Presence of antimicrobial resistance in coliform bacteria from hatching broiler eggs with emphasis on ESBL/AmpC-producing bacteria

Figures & data

Table 1. Prevalence of lactose-positive Enterobacteriaceae isolates from broiler hatching eggs by source.

Source	No. of samples analysed	No. of E. coli isolates (%)	No. of E. cloacae isolates (%)	Total (%)
Shell crushed	186	19 (10.2)	3 (1.6)	22 (11.8)
Shell surface	186	8 (4.3)	0	8 (4.3)
Content	186	0	0	0
Total	186 eggs	27 (14.5)	3(1.6)	30 (16.1)

Table 2. Antimicrobial susceptibility percentage with numbers in parenthesis of lactose-positive Enterobacteriaceae isolates from broiler hatching eggs.

Antibiotic	Antimicrobial susceptibility % (N)
	S	I	R
CFTIO	93.3 (28)	0 (0)	6.7 (2)
AM^a	63.0 (17)	3.7 (1)	33.3 (9)
AMC^a	92.6 (25)	0 (0)	7.4 (2)
FFC	96.7 (29)	0 (1)	0 (0)
TET	66.7 (20)	3.3 (1)	30 (9)
FLUM	83.3 (25)	3.3 (1)	13.3 (4)
ENRO	83.3 (25)	3.3 (1)	13.3 (4)
GEN	10.0 (3)	86.7 (26)	3.3 (1)
NEO	76.7 (23)	23.3 (7)	0 (0)
SPECT	100.0 (30)	0 (0)	0 (0)
Nitrofurantoin	96.7 (29)	0 (0)	3.3 (1)
Sulphonamide	66.7 (20)	0 (0)	33.3 (10)
APRA	93.3 (28)	6.7 (2)	0 (0)
TR	73.3 (22)	0 (0)	26.7 (8)

^aE. cloacae was not included to calculate the percentage of susceptibility to this antibiotic.

Table 3. Genetic and phenotypic traits of CFTIO-resistant Enterobacteriaceae obtained from broiler hatching eggs.

Isolate	Farm no.	Egg no.	Source	Identification	ESBL/AmpC phenotype	β-Lactamase genes	Additional resistance phenotype
S12R	2	1	Shell crushed	E. cloacae	AmpC	ACT-39	TET, GEN^a, SUL
S47	2	7	Shell crushed	E. cloacae	ESBL	TEM-1, SHV-12	TET^a
S08R	3	3	Shell surface	E. cloacae	AmpC	Not detected	TET^a, APRA^a
S14R	5	4	Shell crushed	E. cloacae	AmpC	ACT-39	FFC, TET, NIT,
S01	6	2	Shell crushed	E. cloacae	ESBL/AmpC	TEM-1, SHV-12, ACT-39	TET, GEN^a, SUL, TR
S02R	6	2	Shell crushed	E. cloacae	ESBL/AmpC	TEM-1, SHV-12, ACT-39	TET, GEN^a, SUL
S20R	9	2	Shell crushed	E. fergusonii	ESBL	TEM-52	FFC^a, TET, GEN,NEO^a,SUL,TR
S39R	9	10	Shell crushed	E. cloacae	AmpC	ACT-39	/

Note: TET: tetracycline, GEN: gentamicin, SUL: sulphonamide, APRA: ampramycin, NIT: nitrofurantoine, NEO: neomycin, TR: trimethoprim, FFC: florfenicol.

^aStrain intermediately susceptible to this antibiotic.

Figure 1. (a) MIC of the recovered isolates from broiler hatching eggs determined for GLU per genus. (b) MIC of the recovered isolates from broiler hatching eggs determined for H₂O₂ per genus. (c) MIC of the recovered isolates from broiler hatching eggs determined for FOR per genus.