Antimicrobial Resistance and Virulence Factors of Proteus mirabilis Isolated from Dog with Chronic Otitis Externa

Abstract

Otitis externa is among the most prevalent diseases in dogs. If the underlying cause is not addressed, bacterial reinfection becomes frequent, necessitating antibiotic administration for an extended period of time. Prolonged treatment promotes the emergence of antibiotic-resistant bacteria and increases the risk of their transmission from animals to humans. This study aimed to analyze the antibiotic resistance pattern of the emerging pathogen Proteus mirabilis to identify bacterial virulence and antibiotic selection. Samples were collected from randomly encountered dogs with chronic otitis externa. Thirty-two strains of P. mirabilis were isolated and identified, using MALDI-TOF. The Kirby-Bauer disk diffusion method was used to assess the antibiotic susceptibility of P. mirabilis to 11 antibiotics. The isolates (n = 32) were most resistant to cefazolin (75%), trimethoprim–sulfamethoxazole (72%), chloramphenicol (72%), amoxicillin–clavulanate (63%), ampicillin (59%), cefepime (56%), ciprofloxacin (53%), aztreonam (50%), ceftazidime avibactam (50%), gentamicin (22%), and amikacin (16%). Moreover, 75% of isolates were found to be multidrug-resistant bacteria. P. mirabilis was found to have a high resistance-pattern ratio. Although the exact cause is unknown, continuous antibiotic use is thought to be a major factor. We concluded that antibiotic use must be prudent and selective to prevent antibiotic resistance.

Therapeutic Management of Otitis Externa in Dogs

“…In the present case, the Proteus mirabilis was isolated from the ear of affected dog. The similar findings were also reported by Kwon et al, [12].…”

Microbiological Survey and Evaluation of Antimicrobial Susceptibility Patterns of Microorganisms Obtained from Suspect Cases of Canine Otitis Externa in Gran Canaria, Spain

“…Doxycycline (91.7%), nitrofurantoin (87%) and ampicillin (60%) showed the lowest susceptibility of the antimicrobials tested. A similar level of ampicillin resistance (59%) has also been described for this pathogen in otitis cases [54] and well as in skin infections and abscesses of dogs (50%) [33]. In the same study, performed in Spain, a resistance rate of more than 80% of the isolates to doxycycline was also observed, in agreement with our results.…”

“…Similar results have been observed for gentamicin [ 40 , 53 ]. However, other authors report significantly higher resistance rates for gentamicin (75%) and sulfamethoxazole-trimethoprim (72%), linked in part to the presence of sulfonamide and aminoglycoside specific resistance genes sul 2 and aac(6′)-lb-cr , although the presence of these genes cannot explain by themselves the high degree of resistance observed [ 54 ].…”

Antimicrobial resistance pattern of Uro-Pathogens emphasizing non-lactose fermenting gram negative bacilli

“…This was in line with another study. 23 LF-GNBs represent a challenge to clinicians because of their rising resistance against various antibiotics classes, ultimately leading to multidrug resistance (MDR), extensive drug-resistance (XDR), or even pan-drug resistance (PDR). 24 The resistance in these clinical isolates has developed owing to various mechanisms, such as intrinsic non-susceptibility processes, alterations or through plasmids/integrons during the extended course of therapy although the same treatment was effective primarily.…”