Histopathological changes induced in an animal model by potentially pathogenic Enterococcus faecalis strains recovered from ready-to-eat food outlets in Osun State, Nigeria

Figures & data

Table 1 Antibiotic-resistance phenotypes and virulence determinant genes in selected Enterococcus faecalis

Organisms	Antibiotic-resistant phenotypes														Virulence determinant genes
	AMX	TET	COT	ERY	CLX	GEN	CLO	AUG	VAN	LEV	CIP	SPA	NOR	PER	Gel	Esp	CylA	Asa1	Ace
EFT 148	R	R	R	R	R	R	S	R	R	S	R	S	R	R	+	−	−	+	+
EFS 18	S	R	R	R	R	R	R	R	R	S	R	R	R	R	+	−	+	−	−
EFC 12	S	R	R	R	R	R	R	R	R	S	R	S	R	R	+	+	+	+	−

Abbreviations: EFT, fast-food canteen; EFS, school canteen; EFC, Bukataria; AMX, amoxicillin; TET, tetracycline; COT, cotrimoxazole; ERY, erythromycin; CLX, cloxacillin; GEN, gentamicin; CLO, chloramphenicol; AUG, amoxicillin/clavulanic acid; VAN, vancomycin; LEV, levofloxacin; CIP, ciprofloxacin; SPA, sparfloxacin; NOR, norfloxacin; PER, perfloxacin ; R, resistant; s, susceptible.

Figure 1 Development of enterococcemia in albino rats fed orally with Enterococcus faecalis strains with different virulence determinant genes. (◆) EFC 12 with gel⁺, esp⁺, cylA⁺, and asa1⁺ genes, (■) EFT 148 with gel⁺, ace⁺, and asa1⁺ genes and (▲) EFS 18 with gel⁻, esp⁺, and cylA⁺ genes.

Table 2 Hematological changes during enterococcal infection in rats

Parameters	Treatment group
	EFC 12			EFT 148			EFS 18			Control
	W1	W2	W3	W1	W2	W3	W1	W2	W3	W1	W2	W3
WBC (mm^3)	7,800±412.30b	7,830±121.03b	6,120±130.04c	7,110±35.30b	7,220±120.50b	7,012±10.60b	7,610±130.01b	7,635±47.63b	7,060±510.50b	9,228±540.70a	9,240±411.60a	9,306±312.76a
RBC (10^6/mm^3)	7.32±0.13bc	6.02±0.04d	3.12±0.26ef	8.13±0.33a	6.60±0.31cd	3.55±0.26e	7.621±0.21ab	6.501±0.04d	3.31±0.21e	2.10±0.30g	2.30±0.31g	2.38±0.40fg
PCV (%)	38.50±0.40bc	35.30±0.56d	34.01±0.54d	37.4±0.46c	34.50±0.50d	34.03±0.45d	37.21±0.42c	35.23±0.53d	35.31±0.55d	37.80±0.38c	39.50±0.56b	44.4±0.64a
Platelets (10^3/mm^3)	66.21±1.10bc	54.65±34fg	47.00±1.30h	60.11±3.4cdef	57.40±1.30efg	58.00±3.10defg	64.35±1.21bcd	56.41±4.30efg	52.33±1.4gh	61.14±1.05cde	68.12±2.55ab	73.5±1.05a
Hemoglobin (g/dL)	11.60±0.25a	11.10±0.23ab	10.03±0.47abc	11.30±1.10a	11.20±1.02a	10.54±1.54abc	9.35±0.43abc	8.72±1.35bc	8.14±0.43c	8.32±0.42c	9.20±0.55abc	10.3±0.67abc

Note: Means with the same letter along the row are significantly different (P<0.05).

Abbreviations: PCV, packed cell volume; RBC, red blood cells; WBC, white blood cells; W, week.

Figure 2 Pathogenic effects of Enterococcus faecalis strains on experimental animals (magnification 400×). (A) Liver tissue of albino rat (control group) showing normal tissue appearance. (B) Liver tissue of albino rat, fed with EFC 12 (having four virulence genes gel⁺, esp⁺, cylA⁺, and asa1⁺) showing pronounced renal corpuscles and areas of inflammatory changes (arrow). (C) Liver tissue of albino rat fed with EFT 148 (having three virulence genes gel⁺, ace⁺, and asa1⁺) showing necrosis of hepatic cells with pyknotic nuclei, disorganization of hepatic laminae, and dilation of sinusoids (arrow). (D) Liver tissue of albino rats, fed strain of E. faecalis strain EFS 18 (having two virulence genes, ie, gel⁻, esp⁺, and cylA⁺) showing well preserved renal corpuscles and less pronounced areas of inflammatory changes (arrow).