Household Antibacterial Product Use May Promote Microbial Resistance

[Guest guest]

sorry i don't know how to submit the link wihtout it being thru my medscape

access......

Household Antibacterial Product Use May Promote Microbial Resistance

Laurie Barclay, MD

July 3, 2008 - Antibacterial product use may lead

to decreased susceptibility to other

antibacterial ingredients and antibiotic

resistance in the home, according to the results

of a study reported at the 2008 Annual Conference

on Antimicrobial Resistance held in Bethesda,

land.

" Quaternary ammonium compounds (QACs), such as

benzalkonium chloride [bZK], are broad-spectrum

antimicrobials that have been widely used for

decades to disinfect environmental surfaces in

clinical and industrial settings, " presenter and

lead author Aiello, PhD, MS, an assistant

professor of epidemiology at the University of

Michigan School of Public Health in Ann Arbor,

told Medscape Infectious Diseases. " With

increasing use of cleaning and hygiene products

containing QACs in the home, there is a valid

public health concern that biocide resistance may

emerge in the community environment, " she said.

" Antibacterial consumer products leave residues

on home surfaces, exposing bacterial species to

low levels of the agent and creating conditions

favorable for development of resistance to both

biocides and antibiotics. " Dr. Aiello said.

" Currently, reports examining the relationships

between biocide use and bacterial resistance

among isolates from the community setting are

limited. The purposes of the present study were

to assess the effect of antibacterial product

usage in the home environment on the

susceptibility to QACs and to examine the

possible correlation between QACs and antibiotic

resistance among bacterial isolates sampled from

the hands of study participants. "

In this study, 238 households were randomly

assigned to use either antibacterial or

non-antibacterial cleaning products. At baseline

and 1 year later, 645 bacterial isolates,

including gram-negative and staphylococcal

species, were isolated from hands of participants

and tested for minimum inhibitory concentrations

to BZK, triclosan, and several antibiotics.

Sensitivity testing was performed for all

gram-negative bacteria against gentamicin,

imipenem, and ciprofloxacin; for Acinetobacter

baumannii and A lwoffii against amikacin and

ticarcillin/clavulanate; for Enterobacter

agglomerans and E cloacae against

trimethoprim/sulfamethoxazole; for Klebsiella

pneumonia against trimethoprim/sulfamethoxazole,

piperacillin/tazobactam, and ceftriaxone; for

Pseudomonas fluorescens/putida against

piperacillin/tazobactam and ceftazidime; and for

staphylococcal species against oxacillin for

methicillin resistance.

The relationship between BZK, triclosan, and

antibiotic resistance among bacterial species was

determined using logistic regressions with

generalized estimating equations.

For all species combined, there were no

significant differences between assigned product

use and BZK susceptibility. After 1 year,

however, for all species combined, there was an

association between decreased susceptibility to

BZK and triclosan (odds ratio [OR], 2.18; 95%

confidence interval [CI], 1.44 - 3.29) and

between decreased susceptibility to BZK and

antibiotic resistance to a combination of several

antibiotics (OR, 2.45; 95% CI, 1.38 - 4.36).

" Our study reports, for the first time, a

significant relationship between use of a common

antibacterial cleaning agent ([bZK]) and

cross-resistance with antibiotics and another

antibacterial ingredient (triclosan) in the

household setting, " Dr. Aiello said. " The results

of our study suggest that the growing concern

over the emergence of cross-resistance between

biocides used in the household and clinically

used antibiotics is warranted. "

A study limitation noted by Dr. Aiello is that

the concentrations of biocide tested in the

laboratory were much lower than concentrations

recommended for home use. However, there have

been reports in some clinical settings of

diluting these products, although whether this

practice occurs in the household setting is

unclear.

" Diluting could lead to lower levels of the

biocide, which may be an important factor in

selecting for antibiotic resistance, " Dr. Aiello

said. " There has been little research on how

effective these surface and floor biocides are

for reducing infectious illnesses in the home

environment. Given that there may be a potential

risk related to antibiotic resistance, we need to

conduct further research on the potential

benefits to accurately define the public health

importance of these products. "

Medscape Infectious Diseases asked

, PhD, an assistant professor and codirector

of the College Center for Hygiene and

Health in Home and Community in Boston,

Massachusetts, to review the strengths and

limitations of this study. Dr. was not

involved with this research.

" This is an extensive study conducted over a

substantial time period that adds another

important piece of information to the growing

body of knowledge on the relationship between

BZK, triclosan and the potential for antibiotic

resistance, " Dr. said. " If the products

tested are household cleaning products (as

opposed to personal care products), it would have

been useful to have tested bacterial cultures

from household surfaces as well as from hands.

Also, it is not clear whether or not other

factors that can influence antibiotic resistance

patterns were accounted for, such as skin

condition and household antibiotic usage, as well

as householder occupations, presence of pets,

etc. "

In light of growing concerns about antibiotic

resistance, and the need to balance these

concerns against protection of an increasing

population of vulnerable individuals from

community-acquired infections, Dr.

recommends better education and dissemination of

information on appropriate hygiene and cleaning

practices for homes, daycares, schools,

workplaces, and other settings.

" We need to be extremely vigilant in protecting

the remaining, limited number of effective

antibiotics, " Dr. concluded. " This includes

careful monitoring of antibacterial products, as

well as practicing responsible antibiotic

prescribing in both human and animal medicine and

animal husbandry. At the same time, it is very

important to encourage effective personal hygiene

behaviors, as well as household and community

cleaning and sanitation practices, as a means of

preventing community-acquired infections and thus

reducing the reliance on antibiotics - it's the

old adage of 'prevention is better than cure.' "

Dr. Aiello and Dr. have disclosed no relevant financial relationships.

2008 Annual Conference on Antimicrobial

Resistance: Abstract S5. June 23-25, 2008.

" Medical research has made such progress, that there are practically no

healthy people any more. " – Aldous Huxley

" ....Perfume to you, to me is excrement. " - Pope

I will not have my life narrowed down

.. I will not bow down to somebody else's whim or to someone else's

ignorance. -bell hooks

**************Gas prices getting you down? Search AOL Autos for

fuel-efficient used cars.

(http://autos.aol.com/used?ncid=aolaut00050000000007)

[Guest guest]

and this too....

http://www.reuters.com/article/healthNews/idUSL0383329520080603

llaci