Feline Dermatophytic Pseudomycetoma ( Microsporum canis ) Infection with Actinobactoer ursingii in a British Shorthair Cat: A Case Report in Thailand

Bacterial agents are considered important pathogens causing external otitis in dogs. It is essential to carry out bacterial culture and antimicrobial susceptibility test in the case of otitis externa, particularly for chronic or recurring cases. Sterile swab samples were obtained from terminal part of vertical ear canals of 74 dogs with otitis externa for cytology, bacterial culture and antimicrobial susceptibility test. Cytologic smears were stained using Gram and Giemsa staining methods. Aerobic bacterial culture performed on blood agar and MacConkey agar. Among total number of 92 isolated bacteria, 68 were Staphylococcus intermedius. Other isolated bacteria included: Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Pasteurella canis, and six other species of coagulase-negative Staphylococcus. Antimicrobial susceptibility test were performed for all isolated bacteria using 14 antibiotics. Based on the results of this study, all isolated Staphylococcus spp. were sensitive to amikacin, enrofloxacin, and rifampin, and had low resistance to gentamicin, cephalothin and ceftriaxone. More than half of gram-positive isolates were resistant to penicillin and ampicillin. Generally, all isolated gram-negative bacteria, were sensitive to amikacin and enrofloxacin, and had low resistance to ceftriaxone and gentamicin. They were highly resistant to penicillin, eythromycin, and cephalothin. Regarding the results of this study, in cases of uncomplicated otitis externa, it is possible to select antimicrobial drugs merely based on cytology, but it is recommended to perform bacterial culture and antimicrobial susceptibility test. However, in complicated or refractory cases, antimicrobials should be selected based on bacterial culture and antimicrobial susceptibility test.

Dermatophytic pseudomycetoma (DPM) is a rarely reported invasive fungal infection of humans and animals, especially cats. This study aimed to identify dermatophytes, breed associations, and the frequency of extracutaneous (EC) involvement in feline DPM. Electronic records and formalin-fixed paraffin-embedded tissue (FFPET) from 32 suspected DPM cases in 30 cats were retrieved from a diagnostic laboratory between 2018 and 2024. To confirm DPM and molecular identity, DNA was extracted from FFPET for ITS2 sequencing, and immunohistochemistry was performed on PCR-negative cases. All cases were confirmed as DPM. Microsporum canis was the only dermatophyte identified. The sensitivity and specificity of ITS2 sequencing for M. canis identification in FFPET were 22/32 (68.8%) and 21/22 (95.5%), respectively. Exotic (36.7%) and Persian (23.3%) but not British breeds (26.3%) were over-represented compared to feline admissions at an affiliated veterinary hospital (8.5%, p < 0.001; 3%, p < 0.001; 21.6%, p = 0.817, respectively). Five cases (16.7%) had EC lesions; two had intra-abdominal masses; two had oral cavity masses, including one which extended into the cranial vault; and one had superficial cervical lymph node invasion. Exotic and Persian breeds are over-represented for DPM and M. canis is the primary cause. EC lesions of DPM may occur more commonly than previously thought.

O pseudomicetoma dermatofítico (PMD) é uma profunda infecção dérmica, causada por fungos, sendo o Microsporum canis o agente etiológico mais frequentemente envolvido. O objetivo do presente trabalho é relatar um caso de pseudomicetoma em um gato persa e alertar os médicos veterinários para incluir a doença como diagnóstico diferencial em dermatopatias em gatos, principalmente os da raça persa. Um felino macho, da raça Persa, de três anos, veio para atendimento apresentando 22 nódulos subcutâneos, distribuídos em todo corpo, com diâmetros que variavam de 2 a 8 centímetros, inclusive dentro do pavilhão auricular direito. Realizou-se raspado cutâneo e citologia aspirativa por agulha fina, obtendo resultados pouco conclusivos. Após a realização de exérese cirúrgica de grande parte dos nódulos e encaminhamento para exame histopatológico, obteve-se o diagnóstico de PMD. Após tratamento com itraconazol 10mg/kg SID por 5 meses houve completa remissão do quadro. A excisão cirúrgica foi essencial para a resolução do quadro, que juntamente com o itraconazol sistêmico tornou o tratamento efetivo para o PMD.

Otitis media (OM) has a high prevalence worldwide and the treatment is crucial because hearing loss in children can lead to growth disorders such as language development disorders. The aim of this study is to analyse the changes in bacterial strains and the trends of antibiotic susceptibility in otitis media with effusion (OME), chronic otitis media (COM) and cholesteatomatous otitis media (Chole OM). This retrospective study involved 2926 patients diagnosed with OME, COM, or Chole OM between January 2000 and December 2020. The clinical data were collected and analysed through chart review from May 2021 to July 2021. Two tertiary medical centres. The 2926 OM patients. An otorrhea sample was collected on the first day of their hospital visit. Middle ear fluid samples for bacterial culture and antibiotics susceptibility test were collected from patients during middle ear surgery, including ventilation tube insertion. In each type of OM, the distribution of bacterial strains in the 2000s and the 2010s was compared. In addition, changes in the detection rate of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PA) and trends in their antibiotic susceptibility over the last 10 years were analysed. The most frequently detected bacterial strains in OME, COM and Chole OM over the study period were coagulase-negative Staphylococcus (CNS) (29.6%), MRSA (24.1%), and PA (20.1%). Compared to the 2000s, the proportion of non-typable Haemophilus influenzae in OME and MRSA in COM increased in the 2010s (27.4%-31.6% and 1.5%-29.5%, respectively). In total three types of OM, although there was no significant trend of change in detection rates of MRSA, PA, and multidrug resistant-P. aeruginosa (MDR-PA) during the last 10 years, resistance to the Quinolone class of MRSA and PA tended to increase (P < .05). The composition of bacterial strains in each types of OM has changed over the past 20 years. Additionally, the antibiotic resistance of MRSA and PA has increased in the last decade. Therefore, when using empirical antibiotics in necessary situations, it is necessary to change to an appropriate antibiotic through a bacterial culture test and antimicrobial susceptibility test.

Dermatophytic pseudomycetoma (DPM), which is a deeper dermal and/or subcutaneous infection of dermatophytes, has been rarely reported in Domestic Korean Short Hair Cats. A 3-year-old, spayed female, domestic Korean Short Hair Cat presented with a history of crusts, nodules, and pruritus for 1 year. At the initial presentation, multifocal ulcerative nodules covered with yellowish grains were noted on her ventral thorax, abdomen, flank, and left hindlimb. Cytology of ulcerative nodules revealed degenerative neutrophils, macrophages, multinucleated giant cells, and hyphae. Histological examination of nodules revealed pyogranulomatous dermatitis with fungal plaques, and Microsporum canis and Staphylococcus aureus were identified in the culture. Therefore, the cat was diagnosed with DPM with secondary pyoderma. Oral itraconazole (10 mg/kg, once a day) was administered, but no significant improvement was observed. Therefore, intralesional (IL) injection of amphotericin B (0.6 mg/nodule) and oral administration of terbinafine (30 mg/kg, twice a day) were administered to the cat. With these medications, ulceration and the number and size of nodules decreased significantly, although large dome-shaped nodules remained. Skin lesions were treated with oral terbinafine and itraconazole administration for 5 months. However, after 6 months, recurrence of multifocal ulcerative nodules was observed, and the cat died 10 months after initial presentation. In this case, IL amphotericin B and oral terbinafine administration were partially effective in DPM treatment, suggesting that this may be an option for DPM treatment. Further studies to determine dose and frequency of IL amphotericin B in the management of DPM are warranted.

Background: Tools are needed to assist in the battle against multi‐drug resistant infections. To ensure rational antimicrobial use, it is crucial to identify infectious agents.Aim of the article: This article highlights the application of culture and susceptibility testing, which will assist practitioners in optimising antimicrobial selection. It describes techniques to obtain a representative sample for analysis and how to maximise pathogen viability during transport and handling. Some of the different methodologies employed for bacterial culture and antimicrobial susceptibility testing will be reviewed with guidance on how to interpret the results. We wholeheartedly support practitioner efforts to detect and characterise bacterial pathogens and hope to provide a useful guide to the analysis of these results so that they can inform therapeutic strategy. By working closely with your local veterinary diagnostic laboratory patient care may be enhanced; maintaining open channels of communication with the microbiologist can also provide context to unexpected results. Bacterial culture and susceptibility testing facilitate appropriate antimicrobial selection and, therefore, play a pivotal role in tackling antimicrobial resistance. It is beholden to veterinarians to learn how to use these tools most effectively.

To describe the antimicrobial susceptibility patterns of the most commonly isolated bacteria cultured from synovial fluid samples from horses with suspected septic synovitis treated at an equine referral hospital between May 1, 2008, and September 24, 2017. 131 synovial fluid samples from 108 client-owned horses. A retrospective medical record search was conducted to identify horses with suspected septic synovitis and results of synovial fluid bacterial culture and antimicrobial susceptibility testing. Data collected included signalment, known or suspected origin of synovial contamination, synovial structures affected, antimicrobial treatment, and results of synovial fluid cytologic evaluation and bacterial culture and susceptibility testing. Horses were grouped as adults (≥ 6 months old) or foals (< 6 months old). Results of bacterial culture were positive for 34 of 70 (49%) and 18 of 61 (30%) samples from 68 adult horses and 40 foals, respectively. Gram-positive bacteria were more common in adult horses, whereas gram-negative bacteria were more common in foals. No multidrug-resistant microorganisms were identified. For adult horses, 92% (23/25) of gram-positive isolates tested with penicillin and gentamicin were susceptible to the combination. For foals, 94% (15/16) of isolates tested with penicillin, gentamicin, or both had susceptibility to 1 or both antimicrobials. Periodic review of bacterial profiles and antimicrobial susceptibility in horses with septic synovitis can help to detect early changes in bacterial pressure and antimicrobial resistance. Findings suggested that in the geographic area we serve, a combination of penicillin and gentamicin would be an effective empirical antimicrobial treatment for most horses with septic synovitis while results of bacterial culture and susceptibility are pending.

Dermatophytic pseudomycetoma is an atypical form of dermatophytosis where the infection is located in the deep dermal and subcutaneous tissues. Although rare, it is most commonly associated with Microsporum canis or Trichophyton sp. It has been reported in cats, dogs and horses. To describe the clinical and pathological findings of dermatophytic pseudomycetoma caused by M. canis and Trichophyton sp. in two domestic ferrets. Two pet ferrets (Mustela putorius furo). Case report. Two ferrets were diagnosed with dermatophytic pseudomycetoma confirmed by histological examination of tissue and fungal culture. In both cases, ferrets presented with several cutaneous firm nodules 0.6-3 cm in diameter. Microscopic lesions revealed multifocal nodular pyogranulomatous inflammation with intralesional fungi. To the best of the authors' knowledge, this is the first description of dermatophytic pseudomycetoma in domestic ferrets. This disease should be included in the differential diagnosis of nodular dermatopathies in this species.

To identify a method for developing antibiograms for use in companion animal private practices (PPs). Reports (n = 532) of aerobic bacterial culture and antimicrobial susceptibility testing performed between January 1, 2018, and December 31, 2018, at 11 PPs and 1 academic primary care practice (APCP). Data extracted from reports included patient identification number, laboratory accession number, patient signalment, collection method, body site, and results of bacterial culture and antimicrobial susceptibility testing. A custom antibiogram was then constructed with the help of commonly available software by adapting methods used by human hospitals. Susceptibility patterns of bacteria isolated by PPs and the APCP were compared to identify challenges associated with collating data from multiple laboratories. 4 bacterial species (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius) and 3 bacterial groups (Enterobacteriaceae, Enterococcus spp, and coagulase-positive Staphylococcus spp) met the minimum requirement of ≥ 15 isolates for construction of an antibiogram. For urine samples, 3 bacterial species and 2 bacterial groups met the minimum requirement of ≥ 10 isolates. For samples from skin, 2 bacterial species and 2 bacterial groups met the minimum requirement of ≥ 10 isolates. Patient signalment, sample source, and distribution of bacterial isolates were similar between PP and APCP patients. Results demonstrated that it was feasible to adapt existing guidelines for developing antibiograms in human medicine to the veterinary outpatient setting. Use of antibiograms could aid in empirical antimicrobial drug selection in a manner that supports antimicrobial stewardship principles.

ABSTRACT: Pyometra is the most common reproductive disease in female dogs, characterized by the accumulation of purulent content in the uterus. Its etiology is multifactorial, primarily involving hormonal and bacterial factors, with Escherichia coli being the most frequently isolated pathogen. International guidelines recommend bacterial culture and antimicrobial susceptibility testing of uterine content before or, if not feasible, after ovariohysterectomy. However, due to the time required to perform these tests, empirical antibiotic therapy is commonly prescribed, potentially contributing to antimicrobial resistance and treatment failure. Given that E. coli causing pyometra often originates from the intestinal microbiota, we hypothesized that isolates from rectal swabs could serve as predictors of the antimicrobial resistance profile of the E. coli causing pyometra. To evaluate this possibility, this study assessed the antimicrobial susceptibility of E. coli isolates from the uterine content and rectal swabs of bitches with pyometra and evaluated whether there is an association between the resistance profiles at these two sites. Samples from 72 dogs diagnosed with pyometra were collected for bacterial culture and antimicrobial susceptibility testing. E. coli was identified in 40 uterine content samples (55.6%) and 59 rectal swabs (81.9%) using species-specific PCR. E. coli isolates from rectal swabs exhibited higher resistance rates to commonly used antibiotics for pyometra treatment, including amoxicillin/clavulanic acid, ampicillin, enrofloxacin, and doxycycline (P &lt; 0.05). The presence of susceptible isolates in rectal swabs is strongly associated with susceptibility in uterine isolates, yielding a positive predictive value up to 100%. These findings suggested that rectal swab isolates could serve as a reliable predictor of uterine E. coli susceptibility, providing a rapid and non-invasive tool to guide antimicrobial selection for pyometra treatment.

Isolation of aerobic bacteria from abscesses and wounds in rabbits and antibiotic susceptibility testing of Staphylococcus spp. and Pseudomonas spp. isolates

Dermatophyte infection is almost exclusively a superficial cutaneous mycosis usually confined to the stratum corneum of nails and hairs of normal hosts. Deep cutaneous and subcutaneous infections due to dermatophytes are exceedingly rare and usually limited to immunosuppressed individuals. These infections remain chronic and persist in spite of treatment. We report two clinical cases of disseminated dermatophytic pseudomycetoma caused by Microsporum gypseum and Microsporum canis in immunosuppressed patients. Patient 1, in 2008, showed improvement with fluconazole, cephalothin, and terbinafine treatment for Microsporum gypseum. After suspension of the treatment, new lesions appeared and culture from material was positive. In 2009, she presented confluent papules and nodules forming plaques on her face and neck with the isolation of Microsporum canis. Clinical response to this treatment was poor. Patient 2 was affected by both tinea corporis due to Trichophyton rubrum and dermatophytic pseudomycetoma caused by Microsporum canis. The response to treatment was successful with oral itraconazole and local surgical excision. It is important to recognize these atypical presentations of dermatophytic infections in immunosuppressed patients, which may warrant a more aggressive treatment in order to achieve resolution.

Association of bacterial isolates and antimicrobial susceptibility between prostatic fluid and urine samples in canine prostatitis with concurrent cystitis

To investigate bacterial culture practices in veterinary clinics, with an emphasis on laboratory biosafety and on quality of laboratory practices. Survey-based prospective study. 166 veterinarians. Veterinarians were recruited through the Veterinary Information Network (an Internet-based network restricted to veterinary personnel). All Network-registered veterinarians were eligible to participate. A standardized questionnaire regarding bacterial culture practices in veterinary clinics was completed electronically by study participants. 720 veterinarians completed the survey; 166 (23%) indicated that bacterial culture was performed in his or her clinic. Clinic practices ranged from preliminary aerobic bacterial culture only with submission of isolates to a diagnostic laboratory for further testing (93/160 [58%]) to bacterial culture, identification, and antimicrobial susceptibility testing (19/160 [12%]). Most commonly, urine samples were cultured (151/162 [93%] clinics). Several problematic practices were identified regarding quality and quality control, including inadequate facilities, equipment, supervision, interpretation of data, and culture methods. Biosafety infractions were also common, including inadequate laboratory location, lack of biosafety protocols, and dangerous disposal practices. Ninety-four percent of respondents stated that continuing education regarding culture practices and laboratory safety would be useful. Data confirmed that bacterial culture was commonly performed in clinics, but that major deficiencies in laboratory methods were widespread. These could result in negative effects on testing quality and increased risk of laboratory-acquired infections among clinic personnel. Veterinary practices in which bacterial cultures are performed must ensure that adequate equipment, facilities, personnel, and training are provided to enable accurate and safe sample testing.

To determine frequency of urinary tract infections (UTIs) in catheterized dogs that had intervertebral disk disease (IVDD) or disease other than IVDD and compare bacterial culture and susceptibility testing results for catheterized and noncatheterized dogs with UTIs. Retrospective cohort study. 147 catheterized dogs (105 with IVDD and 42 with other diseases) and 99 noncatheterized dogs with UTIs. Medical records were reviewed for signalment, history, clinical problem, duration of urinary tract catheterization, administration of drugs, and urine bacterial culture and susceptibility testing results. Forty-two percent (44/105) of dogs with IVDD and 55% (23/42) of dogs with other diseases had UTIs; this difference was not significant. For catheterized dogs, the odds of UTI were increased by 20% for each year increase in age, 27% for each day increase in duration of catheterization, and 454% with antimicrobial administration. Escherichia coli and Proteus spp were more frequently isolated from noncatheterized dogs, whereas Enterobacter spp and Staphylococcus spp were more frequently isolated from catheterized dogs. There was no significant difference in frequency of 1, 2, or 3 isolates between groups. Proportions of antimicrobials to which the most frequently isolated bacteria were resistant were not significantly different between groups. Results suggested that urinary tract catheterization is a reasonable alternative for management of dogs with urinary bladder dysfunction, but that duration of catheterization should be minimized and indiscriminate antimicrobial administration to dogs with indwelling urinary catheters should be avoided.