Antimicrobial resistance and virulence gene profiles in P. multocida strains isolated from cats

Molecular characterization of Pasteurella multocida from cats and antibiotic sensitivity of the isolates

BACKGROUND

Companion animals, including dogs and cats, are frequently identified as sources of Pasteurella multocida, a bacterium that can be transmitted to humans and cause infections.

OBJECTIVES

This survey defines the prevalence, antibiotic sensitivity, capsular types, lipopolysaccharide (LPS) types and virulence factors of P. multocida isolated from cats.

METHODS

A total of 100 specimens from various cat breeds were collected. P. multocida was characterized using both biochemical tests and PCR. Genotypes of isolates were determined using capsular and LPS typing methods. Additionally, virulotyping was performed by detecting the presence of 12 virulence-associated genes. Disk diffusion was used to determine the antibiotic sensitivity of the isolates.

RESULTS

The prevalence of P. multocida in cats was 29%. Among the isolates, the majority were capsular type A (96.5%) and type D (3.4%), with a predominant presence of type A. Twenty-six of the isolates (89.66%) belonged to LPS genotype L6, whereas three isolates (10.3%) belonged to genotype L3. Among the 12 virulence genes examined, sodC, oma87, ptfA, nanB and ompH showed remarkable prevalence (100%). The toxA gene was detected in four isolates (13.8%). Variations were observed in other virulence genes. The nanH gene was present in 93.1% of the isolates, whereas the pfhA gene was detected in 58.6% of the isolates. The exbD-tonB, hgbB, sodA and hgbA genes showed prevalence rates of 96.5%, 96.5%, 96.5% and 82.8%, respectively. Additionally, particular capsule and LPS types were associated with specific virulence genes. Specifically, the toxA and pfhA genes were found to be more prevalent in isolates with capsular type A and LPS genotype L6. Most isolates were resistant to ampicillin, clindamycin, lincomycin, streptomycin and penicillin.

CONCLUSIONS

According to this epidemiological and molecular data, P. multocida from cats possess several virulence-associated genes and are resistant to antimicrobial medicines commonly used in humans and animals. Thus, it is crucial to consider the public health concerns of P. multocida in humans.

Unique presentation of an intramuscular abscess caused by Bacteroides pyogenes in the setting of a cat bite: A case report

Cat bites are a relatively common emergency department presentation. The most common species isolated from cat bite wounds is Pasteurella multocida. In this case report, we discuss a unique case of an intramuscular abscess caused by Bacteroides pyogenes. Antibiotic resistance in Bacteroides species is a growing concern and thus should be treated with caution. We present an 81-year-old female who presented to the emergency department with left calf pain that began 3 weeks prior to the emergency department presentation. She was initially seen by her primary care provider and was prescribed oral Trimethoprim/Sulfamethoxazole and Amoxicillin/Clavulanate. Despite oral antibiotics, she began to have worsening swelling, erythema, and fevers. In the emergency department, the patient's left calf was noticeably erythematous and tender to palpation. Lab work showed a C-reactive protein of 12.4 mg/dl, erythrocyte sedimentation rate of 38 mm/h, and white blood cell count of 15.1. Computed tomography imaging showed an irregularly shaped fluid collection at the junction of the calf musculature and upper aspect of the Achilles tendon. The decision was made to perform an operative incision and debridement on the evening of her presentation. On postoperative day 2, the wound cultures grew positive for both Pasturella multocida and Bacteroides pyogenes. She was subsequently discharged with oral Amoxicillin/Clavulanate 875 mg twice daily for 4 weeks. Further studies can be performed to identify the most efficient ways to isolate and treat this species. This case report emphasizes the importance of ordering both aerobic and anaerobic cultures and aiming antimicrobial therapy against both Pasteurella and anaerobic bacteria.

Molecular evaluation of sheep and goats isolates of Pasteurella multocida and their antibiotic resistance

Pasteurella multocida exists as a commensal in the upper respiratory tracts of livestock, and poultry, and causes a wide variety of diseases in humans and animals. This study aimed to investigate the incidence of P. multocida by bacteriological and molecular characterization in sheep and goats and screening the existence of capsule-specific genes and their antibiotic resistance pattern. Totally, 1650 nasopharyngeal swabs were collected from apparently healthy sheep and goats and 460 lung tissues were collected from slaughtered animals in Fars province, Iran. All samples were cultured and suspected colonies were examined by biochemical tests, antimicrobial assay and polymerase chain reaction (PCR). Among 165 P. multocida (104 sheep and 61 goats) isolates, the capA, capD, and capB genes were amplified in 98, 48, and 12 isolates, respectively. The occurrence of four virulence-associated genes of P. multocida isolates were determined by PCR. Most isolates harbored the toxA (79.40%) and hgbB genes (70.90%) and 59.40% of isolates had the pfhA gene. Almost half of the isolates (46.10%) contained the tbpA gene. According to the current study, P. multocida capsular type A had the most frequency followed by type D. In addition, the high frequency of tbpA, pfhA, toxA, and hgbB genes revealed that these genes are possibly important in the pathogenesis of P. multocida. Oxytetracycline, enrofloxacin, florfenicol, and tilmicosin were the most effective drugs.

Wrist abscess due to drug-resistant Pasteurella multocida

Many cases of cat and dog bites are associated with Pasteurella spp. infections. Antimicrobial therapy usually entails a β-lactam-β-lactamase inhibitor combination such as amoxicillin-clavulanic acid. Drug resistance in human Pasteurella spp. infections has rarely been reported in literature. In this report, we introduce the first documented case of a human Pasteurella spp. infection with resistance to amoxicillin-clavulanic acid. The potential emergence of drug-resistant Pasteurella spp may alter our therapeutic approach to animal bites in the future. This case highlights the need for further epidemiologic studies on Pasteurella spp antibiotic susceptibility patterns in both humans and cats.

An Abrasion, a Prosthetic Shoulder, and a Cat with a Licking Tendency: Case Report and Literature Review of P. multocida Joint Seeding

Pasteurella multocida is a pathogen well known for its zoonotic transmission, most commonly by cats and dogs. When bacteremia ensures from an infection, patients with foreign objects present in their bodies, including prosthetic joints and mesh implants, become vulnerable to seeding. There have been multiple documented cases in which P. multocida bacteremia has resulted in infection of both native and prosthetic joints. Furthermore, cases have been documented in which patients with P. multocida bacteremia have developed meningitis and neurological complications. Here, we present a patient with multiple comorbidities including multifactorial immunocompromise, advanced age, and multiple prosthetic joints who developed prosthetic joint infection and spinal osteomyelitis after the development of Pasteurella bacteremia. Aggressive treatment was undertaken given her risk factors, and a combination of antibiotics and surgery was utilized, with the patient making a full recovery.

Biosynthesis and regulation mechanisms of the Pasteurella multocida capsule

Pasteurella multocida possesses a polysaccharide capsule composed of a viscous surface layer that acts as a critical structural component and virulence factor. Capsular polysaccharides are structurally similar to vertebrate glycosaminoglycans, providing an immunological mechanism for bacterial molecular mimicry, resistance to phagocytosis, and immune evasion during the infection process. In recent years, a series of important research advances have been made in understanding the biosynthesis and regulatory aspects of the P. multocida capsule. This review systematically examines the serogroups, polysaccharide composition and structures, biosynthetic loci and functions, biosynthesis pathways, and expression regulation mechanisms of the P. multocida capsule, supplying a theoretical basis for the molecular pathogenesis of the P. multocida capsule and the future development of capsular polysaccharide vaccines.

Antimicrobial susceptibility and molecular typing of Pasteurella multocida isolated from six provinces in China

Pasteurella multocida (P. multocida) is an important pathogen that causes bovine respiratory disease (BRD) in China and other countries. To investigate the antimicrobial susceptibility of P. multocida isolated from different provinces in China, we analyzed antimicrobial susceptibility phenotypes and pulsed-field gel electrophoresis (PFGE) types of P. multocida; then, we sequenced the complete genome of strain found to be multidrug-resistant. The isolates exhibited resistance to many antimicrobial agents, especially amikacin, sulfamethoxazole, sulfachloropyridazinesodium, macrolides, and fluoroquinolones. Pulsed-field gel electrophoresis analysis showed that a clonal spread of multidrug-resistant isolates occurred in various provinces. All of the isolates carried class I integron.