The Importance of Endospore-Forming Bacteria Originating from Soil for Contamination of Industrial Food Processing

Table 2

Recent data on presence of B. cereus, C. tyrobutyricum, or butyric acid spores, C. botulinum, C. perfringens, C. estertheticum, or C. gasigenes in soil, agricultural samples, or raw milk.

Main sample category	Specific microorganism(s) (if indicated)	Sample type	Number of samples	Total aerobic or anaerobic		Specific spore prevalence and count			Reference
		(if further indicated)		spore count (log cfu/g or mL)		(log cfu/g or mL, unless otherwise indicated)
				Average^a or median^c	Range^b	Prevalence (%)	Average^a or median^c	Range^b
Soil	B. cereus	Farm soil	38^i–14^h				4.9^a,i–5.0^a,h	4.1^i–6.0^i	[9]
	Butyric acid spores	Farm soil	59^j				4.2^a,j	3.2–4.9^j	[10]
	C. botulinum	Apiary soil	235			31	2.0/kg^a	1.7–3.0/kg	[11]
	Botulinum-toxin-	Virgin soil^k	661			16.3			[12]
	producing clostridia	Nonvirgin soil^l	1348			27.0
	C. perfringens	Soil various sources	502			75.1		0–3.5	[13]
	C. estertheticum	Soil around abattoir				2.1^m–14.6^n			[14]
	C. gasigenes	Soil around abattoir				10.4^m,n
	Anaerobic spores	Farm soil		4.0^c	2.0–5.2				[15]
Feed	B. cereus	Silage	66^g–19^h				2.2^a,g–2.8^a,k	<1.0^g–3.7^h	[9]
	Butyric acid spores	Mixed silage	122^j				4.2^a,j	<1.5^j–6.0^j	[10]
	Anaerobic spores	Grass silage		<2.0^c	<2.0–6.89^d				[15]
	Anaerobic spores	Maize silage		4.45^c	<2.0–4.69				[15]
Cows’ faeces	Aerobic spores				4.7^b,e–6.2^b,f				[16]
	B. cereus		66^g–14^h				2.0^a,g–2.5^a,h	1.0^g–3.8^h	[9]
	Butyric acid spores		141^j				4.7^a,j	<1.5^j–7.0^j	[10]
Bedding	B. cereus	Used bedding	66^g–38^i				2.7^a,g–3.1^a,i	1.0^g–4.0^i	[9]
	B. cereus	Used deep-straw bedding	4				6.4^a		[17]
	B. cereus	Used sand bedding	2				2.3^a		[17]
	B. cereus	Used sawdust bedding	4				4.3^a		[17]
	B. cereus	Used straw bedding	4				3.9^a		[17]
	Butyric acid spores	Bedding material	113^j				4.5^a,j	<1.5^j–6.0^j	[10]
Raw milk	Aerobic spores	Raw bulk tank milk	18	3.74^a					[18]
	B. cereus		66^g–38^i				1.0^a,g–1.5^a,i/litre	<1.0^g–2.9^i/litre	[9]
	Butyric acid spores	Farm tank milk	142^j				2.7^a,j/litre	<1.5^j–4.2^j/litre	[10]

^aaverage concentration as indicated in table; ^bminimum and maximum value; ^cmedian concentration as indicated in table; ^dextreme value; ^eprior to feedlotting; ^fat day 76 of feedlotting; ^gsamples analysed for B. cereus count for cows housed in barn all day in housing period (November–April); ^hsamples analysed for B. cereus count for cows at pasture 24 h per day during grazing period (May to October); ⁱsamples analysed for B. cereus count for cows at pasture during daytime during grazing period (May to October); ^jsamples collected between January and December on 24 farms; ^ksoils not changed by people; ^lsoils changed by people (cultivated, urbanized, industrialized); ^mculture based detection; ⁿDNA based detection.