Susceptibility of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) to chlorhexidine digluconate, octenidine dihydrochloride, polyhexanide, PVP-iodine and triclosan in comparison to hospital-acquired MRSA (HA-MRSA) and community-aquired MRSA (CA-MRSA): a standardized comparison

Abstract

Background Recent publications have raised concerns of reduced susceptibilities of clinical bacterial isolates towards biocides. This study presents a comparative investigation of the susceptibility of livestock-associated Methicillin-resistant Staphylococcus aureus (LA-MRSA), hospital-acquired MRSA (HA-MRSA) and community-aquired MRSA (CA-MRSA) to the commonly used antiseptics chlorhexidine (CHX), octenidine (OCT), polyhexanide (PHMB), PVP-iodine (PVP-I) and triclosan (TCX) based on internationally accepted standards. Methods In total, 28 (18 LA-, 5 HA- and 5 CA) genetically characterized MRSA strains representing a broad spectrum of hosts, clonal complexes and spa-types, as well as the reference methicillin-sensitive Staphylococcus aureus (MSSA) strain ATCC 6538, were selected. Minimal inhibitory concentration (MIC) and minimal microbicidal concentration (MBC) were determined in accordance with DIN 58940–7, 58940–8 and DIN EN ISO 20776-1. The microbicidal efficacy was determined in accordance with DIN EN 1040. Results Results from the MIC/MBC and quantitative suspension tests revealed differences between antiseptic substances but not between epidemiological groups of MRSA strains. OCT and PHMB were the most active substances with a minimal MIC of 1 mg/L, followed by CHX (2 mg/L), TCX (32 mg/L) and finally PVP-I (1024 mg/L). The MSSA reference strain showed a tendency to a higher susceptibility compared to the MRSA strains. Conclusions This investigation of the susceptibility of a range of LA-, HA- and CA-MRSA strains using standardized conditions gave no indication that LA-MRSA strains are less susceptible to commonly used antiseptics compared to HA- and CA-MRSA strains.

Phenotypic and Molecular Detection of Antiseptic Resistance Genes among Clinical Staphylococcus aureus Isolates During COVID-19 Pandemic

“…Ignak et al 10 reported that 50% of MRSA and 15% of MSSA had reduced susceptibility to chlorhexidine. Moreover, Dittmann et al 11 reported that 65% of MRSA and 5% of MSSA had decreased sensitivity to chlorhexidine.…”

“…Thus the terms "reduced susceptibility" or "increased tolerance" are better used for pathogens exhibiting an elevated MIC to chlorhexidine. 10,11 When the MIC for chlorhexidine was less than 4 μg/mL, the isolates were deemed susceptible. 3,8 Because chlorhexidine can be used in high quantities without causing toxicity, an increase in MIC values does not imply "resistance."…”

“…Thus, microorganisms with an increased MIC to chlorhexidine are better described as having "reduced susceptibility" or "enhanced tolerance". 10,11…”

Rapid visualization molecular fluorescence detection of methicillin‐resistant Staphylococcus aureus using the multiplex MIRA‐qPCR method

“…[3,5] Over the past 30 years, MRSA infection has become the most common healthcare-associated infection and is highly virulent, aggressive, and drug-resistant. [6,7] MRSA can enter the body through wounds or Pengfei Heng and Bo Shi contributed equally to this work. infected invasive medical devices, resulting in secondary symptoms of infection such as pneumonia, surgical site infections, and bacteremia.…”

Correction to: Susceptibility of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) to chlorhexidine digluconate, octenidine dihydrochloride, polyhexanide, PVP-iodine and triclosan in comparison to hospital-acquired MRSA (HA-MRSA) and community-aquired MRSA (CA-MRSA): a standardized comparison

“…The original article [1] contains an error in Fig. 1 whereby sub-figures 1B, 1C & 1D contain the wrong scale on the x-axis.…”