Chloroxylenol- and triclosan-tolerant bacteria from industrial sources

Abstract

Potential development of bacterial tolerance to biocides in the industrial environment is examined in this study. Bacteria tolerant to the phenolic-type agent para-chloro-meta-xylenol (PCMX) and the bis-phenol 2,4,4'-trichloro-2'-hydroxydiphenylether (triclosan) were isolated from industrial sources and identified. Minimum inhibitory concentrations (MICs) were determined and compared with those of culture collection (standard) strains. Of around 100 isolates originally obtained, most were naturally tolerant species such as Pseudomonas spp., or showed low tolerance levels. PCMX-tolerant isolates of Pseudomonas stutzeri and triclosan-tolerant isolates of Citrobacter freundii and Acinetobacter johnsonii were retained for further study. Of these, only P. stutzeri and A. johnsonii showed elevated tolerance compared with the standard strains. There was no evidence of tolerance to the other biocide except for Pseudomonas aeruginosa (an intrinsically tolerant microorganism), and tolerances were stable in the absence of selective pressure except for A. johnsonii. Attempts to select or generate increased tolerance in the standard strains were unsuccessful. High tolerances in terms of MIC were not reflected in terms of lethal effects. This study did not produce any evidence suggesting that the presence of residual biocide concentrations in the industrial environment promotes the emergence of bacterial tolerance for them.

Antibacterial Cleaning Products and Drug Resistance

“…One recent cross-sectional study ( 17 ) reported a higher prevalence of decreased susceptibility to triclosan among methicillin-resistant S. epidermidis compared to methicillin-sensitive S. epidermidis clinical isolates. The findings reported in other cross-sectional studies have mainly examined environmental and clinical isolates of bacteria, and the correlations reported have been inconsistent ( 11 , 13 , 18 – 20 ). …”

Antimicrobial Resistance on Farms: A Review Including Biosecurity and the Potential Role of Disinfectants in Resistance Selection

“…Field studies have provided some evidence for reduced susceptibility to certain disinfectants among bacterial isolates from hatcheries (where disinfectants are applied daily, usually at sublethal concentrations) and biocide manufacturing plants (Lear, Maillard, Dettmar, Goddard, & Russell, 2002;Willinghan, Sander, Thayer, & Wilson, 1996). However, other studies (examining farm bacteria) have failed to find significant evidence of such associations (Aarestrup & Hasman, 2004;Martin & Maris, 1995).…”

Occurrence and distribution pattern of acidic pharmaceuticals in surface water, wastewater, and sediment of the Msunduzi River, Kwazulu‐Natal, South Africa

“…There are growing concerns over the toxicological effects of the exposure of these compounds to humans and the ecosystem . The identified risks include development of microbial resistance to antibiotics and feminization or masculinization of aquatic organisms on exposure to hormones , among others. The environmental compartments that have been studied include wastewater treatment plant (WWTP) influents, effluents, and receiving surface water ; sediments ; biosolids and waste from confined animal farms ; and groundwater and drinking water .…”