Veterinary Diagnostic Laboratory Research Articles

Prevalence, risk factors, and hematologic changes in dogs from Baja California with presence of Ehrlichia spp., and coinfection with Anaplasma spp.

Ehrlichia and Anaplasma are obligate intracellular, gram-negative bacteria with tropism for hematopoietic cells, especially leukocytes and platelets. There are several Ehrlichia species that infect dogs. Ehrlichia canis is transmitted by Rhipicephalus sanguineus and replicates within monocytes and macrophages, leading to canine monocytic ehrlichiosis, a disease of worldwide distribution. The clinical signs are varied and non-specific. Anaplasma has two species that infect dogs, Anaplasma phagocytophilum and Anaplasma platys, the second also transmitted by Rhipicephalus sanguineus. This study aimed to evaluate the epidemiology and hematologic changes associated with the presence of Ehrlichia spp. and Anaplasma spp. coinfection in dogs from Baja California. Complete hematological analysis, examination of buffy coat smears, and ELISA tests were performed on blood samples from three veterinary diagnostic laboratories from Mexicali and Tijuana cities in Baja California, Mexico. A total of 5,469 dog samples were analyzed. The overall prevalence of Ehrlichia spp., was 4.79%, with a distribution of 6.3% in Mexicali (OR: 2.39 CI: 1.69-3.17) and 2.5% in Tijuana. The peak of infection was found in September. Contact with other dogs and tick infestation were the risk factors associated with infection (P < 0.05). There was 96% co-infection only in Tijuana and 0% in Mexicali. Anemia, thrombocytopenia, and hyperproteinemia are associated with Ehrlichia spp., and Ehrlichia/Anaplasma infection. In view of the foregoing, we have to maintain epidemiologic vigilance, as well as look further into the ticks present in the state and the possibility of transmission of unusual pathogens.

Prevalence, risk factors, and hematologic changes in dogs from Baja California with presence of Ehrlichia spp., and coinfection with Anaplasma spp.

Ehrlichia and Anaplasma are obligate intracellular, gram-negative bacteria with tropism for hematopoietic cells, especially leukocytes and platelets. There are several Ehrlichia species that infect dogs. Ehrlichia canis is transmitted by Rhipicephalus sanguineus and replicates within monocytes and macrophages, leading to canine monocytic ehrlichiosis, a disease of worldwide distribution. The clinical signs are varied and non-specific. Anaplasma has two species that infect dogs, Anaplasma phagocytophilum and Anaplasma platys, the second also transmitted by Rhipicephalus sanguineus. This study aimed to evaluate the epidemiology and hematologic changes associated with the presence of Ehrlichia spp. and Anaplasma spp. coinfection in dogs from Baja California. Complete hematological analysis, examination of buffy coat smears, and ELISA tests were performed on blood samples from three veterinary diagnostic laboratories from Mexicali and Tijuana cities in Baja California, Mexico. A total of 5,469 dog samples were analyzed. The overall prevalence of Ehrlichia spp., was 4.79%, with a distribution of 6.3% in Mexicali (OR: 2.39 CI: 1.69-3.17) and 2.5% in Tijuana. The peak of infection was found in September. Contact with other dogs and tick infestation were the risk factors associated with infection (P < 0.05). There was 96% co-infection only in Tijuana and 0% in Mexicali. Anemia, thrombocytopenia, and hyperproteinemia are associated with Ehrlichia spp., and Ehrlichia/Anaplasma infection. In view of the foregoing, we have to maintain epidemiologic vigilance, as well as look further into the ticks present in the state and the possibility of transmission of unusual pathogens.

Prevalence and molecular epidemiology of carbapenemase-producing Enterobacterales isolated from dog and cat faeces submitted to veterinary laboratories in the USA.

To estimate the prevalence of carbapenemase-producing Enterobacterales (CPE) carriage among pets using faecal specimens submitted to veterinary diagnostic laboratories throughout the US. A secondary aim was to employ whole-genome sequencing (WGS) to characterize isolates of CPE from companion animals and compare them to publicly available CPE genomes. To estimate the prevalence of CPE in companion animals in the USA, a multicenter surveillance study including 8 different veterinary diagnostic laboratories from across the USA was conducted. Briefly, remnant faecal specimens from dogs and cats were screened using two selective agar plates (CHROMID Carba and MacConkey with 1 mg/L cefotaxime and 0.125 mg/L meropenem) and presumptive CPE isolates screened by the modified carbapenemase inactivation method for carbapenemase production. A total of 2393 specimens were screened and yielded 196 isolates for carbapenemase screening. A total of 5 isolates from 4 dogs and 1 cat at 3 different veterinary diagnostic laboratories were confirmed to produce a carbapenemase (0.21%). Whole-genome sequencing (WGS) revealed two E. coli (ST167) isolates that both produced an NDM-5 carbapenemase, two Enterobacter hormaechei (ST171) isolates that produced an NDM-5 carbapenemase and a KPC-4 carbapenemase respectively and one Klebsiella oxytoca (ST199) that produced an Oxa-48-type carbapenemase. Both E. coli isolates were found to be within at least 22 SNPs of previously characterized canine and human CPE isolates. This study demonstrates that the prevalence of CPE among companion animals is relatively low (0.21%) but that given the genetic relatedness of animal isolates to human isolates, additional surveillance is needed.

Retrospective study of laboratory-based surveillance of rabies in wild and domestic animals in the southern United States, 2010-2021.

We performed a retrospective study of all case submissions for the rabies virus (RABV) direct fluorescent antibody test (DFAT) requested of the Tifton Veterinary Diagnostic and Investigational Laboratory (Tifton, GA, USA) between July 2010 and June 2021. Submitted were 792 samples from 23 animal species from 89 counties in Georgia, and 4 neighboring counties in Florida, 1 in South Carolina, and 1 in Alabama. In 13 (1.6%) cases, the DFAT result was inconclusive; 779 (98.4%) cases had a conclusive (positive or negative) test result. Of these 779 cases, 79 (10.1%) tested positive across 10 species. The remaining 700 (89.9%) cases were negative. The main reason for submission for RABV testing was human exposure to a potentially rabid animal in 414 (52.3%) cases. Among the 79 positive cases, 74 (93.7%) involved wildlife; raccoons (51 cases; 68.9%) were the primary host confirmed with RABV infection, followed by skunk and fox (8 cases each; 10.8%), bobcat (5 cases; 6.8%), and bats (2 cases; 2.7%). Only 5 domestic animals (6.3% of the positive cases) tested positive during our study period; one from each of the bovine, canine, caprine, equine, and feline species. Hence, the sylvatic cycle plays the predominant role in circulating RABV infection in our study area.

The use of telepathology in veterinary medicine: a scoping review.

Telepathology, as a subset of teleconsulting, is pathology interpretation performed at a distance. Telepathology is not a new phenomenon, but since ~2015, significant advances in information technology and telecommunications coupled with the pandemic have led to unprecedented sophistication, accessibility, and use of telepathology in human and veterinary medicine. Furthermore, telepathology can connect veterinary practices to distant laboratories and provide support for underserved animals and communities. Through our scoping review, we provide an overview of how telepathology is being used in veterinary medicine, identify gaps in the literature, and highlight future areas of research and service development. We searched MEDLINE, CAB Abstracts, and the gray literature, and included all relevant literature. Despite the widespread use of digital microscopy in large veterinary diagnostic laboratories, we identified a paucity of literature describing the use of telepathology in veterinary medicine, with a significant gap in studies addressing the validation of whole-slide imaging for primary diagnosis. Underutilization of telepathology to support postmortem examinations conducted in the field was also identified, which indicates a potential area for service development. The use of telepathology is increasing in veterinary medicine, and pathologists must keep pace with the changing technology, ensure the validation of innovative technologies, and identify novel uses to advance the profession.

Multi-drug resistant Salmonella Dublin cultured from cryopreserved Holstein semen

Salmonella enterica subspecies enterica serotype Dublin, com­monly referred to as Salmonella Dublin, has emerged as one of the most isolated serotypes of Salmonella in U.S. cattle. A highly multi-drug resistant isolate of Salmonella Dublin was cultured at the Wisconsin Veterinary Diagnostic Laboratory (WVDL) from both the raw and cryopreserved, extended semen of a 17-month-old clinically healthy Holstein bull. The objective of this study was to use antemortem and postmortem diagnos­tic testing to evaluate the systemic health of the bull and deter­mine where he was harboring the Salmonella Dublin infection.

100 Evaluating the effect of liver copper concentration on vaccine response in lightweight dairy-beef steers

Abstract Dairy-beef crossbred calves often face greater copper (Cu) exposure than native beef calves, which may impact their response to vaccines. To investigate this, 28 weaned dairy-beef steers (90.25 ± 1.28 kg; ~8 wk old) were enrolled in a study to determine the effect of Cu status on the antibody response to vaccine. Steers were stratified by body weight (BW) and assigned to one of two dietary treatments: low Cu (no supplemental Cu) and high Cu (supplementing 20 mg Cu/kg DM). Steers were housed in pens of six to eight animals for 82 d before d 0 of the vaccination period to create distinct liver Cu groupings. Seven days before initial vaccine dose, liver biopsies were collected, and steers were grouped into low (n = 13) and high (n = 15) Cu treatments. Liver Cu for low Cu averaged 291 ± 24 mg/kg DM (range 240 to 376 mg/kg DM) and for high Cu averaged 665 ± 23 mg Cu/kg liver DM (range 519 to 893 mg/kg DM). All calves were vaccinated on d 0 and boostered 21 d later with Bovilis Vista 5 SQ (Merck Animal Health, Rahway, NJ) and an ovalbumin vaccine. Blood and BW were collected on these days and again on d 49 to end the study. Serum antibody titers for BRSV, BHV1, BVDV1, and BVDV2 were analyzed by the Iowa State University Veterinary Diagnostic Laboratory (Ames, IA). Response to ovalbumin vaccination was determined using an ELISA. Plasma Cu concentrations were determined on d 0, 21, and 49 via ICP-OES. Ovalbumin antibodies were determined by calculating the ratio of each sample to a positive control. Titers, ovalbumin response, and plasma Cu data from d 0, 21, and 49 were analyzed using the Mixed procedure of SAS 9.4 (Cary, NC) with the fixed effect of Cu treatment and day as repeated. Plasma Cu decreased across days (P = 0.0008). Given both treatments had adequate liver Cu, it is unsurprising plasma Cu did not differ by treatment (P = 0.2; 1.02 and 1.07 mg Cu/L for low and high Cu, respectively). Antibodies for BRSV, BHV1, and BVDV2 increased across days (P < 0.0001), but there were no differences by treatment (P ≥ 0.12). Ovalbumin antibodies were affected by treatment by day (P = 0.04), where high Cu had greater response to ovalbumin than low Cu on d 21, but by d 49 ovalbumin antibodies were similar between Cu treatments. These results suggest excessive liver Cu concentration may not affect response to vaccination in dairy-beef steers; however, more research is needed to determine the effects of increased liver Cu concentration on oxidative stress and immune system function.

PSI-4 Evaluation of chemical mitigants when soybean meal was inoculated with porcine epidemic diarrhea virus, porcine reproductive and respiratory virus, and Seneca Valley virus 1

Abstract Chemical mitigants have been found to decrease virus concentrations in feed and ingredient matrices. Continued research is needed to identify the appropriate inclusion levels and application time for different viruses in these matrices. Therefore, the objective was to evaluate different inclusion levels of two different chemical mitigants when applied either before or after inoculation of porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV) and Seneca Valley virus 1 (SVV1) to soybean meal. The experiment was designed in a 2×2×2 factorial with two chemical mitigants, a formaldehyde-based product (Termin-8, Anitox Corp. Lawrenceville, GA) and a product containing Synergistic blend of phytochemicals and carboxylic acids (Finio, Anitox Corp. Lawrenceville, GA), two applications times, before virus inoculation (prevention) and after virus inoculation (mitigation), and either a low or high inclusion level (Termin-8: 2 or 3 kg/MT; Finio: 1.75 or 2.75 kg/MT). On d 1, samples of the respective matrices were weighed in 50 g aliquots and added to 500 mL bottles. Chemical mitigants were applied to the prevention samples at their respective inclusion levels and 50 µL each of 1×107 TCID50/mL PEDV, 1×108 TCID50/mL PRRSV, and 1×108 TCID50/mL SVV1 were added to the mitigation samples. All bottles were shaken and allowed to sit at room temperature for 24 h. On d 2, virus was added to the prevention samples and chemical mitigants were added to the mitigation bottles, samples incubated at room temperature for 1 h before 200 mL of phosphate buffer solution was added, and bottles incubated at 4°C for 18 h. After incubation, liquid from the samples was centrifuged and the supernatant analyzed via triplex PCR at Kansas State University Veterinary Diagnostic Laboratory. Cycle threshold and proportion PCR positive were analyzed using SAS GLIMMIX v 9.4 (SAS, Inc., Cary, NC) with each virus and matrix combination analyzed individually. A chemical mitigant×application time×inclusion level interaction was not observed (P > 0.05) for any virus. A chemical mitigant×application time interaction was observed (P < 0.05) in all three viruses, where less viral RNA was detected (P < 0.05) when either Termin-8 or Finio were applied after inoculation (mitigation) than when applied prior to inoculation or to the positive controls. An application time×inclusion level interaction was noticed (P < 0.05) for SVV1 and PEDV in soybean meal. Chemical mitigants applied at either the low or high inclusion level after inoculation (mitigation) had less detectable RNA (P < 0.05) than their prevention counterparts. Overall, Termin-8 and Finio can reduce detectable RNA immediately in contaminated soybean meal, with ongoing research evaluating the effect of extended contact times between the mitigants and soybean meal.

212 Growth and behavior of Yorkshire gilts exhibiting physiological resilience to weaning stress

Abstract Weaning is an acute early-life stressor and therefore, an excellent model for examining lasting impacts of stress resilience. Our objective was to identify gilts exhibiting physiological resilience or vulnerability to weaning stress and characterize long-term impact on growth and behavior. Purebred Yorkshire litters born to multiparous sows from a single farrowing group were used. At weaning (26 ± 1 d of age), blood samples were collected from all gilt piglets of 13 litters (n = 101) at -1 d, 0 d, and +4 d pre- and post-weaning. Serum cortisol concentrations were quantified by the Michigan State University Veterinary Diagnostic Laboratory. For each litter, serum cortisol was used to identify the gilt most capable of returning to baseline concentrations by +4 d as stress resilient (SR, n = 13) and the gilt least capable as stress vulnerable (SV, n = 13). Skin lesions were recorded at -1 d, +1 d, and +4 d at weaning and when gilts were mixed into grow-finish cohorts. Body weights were recorded at birth, 4 wk, 8 wk, and 12 wk and used to calculate average daily gain (ADG) for the farrowing, nursery, and early grow-finish stages. To assess behavior, focal gilts underwent a social dyad test in a novel arena at 7 wk, a handling test at 8 wk, and novel object test at 12 wk. We observed no differences in skin lesions at weaning, but at 8 wk SR gilts had significantly more rear lesions -1 d pre-mixing (P = 0.031) and middle lesions 4 d post-mixing (P = 0.049). No differences in body weight or ADG were observed at any stage. We did not observe differences between SR and SV pigs during the social dyad or handling tests. During the novel object test, SR gilts exhibited a tendency towards increased activity as demonstrated by a greater number of total zone crosses, 1 m line crosses, and 0.5 m line crosses (P = 0.062, 0.091, and 0.103, respectively). In conclusion, we found gilts resilient to weaning stress were involved in more agonistic behavior at mixing and exhibited increased activity levels in a novel situation. The absence of growth differences supports the potential to select for resilience without negatively impacting growth performance, and the observed behavioral differences could suggest implications for ease of handling and adaptability if females are retained for breeding.

198 Evaluation of zinc source and concentration on growth performance of nursery swine

Abstract Trace minerals (TM) supplementation in swine diets can negatively interact with other nutrients. Zinc (Zn) and copper (Cu) mutually inhibit their intestinal absorption; thus, limiting their bioavailability. Recent peer-reviewed work has suggested that nursery pigs fed a diet supplemented with increased Zn experienced impaired Cu metabolism, negatively impacting growth performance. However, it has been demonstrated that mitigation of antagonisms might be possible with the use of organic TM supplemented at decreased concentrations. To validate these findings, a total of 2,629 pigs [initial body weight (BW) = 6.2 kg] were used in a 37-d experiment. Pens of 36 pigs were randomly allotted to 1 of 8 dietary treatments with 9 replications per treatment. Dietary treatments were formulated to contain 1 of 4 Zn sources: Zn Sulfate, Zn Hydroxychloride A (Intellibond Zn [Micronutrients Inc., Indianapolis, IN), Zn Hydroxychloride B [Zn Hydroxychloride (Alltech, Inc., Nicholasville, KY)] or Organic Zn [Bioplex Zn (Alltech, Inc)] at 1 of 2 concentrations: 125 or 250 ppm. The concentrations utilized for Organic Zn treatment were 62.5 or 125 ppm per published recommendations. Experimental diets were fed in two phases: phase 1 from d 0 to 21 and phase 2 from d 22 to 37. Added Cu in both dietary phases was 10 ppm. At d 37, serum and liver samples (data not showed) were collected from 1 barrow per pen and submitted to Michigan State University Veterinary Diagnostic Laboratory to determine Zn and Cu concentration. No significant source × concentration interactions were observed for growth performance in this study. From d 0 to 37, pigs fed the greatest Zn concentration had less (P = 0.040) average daily feed intake (ADFI) and marginally decreased (P = 0.060) average daily gain (ADG), despite Zn source (Table 1). In addition, a marginal improvement (P = 0.070) in gain to feed ratio (G:F) was observed in pigs fed diets containing Organic Zn, regardless of concentration. For mineral concentrations in serum, there was a marginally significant source × concentration interaction (P = 0.078), where pigs fed diets with 125 ppm of Zn Hydroxychloride B had one of the greatest Zn concentrations, yet it was drastically reduced when pigs were fed diets with 250 ppm. Furthermore, Cu concentration in serum was decreased (P = 0.045) in pigs fed the greatest concentration of Zn, despite source. In conclusion, these results suggest that greater dietary Zn concentration impaired Cu absorption, reduced feed intake, and marginally decreased growth. Organic Zn, included at 50% reduced concentrations, marginally improved feed efficiency.

A Retrospective Descriptive Study of Staphylococcus Species Isolated from Canine Specimens Submitted to a Diagnostic Laboratory in South Africa, 2012-2017.

There is a scarcity of published studies on the occurrence of Staphylococcus spp. Among dogs in South Africa. The objective of the study was to characterise the Staphylococcus spp. Isolated from dog samples submitted to a veterinary diagnostic laboratory in South Africa in terms of time, place, and person. This study utilised a dataset of 1627 positive Staphylococcus isolates obtained from a veterinary diagnostic laboratory in South Africa from 2012 to 2017. Out of the 1627 confirmed isolates, 10 different species of Staphylococcus were identified. Among these, 92.0% were classified as coagulase-positive staphylococci (CoPS), 6.0% were coagulase-negative staphylococci (CoNS), and 3.0% were coagulase-variable. Male dogs contributed just over half (53.2%) of the Staphylococcus isolates, while female dogs contributed the remaining 46.8%. The largest proportion of isolates (23.2%) were obtained from dogs aged ≥ 9 years, with the highest number of isolates originating from KwaZulu-Natal Province (45.0%) and the least from Northern Cape Province (0.1%). Out of the total samples included in the records, the majority (46.0%) were skin specimens. The number of Staphylococcus isolates recorded showed limited variation between the seasons (24.3% in autumn, 26.3% in winter, 26.0% in spring, and 24.0% in summer). This study highlighted the diversity of Staphylococcus spp. isolated from dogs, and the burden of staphylococcal carriage among dogs in South Africa. Further research is required to examine the factors that contribute to the observed discrepancies in the proportions of Staphylococcus spp. between the provinces.

African Swine Fever Diagnosis in Africa: Challenges and Opportunities.

The global spread of African swine fever (ASF) in recent decades has led to the need for technological advances in sampling and diagnostic techniques. The impetus for these has been the need to enable sampling by lay persons and to obtain at least a preliminary diagnosis in the field for early control measures to be put in place before final laboratory confirmation. In rural Africa, rapid diagnosis is hampered by challenges that include lack of infrastructure as well as human and financial resources. Lack of animal health personnel, access to affordable means to transport field samples to a laboratory, and lack of laboratories with the capacity to make the diagnosis result in severe under-reporting of ASF, especially in endemic areas. This review summarizes the challenges identified in gap analyses relevant to low- and middle-income countries, with a focus on Africa, and explore the opportunities provided by recent research to improve field diagnosis and quality of diagnostic samples used. Sampling techniques include invasive sampling techniques requiring trained personnel and non-invasive sampling requiring minimal training, sampling of decomposed carcass material, and preservation of samples in situations where cold chain maintenance cannot be guaranteed. Availability and efficacy of point-of-care (POC) tests for ASF has improved considerably in recent years and their application, as well as advantages and limitations, are discussed. The adequacy of existing laboratory diagnostic capacity is evaluated and opportunities for networking amongst reference and other laboratories offering diagnostic services are discussed. Maintaining laboratory diagnostic efficiency in the absence of samples during periods of quiescence is another issue that requires attention, and the role of improved laboratory networking is emphasized. Early diagnosis of ASF is key to managing the disease spread. Therefore, the establishment of the Africa Chapter of the Global African Swine Fever Research Alliance (GARA) increases opportunities for collaboration and networking among the veterinary diagnostic laboratories in the region.

Carbapenemase-producing Enterobacterales strains causing infections in companion animals-Portugal.

This is the first study on the prevalence of carbapenemase-producing Enterobacterales (CPE) clinical strains from companion animals in Portugal. Despite the generally low prevalence of CPE in companion animals, it is imperative for veterinary diagnostic laboratories to employ diagnostic methods for carbapenemase detection. The resemblance found in the mobile genetic elements transporting carbapenemase genes between veterinary medicine and human medicine implies a potential circulation within a One Health framework.

Preliminary study on buffy coat smear and molecular detection of microfilaria in domestic chickens (Gallus gallus domesticus) raised in Southern Thailand

Background and Aim: Filarial nematode typically produces a larval stage (microfilariae) in the bloodstream of vertebrate hosts, where microfilariae reside in the blood or subcutaneous tissues. Filarial nematodes cause human diseases, such as river blindness and elephantiasis, which are widely studied. However, in avian species, they are overlooked because they are nonpathogenic. In Thailand, microfilaria can be found in wild birds and domestic chickens. Recently, an increase in the number of blood samples submitted to veterinary diagnostic laboratories may have increased the number of microfilariae. Therefore, knowledge about filarial species and reliable detection methods are important. Therefore, this study aimed to investigate the efficacy of buffy coat smear and polymerase chain reaction (PCR)-based methods for the detection of microfilaria in domestic chickens. In addition, parasites were identified using the sequence of the cytochrome c oxidase subunit 1 (COX1) gene. Materials and Methods: Giemsa-stained buffy coat smears from a previous study were reanalyzed. These available buffy coat smears were prepared from 55 domestic chickens raised as backyard free-ranging in Southern Thailand. Fifty-seven frozen genomic DNA extracted from chicken blood were used to detect the presence of the COX1 gene in Onchocercidae nematodes. The nested PCR protocol for amplification of the OnchoCOI_ R2-OnchoCOI_ R2 fragment of the COX1 gene was applied from a previous report. Sequences of COX1 were analyzed to identify Onchocercidae nematodes and if they were single or mixed infections. We constructed Bayesian phylogenetics to identify parasites and assessment of the relationship between filarial nematodes in avian species and other vertebrate hosts. Results: Buffy coat smears from 15 samples revealed microfilaria. Of these 15 samples, only eight were positive for COX1 nested-PCR amplification. The other two buffy coat-negative samples were also positive for nested-PCR. Sequencing of these 11 nested PCR-positive samples revealed that almost all of them were Onchocercidae nematodes. Bayesian phylogenetic analysis showed that chicken Onchocercidae spp. were grouped with other avian filarial nematodes. However, all chickens Onchocercidae spp. showed a double peak in the sequencing chromatogram, indicating mixed filarial infection (species or haplotypes). Therefore, no chicken Onchocercidae sequence was deposited on National Center for Biotechnology Information, GenBank. Conclusion: Giemsa-stained buffy coat smear was a reliable method for the detection of chicken microfilaria in routine veterinary diagnostic laboratories. Development of a new PCR-based method is necessary. This method may provide greater sensitivity and specificity of detection. In addition, the PCR method allowed us to access the genetic characteristics of nematodes, which helped us maximize our knowledge of nematodes. Further investigations, such as the pathogenicity of filarial nematodes in chickens and their potential vectors, are required. Keywords: Buffy coat smear, Chickens, Cytochrome c oxidase I, Microfilaria, Nested-polymerase chain reaction.

Embolic necrosuppurative pneumonia in domestic cats induced by a novel Neisseria species.

Three cats, aged 2 to 11 years, presented to the University of Minnesota Veterinary Diagnostic Laboratory over a 3-year period following euthanasia or death due to respiratory distress. Thoracic radiographs revealed nodular, soft tissue opacities throughout the lung fields in all cases. On postmortem examination, approximately 60% to 80% of the lung parenchyma were expanded by multifocal to coalescing, well-demarcated, beige, semi-firm nodules. Histologically, large numbers of neutrophils, fewer macrophages, fibrin, and cellular and karyorrhectic debris effaced the pulmonary parenchyma. The inflammatory foci contained aggregates of gram-negative cocci. 16s rRNA Sanger sequencing and whole-genome sequencing identified the bacteria isolated from the lung of all cats under aerobic conditions as a novel Neisseria spp. Based on whole-genome sequence analysis, all 3 sequences shared 92.71% and 92.67% average nucleotide identity with closely related Neisseria animaloris NZ LR134440T and Neisseria animaloris GCA 002108605T, respectively. The in silico DNA-DNA hybridization identity compared to our isolates was 46.6% and 33.8% with strain DSM Neisseria zoodegmatis 21642 and strain DSM 21643, respectively. All 3 sequences have less than 95% average nucleotide identity and less than 70% DNA-DNA hybridization identity, suggesting that the 3 isolates are a novel species of the genus Neisseria. Infection with Neisseria spp. induces an embolic pneumonia in cats that radiographically and pathologically resembles a metastatic neoplastic process and should be considered among the etiologic differential diagnoses in cases of infectious pulmonary disease with a disseminated, nodular lung pattern.

Comparison of In Vitro Bacterial Susceptibility to Common and Novel Equine Wound Care Dressings.

Antimicrobial resistance is becoming a problem of concern in the veterinary field, necessitating the use of effective topical treatments to aid the healing of wounds. Honey has been used for thousands of years for its medicinal properties, but in recent years medical-grade Manuka honey has been used to treat infected wounds. The goal of this study was to determine the relative susceptibility of four common equine wound pathogens to ten different types of antimicrobial agents based on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The pathogens studied include ATCC lab-acclimated Pseudomonas aeruginosa, Escherichia coli, and methicillin-resistant Staphylococcus aureus and one from an equine sample submitted to the Colorado State Veterinary Diagnostic Laboratory (Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus)). An additional goal of the study was to describe the comparison of bactericidal activity of medical-grade Manuka honey, local honey, and commercial, food-grade honey to other commonly used wound dressings (20% hypertonic saline, silver sulfadiazine cream, PHMB gauze, and PHMB foam). The objective is to provide veterinary practitioners with comparative data on the use of a variety of antimicrobial dressings for inhibiting the growth of common wound bacteria. MIC and MBC for Manuka, store, and local honeys were comparable to those of sterile gauze, sugar, and hypertonic saline. Across bacterial species, local honey proved to have more bactericidal activity when compared to Manuka honey and commercial, food-grade honey. The MIC and MBC for PHMB gauze and foam was consistently at a higher dilution compared to the other antimicrobials. The majority of antimicrobials exhibited stronger inhibitory and bactericidal activity against a Streptococcus zooepidemicus isolate obtained from a wound compared to other bacteria that were ATCC lab-acclimated. Additional research for in vivo applications needs to be done to see whether differences exist in effective wound management.

Setting clinically relevant thresholds for the notification of canine disease outbreaks to veterinary practitioners: an exploratory qualitative interview study.

The Small Animal Veterinary Surveillance Network (SAVSNET) has developed mathematical models to analyse the veterinary practice and diagnostic laboratory data to detect genuine outbreaks of canine disease in the United Kingdom. There are, however, no validated methods available to establish the clinical relevance of these genuine statistical outbreaks before their formal investigation is conducted. This study aimed to gain an actionable understanding of a veterinary practitioner's preferences regarding which outbreak scenarios have a substantial impact on veterinary practice for six priority canine diseases in the United Kingdom. An intensity sampling approach was followed to recruit veterinary practitioners according to their years of experience and the size of their practice. In-depth semi-structured and structured interviews were conducted to describe an outbreak notification and outbreak response thresholds for six canine endemic diseases, exotic diseases, and syndromes. These thresholds reflected participants' preferred balance between the levels of excess case incidence and predictive certainty of the detection system. Interviews were transcribed, and a thematic analysis was performed using NVivo 12. Seven interviews were completed. The findings indicate higher preferred levels of predictive certainty for endemic diseases than for exotic diseases, ranging from 95 to 99% and 80 to 90%, respectively. The levels of excess case incidence were considered clinically relevant at values representing an increase of two to four times in the normal case incidence expectancy for endemic agents, such as parvovirus, and where they indicated a single case in the practice's catchment area for exotic diseases such as leishmaniosis and babesiosis. This study's innovative methodology uses veterinary practitioners' opinions to inform the selection of a notification threshold value in real-world applications of stochastic canine outbreak detection models. The clinically relevant thresholds derived from participants' needs will be used by SAVSNET to inform its outbreak detection system and to improve its response to canine disease outbreaks in the United Kingdom.

Retrospective analysis of antimicrobial resistance in bacterial pathogens from pet rabbits in Hong Kong, 2019-2022.

Antimicrobial resistance (AMR) is a growing threat to human and animal health. Data are limited on the prevalence of resistant bacteria in pet rabbits. Therefore, we aimed to identify prevalent bacterial infections and AMR profiles among pet rabbits in Hong Kong (HK). Our search of the CityU Veterinary Diagnostic Laboratory (VDL) database found 301 cases of pet rabbits submitted for bacteriologic and antimicrobial susceptibility testing by veterinarians at 20 exotic veterinary clinics across HK between 2019 and 2022. The rabbits were of 8 different breeds and had a median age of 6.5 y, with 54.8% males, 40.2% females, and 5% unspecified. Of the 301 samples received, 168 (55.8%) had positive bacterial growth; 125 (74.4%) had single bacterial isolates, and 43 (25.6%) had mixed cultures. Cultures included Enterococcus faecalis (21.3%) as the most frequently isolated gram-positive bacterium, followed by Streptococcus intermedius (12.5%), and Staphylococcus aureus (11.3%). The most frequently isolated gram-negative bacteria were Pseudomonas aeruginosa (18.1%), followed by Escherichia coli (8.3%), Pasteurella multocida (6.9%), and Klebsiella pneumoniae (4.2%). Approximately 83% of the isolates had acquired resistance to at least one antimicrobial agent, and 49.4% were multidrug-resistant. The isolated bacteria had high levels of resistance to penicillin (69.8%), clindamycin (47.4%), and doxycycline (46.9%). Our findings highlight the high levels of AMR in bacteria isolated from pet rabbit clinical samples in HK; many of these bacteria are zoonotic and pose a public health threat.

Microbiological Survey and Evaluation of Antimicrobial Susceptibility Patterns of Microorganisms Obtained from Suspect Cases of Canine Otitis Externa in Gran Canaria, Spain.

A retrospective study of microbiological laboratory results from 2020 to 2022, obtained from a veterinary diagnostic laboratory of the island of Gran Canaria, Spain, focused on canine otitis cases, was performed. The objective of this study was to analyze the pathogen distribution, antimicrobial susceptibility, prevalence of multidrug resistant phenotypes and the role of coinfections in otitis cases in order to provide up-to-date evidence that could support effective control strategies for this prevalent pathology. A total of 604 submissions were processed for the diagnosis of canine external otitis. Of the samples analyzed, 472 were positive for bacterial or fungal growth (78.1%; 95% CI: 74.8-81.4%). A total of 558 microbiological diagnoses were obtained, divided in 421 bacterial (75.4%; 95% CI: 71.8-79.0%) and 137 fungal (24.6%; 95% CI: 20.9-28.1%) identifications. Staphylococcus pseudintermedius, Malassezia pachydermatis and Pseudomonas aeruginosa were the most prevalent microorganisms detected in clinical cases of otitis. High level antimicrobial resistance was found for Pseudomonas aeruginosa (30.7%), Proteus mirabilis (29.4%), Staphylococcus pseudintermedius (25.1%) and Escherichia coli (19%). Multidrug-resistant phenotypes were observed in 47% of the bacteria isolated. In addition, a 26.4% prevalence of methicillin-resistant Staphylococcus pseudintermedius was detected. The high prevalence of antimicrobial resistant phenotypes in these bacteria highlights the current necessity for constant up-to-date prevalence and antimicrobial susceptibility data that can support evidence-based strategies to effectively tackle this animal and public health concern.

Evidence of Active Orbivirus Transmission in 2016 in Kansas and Nebraska.

Retrospective serological and case diagnostic data of endemic bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) provide evidence of viral transmission among livestock and wildlife from 2016 in Kansas and Nebraska. Serological testing of mature cattle in nine distinct regional zones of Kansas revealed 76% to 100% had detectable antibodies to BTV and/or EHDV. Specimens tested in the Kansas Veterinary Diagnostic Laboratory (55 submissions) were 51% test positive for antibodies to BTV and/or EHDV. Specimens tested in the Nebraska Veterinary Diagnostic Center (283 submissions) were 25% test positive for antibodies to BTV and/or EHDV. Low disease incidence in white-tailed deer and other susceptible wild ungulates was observed during 2016. However, there were no confirmed reports of disease in livestock in either state. The reasons for emergence of significant clinical disease in livestock and wildlife populations remain undefined.