Biofilm production of Pseudomonas spp. isolates from canine otitis in three different enrichment broths

Abstract

Background -Pseudomonas spp. are commonly isolated from dogs with clinical otitis and have been shown to produce biofilm. There is a paucity of studies demonstrating biofilm growth in veterinary medicine.Hypothesis/objectives -To compare biofilm production of Pseudomonas spp. isolated from dogs with otitis using three different enrichment broths at two different time points. Speciation was performed.Animals -One hundred isolates from 98 dogs with clinical otitis were assessed for biofilm production.Methods and materials -One hundred isolates were assessed for biofilm production using a microtitre plate assay. Biofilm production in Luria-Bertani Broth (LBB), Mueller-Hinton Broth (MHB) and Tryptic Soy Broth (TSB) were assessed after 18 and 24 h of incubation.Results -At 18 h, biofilm production was demonstrated in 87% of LBB, 91% of TSB and 93% of MHB grown isolates. By 24 h, this was 92% of LBB, 96% of TSB and 99% of MHB isolates. Biofilm production was significantly increased after 24 h incubation compared to 18 h. A significant difference was noted in biofilm production between LBB and MHB (P = 0.0349), but not between LBB and TSB (P = 0.3727) or MHB and TSB (P = 0.3687) at 24 h incubation. Two isolates were speciated as P. fluorescens and 98 as P. aeruginosa.Conclusion and clinical importance -Not all enrichment broths were equivalent to one another and 24 h incubation was superior to 18 h. Biofilm production was high in this population of Pseudomonas spp. isolates.

Effectiveness of Tobramycin and Ciprofloxacin Against Bacterial Isolates in Canine Otitis Externa in Uberaba, Minas Gerais

“…In this study, StCN and StCP were susceptible to amoxicillin/clavulanate, probably due to the presence of the inhibitor of beta-lactamase (clavulanate), which may have enhanced the bactericidal effect of this antibiotic (29) . Gram-negative bacteria were resistant to the first-generation cephalosporins, possibly as a result of the narrower spectrum of action of these antibiotics (23) The multi resistance intrinsic of the Pseudomonas aeruginosa (8,30) and the formation of biofilm (31,32) are factors that justify the few options for treatment. Azithromycin has shown variable efficiency against StCP, StCN, Proteus spp.…”

In vitro efficacy of N-acetylcysteine in combination with antimicrobial agents against Pseudomonas aeruginosa in canine otitis externa

“…It acquires antimicrobial resistance through its ability to form biofilms [6,8,22]. According to previous studies, P. aeruginosa isolated from dogs with OE showed various rates of biofilm production, ranging from 40% to 95% [6][7][8]. In this study, 14 P. aeruginosa otic isolates with biofilm formation potency were used to evaluate the antibacterial and antibiofilm ef- ficacy of NAC.…”

“…Pseudomonas aeruginosa is frequently isolated from canines with otitis externa (OE) [1,2]. This pathogen is foreign to the normal otic microflora [3], and many human and mammal studies have provided evidence of biofilm formation by P. aeruginosa [4][5][6][7][8]. A bacterial biofilm is an irreversible structure formed from a bacteria-produced extracellular polymeric matrix.…”

Chemical and microbiological stability of diluted ceftazidime in three different solutions under three storage temperatures over a 28 day period

“…Multiple studies have shown that the presence of TE can enhance the antimicrobial activity of antimicrobials against PA specifically 22–24 . TE also has antibiofilm activity, making it particularly useful for cases of chronic OE due to PA, where biofilm is present in 40–90% of cases 25–27 …”

“…22-24 TE also has antibiofilm activity, making it particularly useful for cases of chronic OE due to PA, where biofilm is present in 40-90% of cases. [25][26][27] With regards to compounded medications, there is currently little oversight, and few enforced regulations and published guidelines, given the multitude of products and formulations that are clinically recommended. According to USP definitions, stability reflects the chemical stability of the active ingredient, physical stability of the product, microbiological stability of the antimicrobial agent, therapeutic stability and toxicological stability.…”