food safety concerns over antimicrobial use, but also because there are only a limited number of efficacious mastitis treatment options. Accordingly, comparative proteomic analyses of bovine milk have emerged in recent years. Efforts to prevent agricultural-related food-borne illness have likewise fueled an interest in the proteomic evaluation of several prominent strains of bacteria, including common mastitis pathogens. The interest in establishing biomarkers of the host and pathogen responses during bovine mastitis stems largely from the need to better characterize mechanisms of the disease, to identify reliable biomarkers for use as measures of early detection and drug efficacy, and to uncover potentially novel targets for the development of alternative therapeutics. The following review focuses primarily on comparative proteomic analyses conducted on healthy versus mastitic bovine milk. However, a comparison of the host defense proteome of human and bovine milk and the proteomic analysis of common veterinary pathogens are likewise introduced.

Bordetella bronchisepticaPneumonia in an Extremely-Low-Birth-Weight Neonate

Bordetella bronchiseptica, a gram-negative coccobacillus, is a common veterinary pathogen. In both domestic and wild animals, this bacterium causes respiratory infections including infectious tracheobronchitis in dogs and atrophic rhinitis in swine. Human infections are rare and have been documented in immunocompromised hosts. Here, we describe an extremely-low-birth-weight infant with B. bronchiseptica pneumonia. This is the first report that describes the microorganism's responsibility in causing nosocomial infection in a preterm neonate. He recovered uneventfully after a course of meropenem. It is possible that the bacteria colonize the respiratory tracts of our health care workers or parents who may have had contact with pets and then transmitted the bacterium to our patient. Follow-up until 21 months of age showed normal growth and development. He did not suffer from any significant residual respiratory disease.

Relapsing Peritonitis Caused by Bordetella bronchiseptica in Continuous Ambulatory Peritoneal Dialysis Patient: A Case Report

Bordetella (B) bronchiseptica is a common veterinary pathogen, but has rarely been implicated in human infections. Most patients with B. bronchiseptica infections are compromised clinically such as in patients with a malignancy, AIDS, malnutrition, or chronic renal failure. We experienced a case of relapsing peritonitis caused by B. bronchiseptica associated with continuous ambulatory peritoneal dialysis (CAPD). A 56-yr-old male, treated with CAPD due to end stage renal disease (ESRD), was admitted with complaints of abdominal pain and a turbid peritoneal dialysate. The culture of peritoneal dialysate identified B. bronchiseptica. The patient was treated with a combination of intraperitoneal antibiotics. There were two further episodes of relapsing peritonitis, although the organism was sensitive to the used antibiotics. Finally, the indwelling CAPD catheter was removed and the patient was started on hemodialysis. This is the first report of a B. bronchiseptica human infection in the Korean literature.