Question

Which bacterium can contaminate then grow inside canned foods?

a) Listeria monocytogenes

b) Corneybacterium diptheriae

c) Clostridium botulinium

d) Staphylococcus aureus

Answer 1

Clostridium botulinum ( option c ) can contaminate then grow inside canned foods .

[ Clostridium botulinum is an anaerobic , rod shaped bacterium that produce botulism diseases by its neurotoxin botulinum . botulism is a paralytic diseases or nerve diseases which is commonly transmitted from canned food . this bacteria produce spore in canned food especially moist food , low - acid food ( pH above 4.6 such as meat , vegetables corn etc ) and the spore produce vegetative cells which mults in anaerobic condition ( canned food contain 0 - 2% oxygen which is ideal for clostridium botulinum growth .canned food's temperature and low oxygen level  help in growth and multiplication of clostridium botulinum inside canned food .  )

therfore option c is right option .

option a listeria monocytogenes is a gram positive bacteria and is also a foodborne pathogen which causes listeriosis . . it can grow in anarobic condition and also in low temperature as low as 0 degree celcius , which helps it to grow in refrigerated food .and canned food does not need refrigeretion usually , as canned food are self stable . canned food  has a low chance of spreading listoriosis hence it is not right option . . it contaminates through vegetables , soil and water and raw milk and underprocessed food ( canned food are not underprocessed usually ) . listeria attack usually pregnant woman , old person , low immunity person .

option b Corneybacterium diptheriae is a rod shaped , pathogenic bacteria which causes diptheria . it transmited from person to person especially through respiratory droplets during coughing , sneezing . corneybacterium diptheriae are not transmitted through canned food . hence this is not the correct option .

option d , Staphylococcus aureus is a pathogenic bacteria and are one of the major cause of food poisioning it can poisioned meat , milk ,dairy products , bakery product , egg products etc . with its toxin . this bacteria is carried by skin and nose of some people therefore it is transmitted by food workers mainly . it can be killed by proper coocking or high heat hence there is a low chance of growing in canned food as canned food trated with high heat . hence option d is also wrong . but the toxin remains in the food after coocking .