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Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride

View Article: PubMed Central - PubMed

ABSTRACT

Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC) bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK) cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl), dodecyldimethylbenzylammonium chloride (C12BDMA-Cl), decyldimethylbenzylammonium chloride (C10BDMA-Cl), hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB) to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread.

No MeSH data available.


Effects of the efflux pump inhibitor CCCP on the growth of B. cenocepacia AU1054 in 1/10-diluted TSB medium containing 60 µg/ml C12BDMA-Cl.
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fig1: Effects of the efflux pump inhibitor CCCP on the growth of B. cenocepacia AU1054 in 1/10-diluted TSB medium containing 60 µg/ml C12BDMA-Cl.

Mentions: An efflux experiment was performed to determine whether BCC bacteria were more resistant to C12BDMA-Cl in the presence or absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP) because of an active efflux mechanism. B. cenocepacia AU1054 grew well in 1/10-diluted tryptic soy broth (TSB) supplemented with CCCP only and reached a level almost equal to that in the medium without CCCP. The strain showed a lower rate of growth in the first 4 days of incubation in the medium supplemented with CCCP and 60 µg/ml C12BDMA-Cl than in the medium without CCCP. This demonstrated that CCCP increased the sensitivity of B. cenocepacia AU1054 to C12BDMA-Cl in 1/10-diluted TSB (Fig. 1).


Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride
Effects of the efflux pump inhibitor CCCP on the growth of B. cenocepacia AU1054 in 1/10-diluted TSB medium containing 60 µg/ml C12BDMA-Cl.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120141&req=5

fig1: Effects of the efflux pump inhibitor CCCP on the growth of B. cenocepacia AU1054 in 1/10-diluted TSB medium containing 60 µg/ml C12BDMA-Cl.
Mentions: An efflux experiment was performed to determine whether BCC bacteria were more resistant to C12BDMA-Cl in the presence or absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP) because of an active efflux mechanism. B. cenocepacia AU1054 grew well in 1/10-diluted tryptic soy broth (TSB) supplemented with CCCP only and reached a level almost equal to that in the medium without CCCP. The strain showed a lower rate of growth in the first 4 days of incubation in the medium supplemented with CCCP and 60 µg/ml C12BDMA-Cl than in the medium without CCCP. This demonstrated that CCCP increased the sensitivity of B. cenocepacia AU1054 to C12BDMA-Cl in 1/10-diluted TSB (Fig. 1).

View Article: PubMed Central - PubMed

ABSTRACT

Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC) bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK) cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl), dodecyldimethylbenzylammonium chloride (C12BDMA-Cl), decyldimethylbenzylammonium chloride (C10BDMA-Cl), hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB) to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread.

No MeSH data available.