Antimicrobial resistance and virulent nature of Escherichia coli from an abattoir and retail market in Ghana

Abstract

This study investigated virulence - associated resistance genes and phylogenetic analysis of Escherichia coli (E. coli) isolated from various meat types in Ghana. The prevalence of virulence genes detected among E. coli isolates were 71.4%, 24.5%, 20.4%, 18.4%, and 4.1% for ibeA, iutA, KpsMTII, papGIII, and sfa, respectively. The E. coli strains belonged to four major phylogenetic groups; group A (14.3%), group C (34.7%), group D (30.8%), and group F (6.1%). E. coli resistance to relevant antibiotics ranged between 12.5% and 85.7%. The prevalent resistance gene was tet A (16.3%), tet B (4.08%), and floR (4.08%). One E. coli isolate from local chicken harboured blaCTX-M and another from local guinea fowl meat carried blaTEM. Virulence and resistance genes occurred (P < 0.05) frequently in chicken meat and guinea fowl than other meat types. This study revealed that some meat types in Ghana contaminated with E. coli strains harboured several virulence and resistance genes. This may pose a serious threat to public health. Therefore, continuous surveillance of E. coli strains with virulence/resistance genes in different meat types is warranted. Furthermore, meats in Ghana should be well cooked prior to consumption.

Keywords:

• Escherichia coli
• Ghana
• meats
• phylogenetic groups
• virulence gene

REVIEWING EDITOR:

• Pedro González-Redondo, University of Seville, Spain

SUBJECTS:

• Science
• Environment & Agriculture
• Plant & Animal Ecology
• Food Science & Technology
• Food Additives & Ingredients
• Medicine
• Health and Social Care
• Allied Health

1. Introduction

Meats are major source of essential amino acids to humans and these include arginine, cysteine, leucine, lysine, methionine, phenylalanine, and tryptophan, among others which are absent in plant proteins. They also contain minerals like iron, zinc, phosphorus, magnesium, sodium, potassium and calcium (Ahmad et al., 2018). According to Wrona (2021), vitamin D3, vitamin B12, taurine, creatine, carnitine, carnosine, heme iron, and docosahexaenoic acid are top nutrients found in appreciable quantities only in meats. Notwithstanding the significance of meat to mankind, they can be sources of diverse foodborne pathogens responsible for foodborne infections which at times can be fatal. Several studies have reported on the contamination of meat by Escherichia coli (E. coli) strains (Abdissa et al., 2017; Adzitey, 2015; Adzitey et al., 2020). For instance, Rahimi et al. (2012) reported that 4.7% of meat samples were contaminated by Escherichia coli, while Albarri et al. (2017) reported a contamination rate of 56.1% meat samples by E. coli. There is also evidence of the involvement of E. coli from meat sources causing foodborne infections, hospitalizations and death (Centers for Disease Control and Prevention (CDC), 2018), and also CDC (2019) reported an outbreak of E. coli infections from ground beef which resulted in six hospitalizations, one case of hemolytic uremic syndrome. In recent years, research investigators have hypothesized that food, including meat and meat products can be reservoirs for a vast array of virulence attributes associated with extraintestinal infections and could play a significant role in the spread of extraintestinal pathogenic E. coli strains (ExPEC) (Jakobsen et al., 2011; Johnson et al., 2007; Xia et al., 2011). ExPEC are bacterial strains with pathogenic potentials and inhabitants of the normal human intestinal fora. Members of the ExPEC group comprise of uropathogenic E. coli (UPEC), neonatal meningitis E. coli (NMEC), sepsis-associated E. coli (SEPEC), and the avian pathogenic E. coli (APEC) (Kathayat et al., 2021; Rybak et al., 2022). Several virulence attributes associated to adhesins, toxins, iron acquisition factors, lipopolysaccharides, polysaccharide capsules, and invasins have been found in ExPEC and coded on pathogenicity islands (PAIs) and plasmids (Krawczyk et al., 2017; Sarowska et al., 2019). These virulence traits enable ExPEC bacterial strains to invade, colonize and cause extraintestinal infections in poultry, livestock, and human (Krawczyk et al., 2017; Vounba et al., 2019).

According to Clermont et al. (2013), E. coli strains can be delineated into seven phylogroups including A, B1, B2, C, D, E, and F, however the eighth group is known as E. coli clade1 (Clermont et al., 2013; Ewers et al., 2009; Michalik et al., 2018). Furthermore, virulence determinants exhibit critical role in this categorization. Phylogroup A or B1 are members of commensal E. coli with propensity of colonization of the gastrointestinal mucosa, while those with pathogenic attributes of intestinal infection belong to A, B1 and D group. However, majority of ExPEC strains are represented by group B2 and D (Krawczyk et al., 2017; Michalik et al., 2018). More recently, the increasing dissemination of antibiotic resistance among human, food animals and environment has become one of the most pertinent health challenges (Murray et al., 2022). The National Antimicrobial Resistance Monitoring System (NARMS) study of E. coli reported that over 20% of the E. coli isolates from chicken and turkey products, pork chops (8.3%), and ground beef (3.4%) met the molecular requirement to be considered as ExPEC (Xia et al., 2011). Furthermore, majority of these ExPEC isolates were multidrug-resistance and were linked to the phylogroups (B2 and D), which is similar to those frequently involved with extraintestinal human diseases (Kirtikliene et al., 2022; Xia et al., 2011).

Hitherto, studies conducted on foodborne pathogens associated with meats in Ghana have concentrated much on isolation and antibiotic susceptibility, however there has been limited work on a comprehensive study of ExPEC phylogroups and virulence determinants among livestock and poultry. To the best of our knowledge, this is the first time E. coli recovered from various meat samples in Ghana have been characterized for their virulence genes and phylogenetic groupings using TSPE4C2, chuA, yjaA, and arpA as molecular markers.

2. Methods

2.1. Escherichia coli strains

A total of 49 E. coli isolates previously isolated from various meat samples from Ghana were used. They were isolated from 225 meat samples comprising of beef (n = 45), chevon (n = 45), mutton (n = 45), chicken (n = 45), and guinea fowl (n = 45) from Tamale market and 150 meat samples comprising of beef liver (n = 50), beef kidneys (n = 50), and beef muscle from Wa Abattoir. Although equal number (n = 8 each) of E. coli isolates were projected, only 49 were recovered from storage and used for this study. Supplementary Table 1 provides some details of the E. coli isolates examined. The isolates were recovered on Trypticase Soya Agar (Oxoid Limited, Basingstoke, UK) and incubated at 37 °C for 18–24 hours. Escherichia coli isolates were further confirmed using the Matrix-assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) mass spectrometry (Bruker Daltonics, Germany).

2.2. Antibiotic susceptibility testing

The antibiogram of 49 E. coli isolates were screened by the Kirby-Bauer disc diffusion method using Mueller-Hinton agar (Oxoid, UK) as culture medium as previously described by Clinical and Laboratory Standards Institute (CLSI) (2022) guidelines. Six commercially available antibiotics utilized were ciprofloxacin (5 μg), chloramphenicol (30 μg), ceftriaxone (30 μg), gentamicin (10 μg), sulphamethoxazole-trimethoprim (22 μg), and tetracycline (30 μg) (Oxoid, UK). The measured zone of inhibition was interpreted as per sensitive (S), intermediate (I), or resistant (R) based on CLSI (2022) break points. E. coli isolates indicative of resistant to three or more antibiotic groups was recognized as multidrug-resistant (MDR) (Magiorakos et al., 2012). E. coli ATCC 25922 was utilized as quality control strain.

2.3. Phenotypic confirmatory test of ESBL production

All Escherichia coli isolates with reduced susceptibility to 3rd generation cephalosporin (ceftriaxone) were subjected to Extended Spectrum Beta-Lactamase (ESBLs) confirmatory test. The phenotypic confirmatory disc diffusion test was employed as recommended by CLSI (2022) guidelines. Briefly, 0.5 MacFarland suspension of an overnight culture of test organisms was inoculated onto Mueller-Hinton agar with a sterile swab, followed by the application of a combination of cefotaxime (30 μg), cefotaxime plus clavulanic acid (30 μg/10 μg), and ceftadizime (30 μg), ceftadizime plus clavulanic acid (30 μg/10 μg) (Oxoid, UK) to the surface of the inoculated agar plate at 20 mm apart from center disc. Inoculated plates were incubated aerobically at 37° C for 18–24 hours. E. coli ATCC 25922 served as ESBLs negative control strain and Klebsiella pneumoniae ATCC 700603 was used as ESBLs positive control strain. An inhibition zone ≥5 mm between cefotaxime plus clavulanic acid and cefotaxime, or between ceftadizime and ceftadizime plus clavulanic acid and ceftadizime was suggestive of ESBLs production according to CLSI (2022) guidelines.

2.4. Molecular characterization of virulence genes

An overnight pure culture of E. coli was used for the extraction of genomic DNA. This was carried out by suspending 3 to 5 colonies of the fresh culture in 200 ml of sterile distilled water. The suspension was then heated at 98 °C for 8 mins and centrifuged at 17,900 g for 5 min. The supernatant was retrieved and utilized as templates for polymerase chain reactions (PCR) as previously described by Holmes and Quigley (1981). Furthermore, gene amplification was carried out for 16 virulence genes including adhesions, toxins, iron capture systems, protectins, uropathogenic specific protein, and aerobactin system with primers as shown in the Supplementary Table 2. Amplification of virulence genes was carried out in a 5 primer pools; 1 (iron, sfa, iuC, sat), 2 (Cnf1, iutA, papC, hlyD), 3 (usp, ompT, KpsMTII, papA), 4 (KpsMTIII, ibeA), and 5 (hra, ireA). For purposes of this study, E. coli isolates were further analyzed and grouped phylogenetically.

2.5. Phylogenetic analysis

Escherichia coli isolates were subjected to phylogenetic groups using the quadruplex PCR method as described previously by Clermont et al. (2013) based on the presence of the genes chuA, YjaA, TspE4C2, and arpA. According to the amplification results, the E. coli isolates were categorized into one of the major phylogenetic groups: A, B1, B2, C, D, or F. 138 139.

2.6. Molecular characterization of antibiotic resistance genes

Gene amplification was carried out for phenotypic resistant E. coli isolates using primers as shown in Supplementary Table 2. Every reaction mixture comprised of 4 µl of 4 mM MgCl2, 1 µl of 25 pmol of each primer, 2 µl of 2 mM dNTPs, 4 µl of 5x PCR reaction buffer, and 1 U of Taq polymerase to the rest of total 25 µl, including 2 µl DNA template. Gene amplification was done according to amplification conditions as previously described by Maynard et al. (2004) and Sáenz et al. (2004). Resultant PCR products were electrophoresed on a 1.5% agarose gel containing 146 ethidium bromide in 1 x TAE buffer.

2.7. Statistical analysis

Analysis of data was done descriptively with SPSS version 20.0 (SPSS Inc., Chicago, IL). Differences in the frequency of occurrence of isolates, virulence genes, resistance genes, antibiotic response and other variables were examined with Chi square (X²). P value < 0.05 was taken as statistically significant.

3. Results

3.1. Prevalence of virulence genes among various phylogenetic groups of E. coli isolates from Tamale market and Wa abattoir

A total of 49 E. coli isolates were grouped using multiplex PCR with TSPE4C2, chuA, yjaA, and arpA molecular markers. Four major phylogenetic groups were identified among E. coli strains as follows: 7 in group A (14.3%), 18 in group C (36.7%), 15 in group D (30.6%), and 3 (6.1%) in group F (6.1%) Table 1. Several virulence genes were detected including; iutA (10 strains; 5 from phylogenetic group D, 4 from phylogenetic group C and 1 from phylogenetic group A), KpsMTII (10 strains; 6 D, 3 C, and 1 A), ibeA (12 strains; 7 C, 4 D, and 1 A), and sfa (2 strains; 2 D), and papGIII (9 strains; 1 A and 8B2). No papC, sat and cnf1 genes was detected. Table 1 shows the grouping of meat types as a function of the number of virulence genes they bore. Of all the virulence genes encountered in the overall set of meat types, 8 each was detected in strains from guinea fowl meat and local chicken, 10 in isolates from cattle kidney, 6 in isolates from mutton, and 4 each in isolates from cattle liver, beef and chevon. The strains from phylogenetic groups C (18 isolates) and D (15 isolates) contained high numbers of virulence factors. Several virulence patterns stand out, but, the strains with 2 or more virulence genes were from guinea fowl [KpsMTII-ibeA (1), KpsMTII-iutA (1), sfa-iutA (1), iutA-KpsMTII (1)], local chicken [KpsMTII-ibeA (1), KpsMTII-ibeA (1)], mutton [KpsMTII-ibeA (1), iutA-ibeA (1)], cattle kidney [iutA-ibeA (2), sfa-iutA-KpsMTII (1)] and cattle liver iutA-ibeA (1)] Table 1.

Table 1. Prevalence of virulence factors among various phylogenetic groups of E. coli isolates from Tamale market and Wa abattoir.

		Phylogenetic groups (No. of isolates)
Source	Meat type (No.)	A	C	D	F	Unknown
Tamale market	Chevon (6)	iutA(1), none (1)	ibeA(1)	none (2)		ibeA-KpsMTII(1)
	Guinea fowl (7)	none (1)	iutA-KpsMTII (1)	KpsMTII-ibeA (1), KpsMTII (1), KpsMTII-iutA (1), sfa-iutA(1)		None (1)
	Local chicken (8)	KpsMTII-ibeA (1)	iutA(1), ibeA(1), KpsMTII(1), none (1)	KpsMTII-ibeA (1)	ibeA(1), none (1)
	Mutton (7)	ibeA(1)	KpsMTII-ibeA(1), ibeA (1), none (1)	iutA-ibeA (1)	none(1)	ibeA-KpsMTII(1)
Wa abattoir	Beef (7)	none (1)	ibeA(1), none (2)	iutA(1), ibeA(1), none (1)
	Cattle kidney (8)		iutA-ibeA(1), ibeA(1)	iutA-ibeA (1), iutA (1), sfa-iutA-KpsMTII (1) KpsMTIII(1)		ibeA(2)
	Cattle liver (6)	none (1)	iutA-ibeA(1), ibeA (2), none (1)			None (1)
	Total (%)	7 (14.3)	18 (36.7)	15 (30.6)	3 (6.1)	6(12.2)

3.2. Prevalence of antibiotic resistant patterns of meat sample from diverse sources

Table 2 shows the prevalence of antibiotic resistance of E. coli isolates recovered from the various meat types. E. coli isolates from local chicken meat, mutton, guinea fowl meat, cattle kidney and chevon exhibited varying resistance of 16.7% to 87.5% to tetracycline, however, E. coli isolates from cattle liver showed no resistance to tetracycline. With regards to E. coli isolates from local chicken meat, cattle kidney and chevon, they demonstrated resistance of 14.3% to 50% to sulphamethoxazole/trimethoprim. E. coli isolates from guinea fowl meat, local chicken, mutton, chevon and cattle liver showed resistance of 16.7% to 28.6% to ceftriaxone, however, no resistance was detected among E. coli isolates from beef and cattle kidney as shown in Table 2. Thirty-eight (78%) of the E. coli isolates were resistant to at least one antibiotic and 28 (57%) of the isolates were multidrug-resistant (MDR).

Table 2. Prevalence of antibiotic patterns of meat sample from different sources.

		Antibiotics
Source/n= (49) E. coli		Chloramphenicol	Ciprofloxacin	Gentamicin	Ceftriaxone	Sulphamethoxazole-Trimethoprim	Tetracycline
Beef/n = 7	S (%)	85.7	85.7	100	100	85.7	42.9
	I (%)	0	14.3	0	0	0	14.3
	R (%)	14.3	0	0	0	14.3	42.9
Cattle kidney/n = 8	S (%)	87.5	87.5	62.5	100	50	62.5
	I (%)	0	0	37.5	0	0	0
	R (%)	12.5	12.5	0	0	50	37.5
Cattle liver/n = 6	S (%)	100	100	83.3	83.3	83.3	100
	I (%)	0	0	16.7	0	0	0
	R (%)	0	0	0	16.7	16.7	0
Chevon/n = 6	S (%)	100	83.3	100	83.3	66.7	83.3
	I (%)	0	16.7	0	0	0	0
	R (%)	0	0	0	16.7	33.3	16.7
Mutton/n = 7	S (%)	85.7	85.7	57.1	71.4	71.4	42.9
	I (%)	0	0	14.3	0	14.3	0
	R (%)	14.3	14.3	28.6	28.6	14.3	57.1
Local Chicken Meat/n = 8	S (%)	75	75	100	100	50	12.5
	I (%)	12.5	12.5	0	0	0	0
	R (%)	12.5	12.5	0	0	50	87.5
Guinea Fowl Meat/n = 7	S (%)	85.7	85.7	57.1	71.4	71.4	42.9
	I (%)	0	0	14.3	0	14.3	0
	R (%)	14.3	14.3	28.6	28.6	14.3	57.1

S: sensitive, I: intermediate, R: resistant.

3.3. Prevalence of antibiotic resistance genes

Molecular analysis for the presence of resistance genes among phenotypic resistant isolates revealed that 8 E. coli isolates exhibited tet (A) genes in cattle liver (1), cattle kidney (1), chevon (1), beef (1), mutton (1), local chicken meat (1), and guinea fowl meat (2), however, 2 E. coli isolates harboured tet (B) in guinea fowl meat (1) and mutton (1), while an isolates from local chicken meat harboured tet (A) + tet (C) (Table 3). Chloramphenicol gene (florR) was found in 2 E. coli isolates: local chicken meat (1) and guinea fowl meat (1). E. coli isolates from guinea fowl meat was found to harbour blaTEM (1) and another from local chicken meat contained blaCTX-M (1), but no blaSHV was detected (Table 3). Resistance genes occurred more frequently in local chicken meat and local guinea fowl than other meat types.

Table 3. Distribution of resistance genes in E. coli recovered from meat samples.

Isolate/Source (n=)	blaTEM	blaCTX-M	blaSHV	floR	tetA	tetB	tetA+tetC	sul 1	dhfrV
Beef (n = 7)	0	0	0	0	1	0	0	0	0
Cattle kidney (n = 8)	0	0	0	0	1	0	0	0	0
Cattle liver (n = 6)	0	0	0	0	1	0	0	0	0
Chevon (n = 6)	0	0	0	0	1	0	0	0	0
Local guinea fowl (n = 7)	1	0	0	1	2	1	0	1	1
Local chicken (n = 8)	0	1	0	1	1	0	1	0	0
Mutton (n = 7)	0	0	0	0	1	1	0	1	0
Total (n%)	1 (2.04)	1 (2.04)	0 (0)	2 (4.08)	8 (16.3)	2(4.08)	1 (2.04)	2 (4.08)	1 (2.04)

3.4. Occurrence of AMR pattern, AMR genes and virulence in E. coli isolates in Tamale market and WA abatttoir

Generally, there was no significant difference in the susceptibility pattern of E. coli isolates from Tamale market and Wa abattoir. However, a few isolates from Wa abattoir exhibited 100% sensitive to some clinically relevant antibiotic agents including beef source isolates were 100% susceptible to ampicillin, gentamicin and ceftriaxone and cattle liver source isolates were also 100% susceptible to chloramphenicol, ciprofloxacin and tetracycline (Table 4). Among isolates from Tamale market, chevon exhibited 100% sensitivity to chloramphenicol and gentamicin. With regards to AMR pattern, mutton E. coli from Tamale market expressed the most prevalent AMR pattern: AMP-CIP-CTR-GEN-SXT-TET. Also, isolates from local chicken meat source harboured the most dominant AMR genes: blaCTX-M, floR, dhfrV, tetA, tetB, tetA + tetC and sul1. With respect to presence of virulence gene, majority of isolates from Wa abattoir and Tamale market harboured either iutA, ibeA or KpsMTII or a combination these genes. However, isolates from cattle kidney source in Tamale market harboured most diverse virulence genes: iutA, ibeA, iutA-ibeA, and sfa-iutA-KpsMTII (Table 4).

Table 4. Occurrence of antimicrobial resistance patterns, antimicrobial resistance and virulence factors genes in E. coli isolates in Tamale market and Wa abattoir.

			Antibiotics
Location	Meat type/E coli (n)		AMP	CHL	CIP	GEN	CTR	SXT	TET	AMR patterns	AMR genes	Virulence genes
Tamale market	Chevon/n = 6	S (%)	16.7	100	83.3	100	83.3	66.7	83.3			iutA(1), ibeA(1),
		I (%)	0	0	16.7	0	0	0	0	AMP-CRO-TET	tetA(1)	ibeA-KpsMTII(1)
		R (%)	83.3	0	0	0	16.7	33.3	16.7
	Guinea fowl meat/n = 7	S (%)	0	85.7	85.7	57.1	71.4	71.4	42.9
		I (%)	0	0	0	14.3	0	14.3	0	AMP-SXT-TET	blaTEM(1), tetA(2)	iutA-KpsMTII(1)
		R (%)	100	14.3	14.3	28.6	28.6	14.3	57.1		floR(1), tetB(1)	iutA(1), KpsMTII(1), KpsMTII-iutA(1)
	Mutton/n = 7	S (%)	14.3	85.7	85.7	57.1	71.4	71.4	42.9			ibeA(2), iutA-ibeA(1)
		I (%)	0	0	0	14.3	0	14.3	0	AMP-CIP-CTR-GEN	sul1(1), tetA(1), tetB(1)	KpsMTII-ibeA(1)
		R (%)	85.7	14.3	14.3	28.6	28.6	14.3	57.1	SXT-TET		ibeA-KpsMTII(1)
	Local chicken meat/n = 8	S (%)	62.5	85.7	85.7	57.1	71.4	71.4	42.9		blaCTX-M (1), floR(1), dhfrV(1)	ibeA(1), iutA(1), KpsMTII(1)
		I (%)	0	0	0	14.3	0	14.3	0	AMP-CIP-SXT-TET	tetA(1), tetB(1)	ibeA-KpsMTII(2)
		R (%)	37.5	14.3	14.3	28.6	28.6	14.3	57.1		tetA-tetC(1), sul1(1)
Wa abattoir	Beef/n = 7	S (%)	100	85.7	85.7	100	100	85.7	42.9
		I (%)	0	0	14.3	0	0	0	14.3	AMP-SXT-TET	tetA(1)	ibeA(2), iutA(1),
		R (%)	0	14.3	0	0	0	14.3	42.9
	Cattle kidney/n = 8	S (%)	87.5	87.5	87.5	62.5	100	50	62.5			ibeA(3), iutA-ibeA(1), KpsMTII(1), iutA(1)
		I (%)	0	0	0	37.5	0	0	0	AMP-CIP-SXT-TET	tetA(1)	sfa-iutA-KpsMTII(1)
		R (%)	14.3	12.5	12.5	0	0	50	37.5
	Cattle liver/n = 6	S (%)	66.7	100	100	83.3	83.3	83.3	100
		I (%)	33.3	0	0	16.7	0	0	0	AMP-CTR-SXT-TET	tetA(1)	ibeA(2), iutA-ibeA(1)
		R (%)	0	0	0	0	16.7	16.7	0

AMP: Ampicillin, CHL: Chloramphenicol, CIP: Ciprofloxacin, GEN: Gentamicin, CTR: Ceftriaxone, SXT: Sulphomethoxazole-Trimethoprim, TET: Tetracycline, S-Sensitive, I: intermediate, R: Resistant, AMR: Antimicrobial resistant, AST: Antibiotic susceptibility testing.

4. Discussion

Globally, foodborne diseases attributable to diverse bacterial pathogens are of major public health concern (Amore et al., 2021; Handrova & Kmet, 2019). Recently, The World Health Organization for Animal Health (WOAH) has indicated that an estimated 60% of pathogens that cause human diseases can be attributed to animal origins (World Health Organization (WHO), 2021). Several studies have shown that majority of ExPEC strains from food animals can harboured diverse range of virulence determinants associated with extraintestinal diseases in humans and animals (Ewers et al., 2009; 2021; Michalik et al., 2018; Murray et al., 2022). In this study, the most prevalent virulence determinant was ibeA (71.4%), followed by iutA (24.5%), KpsMTII (20.4%), papGIII (18.4%) and sfa (4.1%). However, no papC, sat, and cnf1 genes were detected. This study showed that isolates from local chicken meat, guinea fowl meat, mutton, cattle liver and cattle kidney exhibited 2 or more major virulence genes involved in pathogenesis of ExPEC strains as shown in previous studies (Borzi et al., 2018; Jakobsen et al., 2011). According to Johnson and coworkers (2007), ExPEC may be defined as E. coli isolates harbouring two or more major virulence determinants as demonstrated by multiplex PCR reactions, including papA genes and/or papC, sfa/foc, kpsMT II and iutA. This study findings are indicative that livestock and poultry may act as reservoirs of human pathogenic E. coli, therefore reiterating its zoonotic potentials (Borzi et al., 2018; Foster-Nyarko et al., 2021; Jakobsen et al., 2011; Michalik et al., 2018). In this study, beef harboured the least number of virulence genes. A study by Sukkua et al. (2017) in Thailand detected no ExPEC strains among beef samples examined during 2016 to 2017.

Another study by Xia et al. (2011) reported that beef samples are not major sources of ExPEC strains. IbeA invasion genes and K2 capsular antigen are S-fimbrial adhesins with capacity to bind extracellular matrix components of siaglycoprotein on the brain. As seen in APEC and NMEC strains responsible for meningitis, and sepsis in human (Solà-Ginés et al., 2015; Sora et al., 2021). papGIII is involved in the inflammation of bladder in children and women, and the presence of aerobactin siderophore receptor genes (iutA) is linked with the sequestering of iron uptake from the host to enhance growth of EPEC strains (Sora et al., 2021). In this study, majority of virulence genes were harboured by phylogenetic groups C [17 (34.7%)] and D [15 (30.8%)]. Similar finding of phylogenetic group D (14.3%), C (4.8%), and F (9.5%) have been reported in Brazil among guinea fowls (Borzi et al., 2018). In contrast to Aslam et al. (2014) study in Canada, most of the virulence genes were carried by phylogenetic group B2 (24), and D (18), respectively. In China, lower prevalence of phylogenetic group C (5.4%) and F (7.2%) have been reported among retail chicken meats (Wang et al., 2021). More recently, some studies have highlighted a high virulence gene content association with phylogroup D (Wilkinson et al., 2022). This may be attributed to the pathogenic role exhibited by phylogroup D as one of the major phylogenetic groups responsible for extraintestinal infections (Manges, 2016). Several Studies have shown that a combination of antibiotic resistance and virulence potentials of E. coli strains in food animals can constitute a critical health risk to consumers (Borzi et al., 2018; Ewers et al., 2021; Foster-Nyarko et al., 2021). More recently, the European union has tightened the rules for strict control of food safety to minimize the dissemination of antibiotic resistant foodborne pathogens (European Food Safety Authority and European Centre for Disease Prevention and Control (EFSA and ECDC (European Food Safety Authority & European Centre for Disease Prevention & Control), 2022). In this study, antibiotic resistance among isolates from local chicken meat, local guinea fowl, mutton and cattle kidney to chloramphenicol, ciprofloxacin, ceftriaxone, sulphamethoxazole-trimethoprim and tetracycline ranged between 12.5% and 85.7%. Almost 78% of the E. coli isolates were resistant to at least one antibiotic and 57% of E. coli isolates were multidrug-resistant (Magiorakos et al., 2012). Similar findings of MDR isolates among different meat types have been reported in studies from Ghana; Brazil, and China (Adzitey, 2020; Borzi et al., 2018; Wang et al., 2021). Variation of resistance to clinically relevant antibiotics may be due to the indiscriminate and inappropriate usage of these antibiotics in the agricultural sector, additionally resistance to antibiotics can equally be acquired from the environment due to the close proximity of food animals to humans (Sacher-Pirklbauer et al., 2021; Wang et al., 2021). In this study, most prevalent resistance genes observed was tetA (8) followed by tetB (2), floR (2), sul1 (2), and dhfrV (1) genes among the different meat types. Similar findings have been observed in studies from Austria and China (Sacher-Pirklbauer et al., 2021; Wang et al., 2021). In the present study, one E. coli isolate from guinea fowl meat harboured blaTEM (2.04%), and another isolate from local chicken meat, harboured blaCTX-M (2.04%). Similar findings of blaTEM 15 and blaCTX-M genes among guinea fowl and chicken meats have been reported in Brazil, Zambia, Gambia, Dakar, Austria, Thailand, and China (Borzi et al., 2018; Foster-Nyarko et al., 2021; Sacher-Pirklbauer et al., 2021; Sukkua et al., 2017; Vounba et al., 2019; Wang et al., 2021). The detection of ESBL genes among E. coli isolates from meat sources is a cause for concern due to the propensity for dissemination of plasmids-mediated ESBL genes to human through consumption of uncooked meats. Furthermore, ESBL genes possess capacity of co-resistance to relevant antibiotics (Sacher-Pirklbauer et al., 2021; Wang et al., 2021).

5. Conclusion

This study revealed that some meat sources in Ghana contaminated with E. coli isolates harboured various virulence and resistance genes and belong to different phylogenetic groupings. This may pose a serious threat to public health. Therefore, continuous surveillance of E. coli strains and related virulence-resistance genes in meat, and meat products is warranted. Furthermore, meats in Ghana should be well cooked prior to consumption.

5.1. Limitation of study

The limited number of isolates used in this study may hinder generalization of result. Furthermore, multi-locus sequencing was not carried due to limited resources which would have revealed the presence of any pandemic sequence type.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Frederick Adzitey

Frederick Adzitey is a Professor of Meat Science and Food Safety. He has 13 years of experience working in laboratories in the United Kingdom, Malaysia and Ghana on meat science and related subjects. His area of interests includes animal production, meat processing and technology; isolation, identification and control of foodborne/milkborne/waterborne pathogens; antibiotic resistance and molecular characterization of foodborne/milkborne/waterborne pathogens. Studying of foodborne, milkborne and waterborne pathogens in one health-context.