Prevalence, antibiotic profile, virulence determinants, ESBLs, and non-β-lactam encoding genes of MDR Proteus spp. isolated from infected dogs

Zoonotic relevance of multidrug-resistant bacteria in parrots with respiratory illness

Nowadays, research attention is paid to the investigation of bacterial pathogens in the cloaca of parrots rather than the nasal niche, which is largely ignored. Therefore, this study aimed to investigate the nasal carriage of multidrug-resistant bacteria with zoonotic potential in parrots suffering from respiratory illness. Nasal swabs were collected from 75 sick parrots with respiratory illness, and they were subjected to microbiological isolation and identification, followed by antimicrobial susceptibility testing. Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Staphylococcus aureus were isolated with a prevalence rate of 36%, 32%, 26.7%, and 9.3%, respectively, while one isolate (1.3%) of Staphylococcus pseudointermedius, Staphylococcus simulans, Staphylococcus sciuri, and Enterococcus faecalis was identified. E. coli, K. pneumoniae, and P. mirabilis were investigated for ESBL genes, Staphylococcus species for the mecA gene, followed by SCCmec typing, and E. faecalis for the vanA and vanB genes. Regarding beta-lactamase-encoding genes, blaTEM (97.6%), blaSHV (48.8%), and blaCTX-M (39%) gene families were detected, while blaOXA was not found. Sequencing of blaCTX-M in one strain of E. coli, K. pneumoniae, and P. mirabilis revealed blaCTX-M-15. The mecA was determined in three S. aureus and one S. sciuri strain, and the SCCmec typing of three MRSA isolates yielded type V, whereas type I in S. sciuri. Only the vanA gene was recognized in the E. faecalis strain. Moreover, 67.1% of bacterial isolates exhibited multidrug resistance. These findings highlight the potential role of parrots in the transmission of multidrug-resistant zoonotic bacteria, which may pose a threat to human contacts.

Antimicrobial Susceptibility Patterns of Bacteria Associated With Hepatobiliary Disease in Dogs and Cats (2010-2019)

BACKGROUND

Description of antibiotic susceptibility of isolates from dogs and cats with hepatobiliary disease is limited.

OBJECTIVES

To describe antibiotic susceptibility patterns of bacteria associated with hepatobiliary disease in dogs and cats over a 10 year-period.

ANIMALS

Three hundred nine dogs and cats.

METHODS

Bacterial species and antibiotic susceptibility data from positive bile and liver tissue cultures were reviewed from both a Veterinary Teaching Hospital and a private laboratory. Prevalence of multidrug-resistant (MDR) bacteria was assessed, along with its association with previous antibiotic administration.

RESULTS

A total of 343 bacterial isolates were included from 310 cultures. Monobacterial cultures were more frequent (91%, 283/310). Gram-negative bacteria were predominant (67%, 227/340), with Escherichia coli (49%, 136/340), Staphylococcus spp. (14%, 47/340), and Enterococcus spp. (10%, 34/340) being the most prevalent isolates. Resistance of gram-negative bacteria were: amoxicillin-clavulanic acid (33%, 70/214), aminopenicillins (47%, 96/205), and fluoroquinolones (16%, 67/417); for gram-positive bacteria: amoxicillin-clavulanic acid (12%, 5/41), aminopenicillins (16%, 11/67), and fluoroquinolones (17%, 35/111). Resistance was significantly higher for aminopenicillins, first-generation cephalosporins, TMPS, tetracyclines, and fluoroquinolones during 2010-2014 compared to 2015-2019. MDR isolates comprised 40% (135/430) of all isolates, 30% (41/136) of E. coli, and 68% (23/34) of Enterococcus spp. A significantly higher incidence of MDR bacteria was observed in animals with previous antibiotic treatment (81%, 17/21) compared to those without (30%, 22/75; p < 0.001).

CONCLUSION AND CLINICAL IMPORTANCE

Conducting culture and sensitivity testing remains crucial in dogs and cats suspected of hepatobiliary infection to ensure effective treatment.

Phage P2-71 against multi-drug resistant Proteus mirabilis: isolation, characterization, and non-antibiotic antimicrobial potential

Proteus mirabilis, a prevalent urinary tract pathogen and formidable biofilm producer, especially in Catheter-Associated Urinary Tract Infection, has seen a worrying rise in multidrug-resistant (MDR) strains. This upsurge calls for innovative approaches in infection control, beyond traditional antibiotics. Our research introduces bacteriophage (phage) therapy as a novel non-antibiotic strategy to combat these drug-resistant infections. We isolated P2-71, a lytic phage derived from canine feces, demonstrating potent activity against MDR P. mirabilis strains. P2-71 showcases a notably brief 10-minute latent period and a significant burst size of 228 particles per infected bacterium, ensuring rapid bacterial clearance. The phage maintains stability over a broad temperature range of 30-50°C and within a pH spectrum of 4-11, highlighting its resilience in various environmental conditions. Our host range assessment solidifies its potential against diverse MDR P. mirabilis strains. Through killing curve analysis, P2-71's effectiveness was validated at various MOI levels against P. mirabilis 37, highlighting its versatility. We extended our research to examine P2-71's stability and bactericidal kinetics in artificial urine, affirming its potential for clinical application. A detailed genomic analysis reveals P2-71's complex genetic makeup, including genes essential for morphogenesis, lysis, and DNA modification, which are crucial for its therapeutic action. This study not only furthers the understanding of phage therapy as a promising non-antibiotic antimicrobial but also underscores its critical role in combating emerging MDR infections in both veterinary and public health contexts.

Combined Anti-Bacterial Actions of Lincomycin and Freshly Prepared Silver Nanoparticles: Overcoming the Resistance to Antibiotics and Enhancement of the Bioactivity

Bacterial drug resistance to antibiotics is growing globally at unprecedented levels, and strategies to overcome treatment deficiencies are continuously developing. In our approach, we utilized metal nanoparticles, silver nanoparticles (AgNPs), known for their wide spread and significant anti-bacterial actions, and the high-dose regimen of lincosamide antibiotic, lincomycin, to demonstrate the efficacy of the combined delivery concept in combating the bacterial resistance. The anti-bacterial actions of the AgNPs and the lincomycin as single entities and as part of the combined mixture of the AgNPs-lincomycin showed improved anti-bacterial biological activity in the Bacillus cereus and Proteus mirabilis microorganisms in comparison to the AgNPs and lincomycin alone. The comparison of the anti-biofilm formation tendency, minimum bactericidal concentration (MBC), and minimum inhibitory concentration (MIC) suggested additive effects of the AgNPs and lincomycin combination co-delivery. The AgNPs' MIC at 100 μg/mL and MBC at 100 μg/mL for both Bacillus cereus and Proteus mirabilis, respectively, together with the AgNPs-lincomycin mixture MIC at 100 + 12.5 μg/mL for Bacillus cereus and 50 + 12.5 μg/mL for Proteus mirabilis, confirmed the efficacy of the mixture. The growth curve test showed that the AgNPs required 90 min to kill both bacterial isolates. The freshly prepared and well-characterized AgNPs, important for the antioxidant activity levels of the AgNPs material, showed radical scavenging potential that increased with the increasing concentrations. The DPPH's best activity concentration, 100 μg/mL, which is also the best concentration exhibiting the highest anti-bacterial zone inhibition, was chosen for evaluating the combined effects of the antibiotic, lincomycin, and the AgNPs. Plausible genotoxic effects and the roles of AgNPs were observed through decreased Bla gene expressions in the Bacillus cereus and Bla_CTX-M-15 gene expressions in the Proteus mirabilis.