FLEISCHWIRTSCHAFT international 2/2018
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Fleischwirtschaft <strong>international</strong> 2_<strong>2018</strong><br />
41<br />
Hygiene<br />
Glucuronidase assay for E. coli<br />
The enzyme βglucuronidase<br />
(GUD) is produced by 97% of E. coli<br />
strains and up to 50% of Salmonellae<br />
and Shigellae.Inthe presence of<br />
4methylumberlliferoneβDglucuronide<br />
(MUG), GUD produces a<br />
fluorogenic end product which is<br />
visible in UV light.<br />
Thus, it is arapid and more<br />
efficient way to detect E. coli in<br />
meat; one E.coli cell could be detected<br />
in 20 h. While most positive<br />
reactions occurred in 4h,some<br />
weak GUDpositive strains require<br />
up to 16 hfor reaction. The main<br />
advantage of this method is that<br />
fluorescence appears before gas<br />
production from lactose. Also, that<br />
some Salmonellae and Shigellae are<br />
GUD positive, it does not invalidate<br />
the method since these organisms<br />
are of greater significance in meats<br />
than coliforms.<br />
show MALDITOF MS for the<br />
identification of isolates from<br />
foods and beverages. These reports<br />
evaluate multiple aspects of<br />
the applicability of MALDITOF to<br />
food microbiology and ranged<br />
from the classification of lactic<br />
acid bacteria in fermented meats<br />
to strain identification and characterization<br />
of biogenic amineproducing<br />
bacteria (FERNÁNDEZ<br />
NO et al., 2010).<br />
References<br />
Literature references can be requested<br />
from the corresponding author or the<br />
editorial office, respectively.<br />
Authors’ addresses<br />
Akhilesh K. Verma (corresponding author:<br />
vetakhilesh@rediffmail.com, s/o Uday Raj<br />
Verma, Village &PostRukunpurKasimpur,<br />
TehsilJalalpur District, Ambedkar Nagar,<br />
Uttar Pradesh 224149), Diploma programme<br />
college of Veterinary Science and Animal<br />
husbandry, DUVASU, Mathura 281001, Uttar<br />
Pradesh, India, A. Prajapati, National<br />
Institute of Veterinary Epidemiology and<br />
Disease Informatics, Hebbal, Bengaluru560024,<br />
Karnataka, India, and<br />
Pramila Umaraw, Division of Livestock<br />
Products Technology, Indian Veterinary<br />
Research Institute, Bareilly243122, Uttar<br />
Pradesh, India.<br />
Advertisement<br />
Mass spectrometry<br />
In recent years MatrixAssisted<br />
Laser Desorption IonizationTime<br />
of Flight Mass Spectrometry<br />
(MALDITOF MS) has revolutionized<br />
the routine identification of<br />
bacteria.<br />
This method simultaneously<br />
screens molecular ions and<br />
charged fragments by analyzing<br />
their masstocharge ratios. Comparing<br />
the patterns with the patterns<br />
from known microorganisms<br />
establishes identity.Rapid<br />
and reliable identification of<br />
meatsassociated bacteria is of<br />
crucial importance for the product<br />
quality.Identifications are available<br />
in minutes rather than in days<br />
for the classical methods. Numerous<br />
studies demonstrate, that<br />
MALDITOF MS based identification<br />
is arapid and reliable method<br />
for routine identification of bacteria<br />
(BIZZINI et al., 2010), yeast and<br />
fungi (DHIMAN et al., 2011)from<br />
clinical samples.<br />
Indeed, information concerning<br />
the general performance of the<br />
MALDITOF platform can be<br />
readily evaluated, but the specific<br />
requirements of meat testing<br />
microbial laboratories are generally<br />
not considered. Until now the<br />
focus of MALDITOF MS based<br />
identification of meatsassociated<br />
bacteria has been for food<br />
pathogens like Campylobacter spp.,<br />
Cromobacter spp., Listeria spp.,<br />
Salmonella spp. and Vibrio spp.<br />
(SPARBIER et al., 2012)and their<br />
clinical isolates. Only afew reports
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