Quantification of Growth of Campylobacter and Extended Spectrum β-Lactamase Producing Bacteria Sheds Light on Black Box of Enrichment Procedures.
Campylobacter is well recognized as the leading cause of bacterial foodborne diarrheal disease worldwide, and is routinely found in meat originating from poultry, sheep, pigs, and cattle. Effective monitoring of Campylobacter contamination is dependent on the availability of reliable detection methods. The method of the International Organization for Standardization for the detection of Campylobacter spp. in food (ISO 10272-1:2006) recommends the use of Bolton broth (BB) as selective enrichment medium, including a pre-enrichment step of 4-6 h at 37°C to revive sublethally damaged cells prior to incubation for 2 days at 41.5°C. Recently the presence of abundantly growing extended spectrum β-lactamase producing Enterobacteriaceae (ESBL bacteria) has become one of the most important factors that interfere with the isolation of Campylobacter, resulting in false-negative detection. However, detailed growth dynamics of Campylobacter and its competitors remain unclear, where these would provide a solid base for further improvement of the enrichment procedure for Campylobacter. Other enrichment broths, such as Preston broth (PB) and BB plus clavulanic acid (BBc) have been suggested to inhibit competitive flora. Therefore, these different broths were used as enrichments to measure the growth kinetics of several strains of Campylobacter jejuni and ESBL bacteria separately, in co-culture and of strains in chicken samples. The maximum cell numbers and often the growth rates of Campylobacter in mixed culture with ESBL bacteria were significantly lower than in single cultures, indicating severe suppression of Campylobacter by ESBL bacteria, also in naturally contaminated samples. PB and BBc successfully diminished ESBL bacteria and might therefore be a better choice as enrichment medium in possibly ESBL-bacteria contaminated samples. The efficacy of a pre-enrichment step in the BB ISO-procedure was not supported for cold-stressed and non-stressed cells. Therefore, omission of this step (4-6 h at 37°C) might be advised to obtain a less troublesome protocol.
Laboratory of Food Microbiology, Wageningen University Wageningen, Netherlands.
Wilma C
WC
Hazeleger
National Institute for Public Health and the Environment Bilthoven, Netherlands.
Wilma F
WF
Jacobs-Reitsma
Laboratory of Food Microbiology, Wageningen University Wageningen, Netherlands.
Heidy M W
HM
den Besten
Bolton broth; ESBL; ISO 10272-1; Preston broth; clavulanic acid; competition; inhibition; pre-enrichment
J Appl Microbiol. 2012 Jul;113(1):200-8
22533742
J Appl Bacteriol. 1993 Feb;74(2):155-63
8444645
Int J Food Microbiol. 2009 Nov 15;135(3):248-53
19786312
Appl Environ Microbiol. 1990 Jun;56(6):1875-81
16348228
Antimicrob Agents Chemother. 2010 Apr;54(4):1623-6
20100875
Foodborne Pathog Dis. 2014 Feb;11(2):104-10
24093132
Lett Appl Microbiol. 2011 Jun;52(6):614-8
21488911
Appl Environ Microbiol. 1998 Oct;64(10):3917-22
9758819
J Clin Microbiol. 1986 Nov;24(5):840-3
3771769
J Appl Microbiol. 2000 Nov;89(5):884-91
11119165
Int J Food Microbiol. 2005 Aug 25;103(2):229-33
15985304
J Clin Pathol. 1982 Apr;35(4):462-7
7042765
J Antimicrob Chemother. 2013 Jan;68(1):60-7
22949623
Int J Food Microbiol. 2013 Apr 1;162(3):308-10
23474610
Infect Genet Evol. 2011 Oct;11(7):1499-504
21689785
J Appl Bacteriol. 1986 Aug;61(2):125-32
3771411
Food Microbiol. 2011 Sep;28(6):1117-23
21645809
Int J Food Microbiol. 2013 Jul 1;165(1):7-10
23685466
Int J Food Microbiol. 2012 Mar 15;154(3):212-4
22260927
Emerg Infect Dis. 2011 Jul;17(7):1216-22
21762575
Int J Food Microbiol. 2015 Oct 1;210:131-5
26119190
Avian Pathol. 2014;43(3):199-208
24666286
Int J Food Microbiol. 2012 Sep 17;159(1):30-8
22938836
Int J Food Microbiol. 2007 Sep 30;118(3):241-9
17719670
Antimicrob Agents Chemother. 1994 Apr;38(4):767-72
8031044
J Appl Bacteriol. 1989 Feb;66(2):119-26
2708169