Food Protection Trends - January/February 2015 - 52

Resistance among isolates (%)

100
80
60
40
20
0

E

Cip

Ctx

Mem

Gm

Ak

Ap

Ts

Antibiotic
Figure 1. Percentage resistance of coliform isolates to individual antibiotics.
Cip = ciprofloxacin; Ctx = cefotaxime; Mem = meropenem; Gm = gentamycin;
Ak = amikacin; Ap = ampicillin; Ts = trimethoprim-sulphamethoxasole; E = erythromycin

Furthermore, Y. pseudotuberculosis and S. maltophilia were
both resistant to seven out of the eight antibiotics tested, and
were susceptible to only ciprofloxacin and trimethoprimsulphamethoxasole, respectively. In addition, strains of E.
cloacae showed four antibiotic resistance patterns, whereas
K. pneumoniae showed three patterns. S. liquefaciens, H. alvei
and E. coli had two resistance patterns each (Table 3).
DISCUSSION
Coliforms are ubiquitous in nature, being found in soil
and water environments. However, intestinal tracts of
warm-blooded animals remain the primary reservoirs; thus,
coliforms are usually present in large numbers in the feces
of such animals (18). Species such as E. coli are almost
exclusively of fecal origin. Hence, their presence in foods
can be an indication of fecal contamination. The recovery
rate and variety of coliforms observed in this study may be a
reflection of either poor hygienic conditions in the processing
environment or post-processing contamination by personnel
involved in packaging or handling. Javadi and Safarmashaei
(20) also reported 100% incidence of coliforms in broiler
meat marketed in Iran. An average of 50% in the incidence
of coliforms, belonging mostly to genera identified in this
study, has also been reported in vegetables (8). Saikia and
Joshi (32) similarly noted a high incidence of Enterobacter

52

Food Protection Trends

January/February

aerogenes (100%), Escherichia coli (98%), Klebsiella
pneumoniae (98%), and Proteus (49%) and Citrobacter
(52%) species in raw chicken products in Northeast India.
Furthermore, analysis of microbial contamination of raw
meat products in Abakaliki, Nigeria revealed Escherichia coli
and Klebsiella pneumoniae as the most frequent pathogens
identified in the products (19). Members of the genus
Klebsiella have also been recovered from free-range chicken
samples in the Western Cape Province of South Africa (10).
Thus, the results of the current study, together with reports
from previous researchers, incriminate Klebsiella and E. coli
as the most frequent contaminants of raw broiler portions.
The incidence of Enterobacter cloacae (26.7%) (Table 1)
observed in the current study is higher than the 9% incidence
reported in street foods in Malaysia (16). In addition,
E. cloacae and E. sakazakii have been isolated in infant
formula (13.3 - 20%) and crushed wheat (33.3%),
respectively (33). Although only a few of the genera of
bacteria identified in the current study have been recognized
as common pathogens in humans and animals, all can
become pathogenic under special circumstances.
For instance, strains of E. coli are commonly associated
with enterovirulent urinary tract infections and meningitis
(15). Similarly, Klebsiella pneumoniae, a nosocomial
pathogen associated primarily with respiratory and urinary
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