Biofilm formation and antibiotic sensitivity in Elizabethkingia anophelis

Abstract

Elizabethkingia anophelis has recently gained global attention and is emerging as a cause of life-threatening nosocomial infections. The present study aimed to investigate the association between antimicrobial resistance and the ability to form biofilm among E. anophelis isolated from hospitalized patients in China. Over 10 years, a total of 197 non-duplicate E. anophelis strains were collected. Antibiotic susceptibility was determined by the standard agar dilution method as a reference assay according to the Clinical and Laboratory Standards Institute. The biofilm formation ability was assessed using a culture microtiter plate method, which was determined using a crystal violet assay. Culture plate results were cross-checked by scanning electron microscopy imaging analysis. Among the 197 isolates, all were multidrug-resistant, and 20 were extensively drug-resistant. Clinical E. anophelis showed high resistance to current antibiotics, and 99% of the isolates were resistant to at least seven antibiotics. The resistance rate for aztreonam, ceftazidime, imipenem, meropenem, trimethoprim-sulfamethoxazole, cefepime, and tetracycline was high as 100%, 99%, 99%, 99%, 99%, 95%, and 90%, respectively. However, the isolates exhibited the highest susceptibility to minocycline (100%), doxycycline (96%), and rifampin (94%). The biofilm formation results revealed that all strains could form biofilm. Among them, the proportions of strong, medium, and weak biofilm-forming strains were 41%, 42%, and 17%, respectively. Furthermore, the strains forming strong or moderate biofilm presented a statistically significant higher resistance than the weak formers (p < 0.05), especially for piperacillin, piperacillin-tazobactam, cefepime, amikacin, and ciprofloxacin. Although E. anophelis was notoriously resistant to large antibiotics, minocycline, doxycycline, and rifampin showed potent activity against this pathogen. The data in the present report revealed a positive association between biofilm formation and antibiotic resistance, which will provide a foundation for improved therapeutic strategies against E. anophelis infections in the future.

Central Line-Associated Bloodstream Infection Due to Elizabethkingia anophelis: Case Report and Literature Review on Pediatric Infections

“…The present case was a CLABSI. It has been demonstrated that E. anophelis has the ability to form biofilm that facilitate their establishment in CVCs, complicating treatment [20]. The source of the infection and the route of transmission remain unclear for all cases, except for one of vertical transmission from the mother who had chorioamnionitis to her neonate [11].…”

Elizabethkingia anophelis MSU001 Isolated from Anopheles stephensi: Molecular Characterization and Comparative Genome Analysis

“…This pathway primes proteins for nucleophilic attack by the polyprenol acceptor within the cellular membranes, which may play important roles in epithelial cell adherence, invasion, and colonization of the host during the infection course [ 56 , 57 ]. Antimicrobial susceptibility patterns vary across strains and in the case of clinical isolates, provide an additional layer of difficulty in the selection of appropriate therapeutics [ 23 , 58 , 59 ]. While β-lactamase synthesis remains the most employed defense among Gram-negative bacteria to withstand antibiotics, other resistance mechanisms include the alteration of target drug sites and the implementation of efflux pumps to eliminate the drug from the cell [ 59 ].…”

Microbiological Characterization and Clinical Facets of Elizabethkingia Bloodstream Infections in a Tertiary Care Hospital of Eastern India

“…Several countries have reported the antimicrobial susceptibility of E. anophelis to exhibit resistance to most of the β-lactams, β-lactam combination agents, aminoglycosides, quinolones, and carbapenems irrespective of the testing techniques – Hong Kong (21/21, 100%), China (100% MDR and 20 were extensively drug-resistant, n=197), Taiwan (ciprofloxacin – 89%, cotrimoxazole – 96%) and Lucknow, India (100% resistance to levofloxacin and ciprofloxacin). 6 , 16 , 17 , 24 …”