Bacterial colonization of the ovarian bursa in dogs with clinically suspected pyometra and in controls

Antimicrobials administration, treatment outcome and bacterial susceptibility in canine pyometra cases subjected to ovariohysterectomy

Pyometra is a bacterial uterine infection that frequently affects intact older bitches. The treatment of choice is ovariohysterectomy, often associated with perioperative antimicrobial therapy. The aim of this retrospective investigation was to evaluate the antibiotic choice at different administration times (pre-surgery, at surgery/during hospitalization, and post-surgery) against complications and outcomes, considering the susceptibility profile of bacteria. The medical records of 51 bitches referred to the Veterinary Teaching Hospital of the University of Turin (January 2021-November 2023) and subjected to ovariohysterectomy and bacteriological examination (bacterial culture and susceptibility tests) of the uterine exudate, were analysed. All animals had a positive outcome without surgical site infections, with a longer hospitalization time in case of peritonitis or sepsis; antimicrobials were administered for an average of 7 days. Comparing the susceptibility of the isolated bacteria towards the antimicrobials administered before, during and after surgery, complete efficacy was observed in 42 %, 46 % and 50 % of cases, respectively. In addition, 5/16 peritonitis cases were treated with an in vitro ineffective antimicrobial, and 30 % of the bitches never received a fully effective antibiotic, according to susceptibility tests using the minimum inhibitory concentration method (MIC). Cephazolin resulted the best option for Escherichia coli, the most frequently isolated bacterium. Our study confirms that pyometra has a good prognosis following ovariohysterectomy and antibiotic administration. Monitoring the clinical evolution without changing the antibiotic according to bacterial susceptibility could represent the right choice in uncomplicated cases. Evaluation of outcomes without postoperative antibacterial treatment or with a shorter course would be another topic worth investigating, with the aim to judiciously reduce the use of antibiotics.

Antimicrobial susceptibility and production of virulence factors by bacteria recovered from bitches with pyometra

Pyometra is one of the most common diseases in adult female dogs, characterized by a suppurative bacterial infection of the uterus with accumulation of inflammatory exudate and a variety of local and systemic clinical manifestations. This study aimed to identify the bacteria within the uterine content and vaginal canal of bitches with pyometra and evaluate their antimicrobial susceptibility and production of virulence factors. Uterine and vaginal content were collected with sterile swabs from 30 bitches diagnosed with pyometra. Bacteria were identified and assessed for their antimicrobial susceptibility and production of virulence factors, including biofilms, siderophores, proteases and hemolysins, both in planktonic and biofilm forms. A total of 82 bacterial isolates (35 uterus, 47 vagina), belonging to 21 species, were identified, with Escherichia coli as the most prevalent species (32/82, 39%). As for susceptibility, 39/79 (49.4%) isolates were resistant to one or more drugs, with resistance proportion among Gram-positive bacteria (87.5%) higher (p < .05) than that observed for Gram-negative bacteria (32.7%). Four coagulase-negative Staphylococcus species were resistant to methicillin. Regarding virulence, the isolates had low production of biofilms, siderophores, proteases and hemolysins, suggesting that the occurrence of pyometra might be more associated with host-related factors than bacterial virulence.

Is Chlamydia to Blame for Koala Reproductive Cysts?

A significant threat to koala populations is infection from Chlamydia, which results in disease and death. Wild koalas with Chlamydia infections are admitted to wildlife hospitals and treated with antibiotics; however, up to 50% of koalas that present to wildlife hospitals do not survive. A major contributor to high mortality is the development of reproductive cysts, resulting in female infertility and euthanasia. However, the diagnosis of reproductive disease is limited to ultrasound with no further investigations. This communication highlights reports of histological and microbiological findings, the accuracy of ultrasound to necropsy reports and other possible causes for reproductive cyst development previously reported in other hosts. Our conclusions identify a significant knowledge gap in the aetiology of koala reproductive cysts and highlight the urgent need for future investigations.

PERFIL DE RESISTÊNCIA DE ISOLADOS DE Escherichia coli A PARTIR DE PIOMETRA CANINA

Resumo A piometra é uma enfermidade endotelial que acomete com mais frequência as fêmeas adultas e ativas reprodutivamente. Caracteriza-se por inflamação e acúmulo de exsudato na cavidade uterina que geralmente está associada a infecções bacterianas. O presente estudo objetivou avaliar o perfil de resistência de isolados de Escherichia coli a partir do conteúdo uterino de 42 fêmeas caninas, atendidas no Setor de Cirurgia de Pequenos Animais do Hospital de Medicina Veterinária da Universidade Federal da Bahia, com diagnóstico de piometra. Para a realização da análise bacteriológica, uma amostra do conteúdo uterino foi obtida imediatamente após o ato cirúrgico de ovariosalpingohisterectomia terapêutica (OSH) e encaminhada para o laboratório. Após análise microbiológica observou-se uma predominância da bactéria Escherichia coli em 40,5% (15/37). As cepas de Escherichia coli isoladas apresentaram os maiores índices de resistência aos antimicrobianos eritromicina (93,3%), azitromicina (80%), ampicilina, amoxacilina e cefalotina (40% cada). Tal estudo reforça a necessidade da realização do exame microbiológico com finalidade epidemiológica e correta aplicação terapêutica, evitando, com isso, a utilização indiscriminada de antimicrobianos e potencial surgimento de estirpes multirresistentes.