The Site of Origin of Canine Abdominal Masses Correlates with the Risk of Malignancy: Retrospective Study of 123 Cases.

The detection of an abdominal mass represents a common finding in clinical practice. The aim of this study was to retrospectively describe the tissue distribution and diagnosis of abdominal masses amenable to surgical removal in a canine population. Dogs with abdominal masses with a minimum diameter of 3 cm were selected. Cases were classified, based on the anatomical location, as splenic, gastrointestinal, hepatobiliary, genital, and masses not associated with any organ. Masses were surgically removed and formalin-fixed for the histological examination. Collected data were statistically analyzed. A total of 123 masses were collected from 122 dogs. Sixty-nine masses were classified as malignant neoplasia, 15 as benign, and 39 as non-neoplastic. The abdominal masses were 5.8-fold more likely to be malignant if located in the gastrointestinal tract (p = 0.01). A significant association between the size and the site of the masses was identified, the masses not associated with any organ being larger than the genital and splenic lesions (p = 0.008). This case series describes the most frequent location in association with the histopathological diagnosis of canine abdominal masses and suggests that the gastrointestinal location was related to a higher risk of representing a malignant neoplasm.

High Intrinsic Expression of P-glycoprotein and Breast Cancer Resistance Protein in Canine Mammary Carcinomas Regardless of Immunophenotype and Outcome.

P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) are major actors in multidrug resistance (MDR) phenomenon in both human and canine mammary carcinomas (CMCs). The aim of this study was to investigate an association between the intrinsic expression of P-gp and BCRP compared to the immunophenotypes and outcome in CMCs. Fifty CMCs were evaluated at immunohistochemistry (IHC) for P-gp, BCRP, Estrogen receptor alpha (ER), Progesterone receptors (PR), Human Epidermal Growth Factor Receptor type 2 (HER2), basal cytokeratins 5/6 (CK5/6), Epidermal Growth Factor Receptor 1 (EGFR), and Ki67 proliferation index. P-gp and BCRP positive cases were, respectively, 52% and 74.5%, with a significantly higher expression of BCRP than P-gp. Five immunophenotypes were defined in 37 out of 50 CMCs: 9 (24.3%) Luminal A, 5 (13.5%) Luminal B, 9 (24.3%) HER2 overexpressing, 9 (24.3%) Triple-negative basal-like, and 5 (13.5%) Triple-negative non-basal-like. In all CMCs at least one marker was expressed. Follow-up data were available for 25 animals. The average cancer-specific survival was 739 ± 444 days. A number of CMCs bear a high expression of P-gp and BCRP but no significant association was found between their expression and the immunophenotypes, Ki67 index, the histological grade, and tumor-related death.

Hospitalized Pets as a Source of Carbapenem-Resistance.

The massive and irrational use of antibiotics in livestock productions has fostered the occurrence and spread of resistance to "old class antimicrobials." To cope with that phenomenon, some regulations have been already enforced in the member states of the European Union. However, a role of livestock animals in the relatively recent alerts on the rapid worldwide increase of resistance to last-choice antimicrobials as carbapenems is very unlikely. Conversely, these antimicrobials are increasingly administered in veterinary hospitals whose role in spreading bacteria or mobile genetic elements has not adequately been addressed so far. A cross-sectional study was carried out on 105 hospitalized and 100 non-hospitalized pets with the aim of measuring the prevalence of carbapenem-resistant Gram-negative bacteria (GNB) colonizing dogs and cats, either hospitalized or not hospitalized and estimating the relative odds. Stool samples were inoculated on MacConkey agar plates containing 1 mg/L imipenem which were then incubated aerobically at 37°C ± 1 for 48 h. Isolated bacteria were identified first by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and were confirmed by 16S rRNA sequencing. The genetic basis of resistance was investigated using PCR methods, gene or whole genome sequencing (WGS). The prevalence of pets harboring carbapenem-resistant bacteria was 11.4 and 1.0% in hospitalized and not-hospitalized animals, respectively, with an odds ratio of 12.8 (p < 0.01). One pet carried two diverse isolates. Overall, 14 gram-negative non-fermenting bacteria, specifically, one Acinetobacter radioresistens, five Acinetobacter baumannii, six Pseudomonas aeruginosa and two Stenotrophomonas maltophilia were isolated. The Acinetobacter species carried acquired carbapenemases genes encoded by bla NDM-1 and bla OXA-23. In contrast, Pseudomonas phenotypic resistance was associated with the presence of mutations in the oprD gene. Notably, inherent carbapenem-resistant isolates of S. maltophilia were also resistant to the first-line recommended chemotherapeutic trimethoprim/sulfamethoxazole. This study estimates the risk of colonization by carbapenem-resistant non-fermenting GNB in pets hospitalized in veterinary tertiary care centers and highlights their potential role in spreading resistance genes among the animal and human community. Public health authorities should consider extending surveillance systems and putting the release of critical antibiotics under more strict control in order to manage the infection/colonization of pets in veterinary settings.

A comparison of the reliability of two gene targets in loop-mediated isothermal amplification assays for detecting leptospiral DNA in canine urine.

We compared 2 novel loop-mediated isothermal amplification (LAMP) assays that target either the 16S ribosomal RNA ( rrs) gene or the gene encoding a 32-kDa leptospiral lipoprotein ( lipL32) in order to assess the effect of the target on the accuracy of the LAMP assays. The most sensitive assay was the rrs assay with a limit of detection (LOD) of 1.2 × 101 genome equivalents per reaction. The novel lipL32 assay showed an LOD of 1.2 × 102 genome equivalents per reaction. Both assays showed adequate specificity when tested against a collection of bacteria commonly found in voided canine urine. However, when field samples were assayed, the rrs assays gave many false-positive results and a poor positive predictive value of 8.33%. In conclusion, even if the LAMP assay is used in low prevalence areas, the lipL32 assay would be preferable. Conversely, the higher analytical sensitivity of the rrs assay could be effectively used as a screening test in endemic areas with high disease prevalence, followed by confirmation of the positive results using the lipL32 assay.

A comparison of two real-time polymerase chain reaction assays using hybridization probes targeting either 16S ribosomal RNA or a subsurface lipoprotein gene for detecting leptospires in canine urine.

Leptospires are excreted in the urine of infected animals, and the prompt detection of leptospiral DNA using polymerase chain reaction (PCR) is increasingly being used. However, contradictory data has emerged concerning the diagnostic accuracy of the most popular PCR assays that target either the 16S ribosomal RNA (rrs) or the subsurface lipoprotein (LipL32) genes. In order to clarify the effect of the gene target, a novel hydrolysis probe-based, quantitative real-time PCR (qPCR) assay targeting the LipL32 gene was developed, validated, and then compared directly to the previously described rrs hydrolysis probe-based qPCR using a convenience collection of canine urine samples. The novel LipL32 qPCR assay was linear from 5.9 × 10(6) to 59 genome equivalents per reaction. Both the LipL32 and the rrs qPCR assays showed a limit of detection of 10 target copies per reaction indicating an approximately equivalent analytical sensitivity. Both assays amplified all 20 pathogenic leptospiral strains tested but did not amplify a representative collection of bacteria commonly found in voided canine urine. When the field samples were assayed, 1 and 5 out of 184 samples yielded an amplification signal in the LipL32 and rrs assays, respectively. Nevertheless, when the limit of detection was considered as the cutoff for interpreting findings, the 4 discordant cases were judged as negative. In conclusion, our study confirmed that both LipL32 and rrs are suitable targets for qPCR for the detection of leptospiral DNA in canine urine. However, the rrs target requires the mandatory use of a cutoff value in order to correctly interpret spurious amplifications.

Detection of Wolbachia DNA in blood for diagnosing filaria-associated syndromes in cats.

A fundamental role for the endosymbiotic bacteria Wolbachia pipientis in the pathogenesis of Dirofilaria immitis infections has emerged in recent years. Diagnostic opportunities arising from this breakthrough have not yet been fully exploited. This study was aimed at developing conventional and real-time PCR assays to carry out a molecular survey in a convenience sample of cats living in an area where D. immitis is endemic and to evaluate the detection of bacterial DNA in blood as a surrogate assay for diagnosing filaria-associated syndromes in cats. COI and FtsZ loci were used as targets for D. immitis and Wolbachia PCR assays, respectively, and real-time TaqMan PCR assays were used only for Wolbachia. A convenience sample of 307 disease-affected or healthy cats examined at a University facility were PCR tested, and their medical records were investigated. Conventional nested PCR for Wolbachia amplified the endosymbionts of both D. immitis and D. repens, while real-time PCR was highly specific only for the former. Observed prevalences of 0.3 and 10.4% were found using conventional nested PCR assays for D. immitis and real-time PCR for Wolbachia, respectively. Similar prevalences were established using the Wolbachia nested PCR (98% concordance with real-time PCR). The group of Wolbachia-positive samples had a significantly higher proportion of subjects with respiratory signs (29.0% versus 9.7%; P = 0.002). The findings of this study indicate that a highly sensitive PCR assay can be used to detect the Wolbachia organism in the peripheral blood of cats with respiratory signs.

Frequency of the allelic variant of the PTPLA gene responsible for centronuclear myopathy in Labrador Retriever dogs as assessed in Italy.

Centronuclear myopathy (CNM) is an autosomal recessive hereditary disease affecting Labrador Retriever dogs. The disease is characterized by muscle lesions, typically encompassing reduction in the number and atrophy of type II fibers, and is caused by a short interspersed repeat element insertion in exon 2 of the protein tyrosine phosphatase-like member A. The actual allele frequency is unknown; a study was undertaken to ascertain it using a convenience-sample population composed of 217 Labrador Retrievers. In addition to 3 subjects already diagnosed with CNM, used as positive controls for polymerase chain reaction, only 2 unrelated dogs were heterozygous wild-type/mutation (wild-type/mut). Thus, the frequency of the CNM allele observed in the present study was 1.8% and 0.47% when including and excluding the 3 mut/mut homozygous cases, respectively. Based on the Hardy-Weinberg exact test (P  =  1.00), the genotype frequency without the CNM-affected dogs was in agreement with the Hardy-Weinberg equilibrium. Assuming the Hardy-Weinberg equilibrium law, the expected frequency of the homozygous mutated genotype was calculated to be approximately 0.00005, which corresponds to 1 case of CNM out of 20,000 dogs. In conclusion, the present study indicates that the CNM allele is present but rare in a convenience sample of Labrador Retrievers in Italy.