Prevalence, toxigenic potential and antimicrobial susceptibility profile of Staphylococcus isolated from ready-to-eat meats

Slaughterhouse facilities in developing nations: sanitation and hygiene practices, microbial contaminants and sustainable management system

Poor personal and environmental hygiene and sanitary conditions of abattoirs in developing countries in sub-Saharan Africa have been implicated in the occurrence and spread of foodborne diseases. This focused review aims to evaluate the sanitation and hygiene practices of slaughterhouses in selected sub-Saharan African countries as well as the microbial (bacterial) contaminants associated with these slaughterhouses. Pathogenic microorganisms of public health importance have been associated with these slaughterhouses due to poor hygiene conditions, non-formal occupational health and safety training, and poor knowledge of workers as well as substandard infrastructures and crude tools in these facilities. Put together, these conditions enable the growth, survival, transmission, and proliferation of foodborne pathogens such as bacteria, parasites, and viruses. To address this issue, there is a need to assess the poor environmental and personal hygiene of butchers and other abattoir workers, the inaccessibility of potable water, waste management practices, and the lack of appropriate infrastructure and technology, which have been identified as some of the enabling factors for bacteria, fungi, and viruses. Sustainable strategies should include instituting regulations that are backed by law.

A Systematic Review and Meta-analysis of Antibiotic Resistance of Foodborne Pathogenic Bacteria in West Africa Between 2010 and 2020

OBJECTIVE

In the past, studies on antimicrobial resistance were carried out on pathogens in the clinical areas. However, since then, this phenomenon has become a general case both in the environment and in the food sector. This systematic review aimed to review the various scientific publications on the resistance of bacteria to antibiotics in foods in West Africa.

METHODS

An extensive literature search was carried out through an electronic database including PubMed, Google Scholar, Research Gate, and African Journals Online (AJOL). Articles published from fifteen countries of the Economic Community of West African States (ECOWAS) between 2010 and 2020 on antibiotic resistance of foodborne pathogens were included in the study. The titles and abstracts of the retrieved articles and then the full texts of the selected articles were reviewed.

RESULTS

Out of the 565 articles found in our initial research, 149 publications (26.55%) were considered suitable for inclusion in this review. Globally, 2018, 2019, and 2020 had more included papers (n = 21 to 25) than the other years. Of the 149 publications analyzed, four types of food commodities were identified as products of high consumption based on the number of publications in the field such as poultry (39/149), read-to-eat food (22/149), meat, and animal products (20/149). Most studies have shown that E. coli has the highest prevalence followed by Salmonella and Staphylococcus. Only 33 (22.14%) of the 149 publications were based on further molecular characterization of the isolates. Publications analyzed showed that the most prevalent detected genes were tet(A), tet(B), tet(C), tet(K) blaTEM, catA1, catA2, cmlA, blaCTXM and qnrA, qnrB, qnrS, parC, and qepA4.

CONCLUSION

From these results, antibiotic use in the food areas must be strongly regulated, especially in developing countries, particularly in Africa. This highlights the need to implement suitable and appropriate control strategies to reduce complications and prevent the dissemination of resistant bacteria isolates in foods. One health antimicrobial resistance surveillance system in the region must be a great concern.

Evaluation of antibacterial, antioxidant, and anti-inflammatory properties of GC/MS characterized methanol leaf extract of Terminalia superba (Combretaceae, Engl. & Diels)

Background

Terminalia superba is a well-known medicinal plant used in folk medicine for the management of various diseases and swelling. Validation of its efficacy in standardized scientific models is lacking. This gap needs to be filled as a way of enhancing modern drug discovery. The aim is to evaluate the antibacterial, antioxidant, and anti-inflammatory properties of T. superba in known and established models. Also, to establish and possibly correlate the established activity with the phytochemicals identified using GC/MS and qualitative methods.

Results

The result showed a dose-dependent percentage inhibition of DPPH, HO•, and Fe3+ reducing activity. The antibacterial activity showed dose-dependent significant (p < 0.05) inhibition against all the organisms used. The anti-inflammatory activity of METS was confirmed in the carrageenan model with significant (p < 0.05) inhibition of paw volume when compared to control while significantly decreasing (p < 0.05) weight of xylene-induced ear. For instance, after 6 h, there was  a reduction of 42%, 33%, and 22% for diclofenac, 200 mg, and 100 mg, respectively, as against 4% in control. The significant (p < 0.05) increase in MDA was attenuated by the treatment with METS dose dependently. Phytochemical assay and GC/MS characterization showed that alkaloids, saponins, phenols, quinone, tannins, coumarins, proteins, flavonoids, and amino acids were dominant with fatty acids accounting for 53%. Others are esters (23%), organic compounds (12%), alkanes (9%), and carboxylic acids (3%).

Conclusions

T. superba possesses antioxidant, antibacterial, and anti-inflammatory properties which are believed to arise from the secondary metabolites observed in the GC–MS characterization.

Graphical Abstract

Prevalence, antibiotic resistance, and enterotoxin production of Staphylococcus aureus isolated from retail raw beef, sheep, and lamb meat in Turkey

The main objective of this study was to isolate and identify Staphylococcus aureus from retail raw red meat samples and evaluate their enterotoxin gene and antibiotic resistance profiles. A total of 452 retail raw meat samples, including beef (n = 200), sheep (n = 125), and lamb (n = 127) randomly purchased from various supermarkets and butchers in Ankara between July 2019 and November 2020, were tested for the prevalence of S. aureus. The S. aureus strain was identified using morphological and molecular (16S rRNA and nuc gene) methods. Moreover, nine Staphylococcal enterotoxin (SE) genes were screened using polymerase chain reaction. Antibiotic resistance of S. aureus was determined using the phenotypic disc diffusion method. The overall prevalence of S. aureus among screened samples was 21.23%. Additionally, 65.62% of S. aureus strains contained SE gene regions. The predominant SEs in the S. aureus strains were sea (50.79%), followed by sed (25.39%) and seb (23.80%). However, sec, see, seg, seh, sei, and sej genes were never detected. A substantial proportion (40-100%) of the isolates were found resistant to kanamycin, telithromycin, penicillin G, streptomycin, erythromycin, cloxacillin, ampicillin, pristinamycin, nalidixic acid, azithromycin, and ciprofloxacin. Multi-drug resistance (MDR) was observed in 96.87% of the S. aureus strains. These results show a low prevalence of S. aureus in raw red meat samples in Turkey. However, a high rate of SEA raises serious health concerns. Due to the high levels of MDR observed in this study, there is a need to strictly control antibiotic use in animals in Turkey.

Profiles of Non-aureus staphylococci in retail pork and slaughterhouse carcasses: prevalence, antimicrobial resistance, and genetic determinant of fusidic acid resistance

As commensal colonizers in livestock, there has been little attention on staphylococci, especially non-aureus staphylococci (NAS), contaminating meat production chain. To assess prevalence of staphylococci in retail pork and slaughterhouse carcass samples in Korea, we collected 578 samples from Korean slaughterhouses (n=311) and retail markets (n=267) for isolation of staphylococci and determined antimicrobial resistance phenotypes in all the isolates. The presence of and prevalence of fusB-family genes (fusB, fusC, fusD, and fusF) and mutations in fusA genes were examined in fusidic acid resistant isolates. A total of 47 staphylococcal isolates of 4 different species (Staphylococcus aureus, n=4; S. hyicus, n=1; S. epidermidis, n=10; Mammaliicoccus sciuri, n=32) were isolated. Fusidic acid resistance were confirmed in 9/10 S. epidermidis and all of the 32 M. sciuri (previously S. sciuri) isolates. Acquired fusidic acid resistance genes were detected in all the resistant strains; fusB and fusC in S. epidermidis and fusB/C in M. sciuri. Multi-locus sequence type analysis revealed that ST63 (n=10, 31%) and ST30 (n=8, 25%) genotypes were most prevalent among fusidic acid resistant M. sciuri isolates. In conclusion, the high prevalence of fusB-family genes in S. epidermidis and M. sciuri strains isolated from pork indicated that NAS might act as a reservoir for fusidic acid resistance gene transmissions in pork production chains.

Epidemiology of gastrointestinal worm infections in pigs reared in Enugu State, Nigeria

Gastrointestinal worm infections (GWI) constrain pig production and zoonotic pig parasites make pork unsafe for human consumption. This study determined the distributions, determinants and dynamics of GWI and also the effect of the infection on production parameters in pigs reared in Enugu State, Nigeria. The GWI were determined by faecal egg counts following standard procedure. Sixty piggeries and 564 pigs were randomly selected for the study. Questionnaire survey was conducted to obtain data on some production parameters and risk practices aiding GWI in the piggeries. An overall prevalence of 88.3% (53/60) and 68.1% (384/564) at farm and individual pig levels respectively were recorded. High egg counts of single and mixed infections involving Strongyle, Ascaris and Trichuris species were found. The infection predominated in young (74.1%, 240/324) and female (72.3%, 272/376) pigs during the rainy/wet season (74.5%, 204/274). Rearing pigs of different ages together, feeding pigs with untreated abattoir/poultry waste, and unhygienic on-farm feed compounding were the major risk practices underpinning acquisition and spread of GWI. Infected piggeries had less litter weight and reduced mean weight at weaning and maturity. Pre-weaning piglet mortality was 15.5%. The seasonality and preponderance of the infection in young and female pigs are useful epidemiological findings which could be exploited for development of an effective control strategy against the parasitic infections. An overhaul of parasitic disease control measures in piggeries in Enugu State is imperative for greater productivity and profitability in swine production, and to boost availability of safe and wholesome pork for human consumption.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12639-021-01377-y.

Virulence Factors in Coagulase-Negative Staphylococci

Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.

Methicillin-Resistant Staphylococcus aureus (MRSA) in Slaughter Houses and Meat Shops in Capital Territory of Pakistan During 2018–2019

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is a major concern in many parts of the world, including Pakistan. The aim of this study was to investigate the prevalence of MRSA in slaughterhouses and meat shops in Rawalpindi-Islamabad, Pakistan, 2018–2019. A total of 300 samples were collected: 40 from each of working area, tools (knives, hooks), butcher hands and beef, 30 from each of chicken and mutton, 20 from each of nasal and rectal swabs. S. aureus was phenotypically identified by performing gram staining and biochemical tests. 150 of the 300 samples were confirmed to be S. aureus by phenotypic identification. MRSA was identified among S. aureus positive isolates by performing disk diffusion test and by detecting S. aureus-specific genes such as 16s rRNA, nuc, mecA, spa, and coa. Out of 150 isolates 96 (63%) showed resistance to antibiotic cefoxitin, known as a potential marker for detecting MRSA. While all 150 isolates have shown complete resistance to the four antibiotics neomycin, methicillin, ciprofloxacin and tetracycline. The nuc and 16s rRNA genes were detected in all 150 S. aureus-positive isolates and 118 (79%) were confirmed to be MRSA through the detection of the mecA gene. MRSA prevalence was highest in chicken (23/30, 77%) followed by beef (25/40, 63%), mutton (15/30, 50%), knives (18/40, 45%), nasal swabs (7/20, 35%), working area (11/40, 28%), rectal swabs (5/20, 25%), hooks (7/40, 18%), and butcher hands (7/40, 18%). 50 MRSA-positive isolates were chosen to identify two virulence factors (spa and coa gene). Of the 50 MRSA isolates subject to coa and spa gene typing, 27 (54%) were positive for the coa gene and 18 (36%) were positive for the spa gene, respectively. To the best of our knowledge, this was the first study on the molecular identification of MRSA in meat samples from Pakistan. High prevalence of MRSA in meat samples demand for implementation of proper hygienic practices and procedures during the slaughtering, transport and marketing of meat and meat products in order to prevent the spread of these bacteria to the human population.

Epidemiology of infections with zoonotic pig parasites in Enugu State, Nigeria

Pig production is an important component of animal agriculture in Nigeria but zoonotic parasites constrain the production and make pork unsafe for human consumption. This epidemiological study was therefore conducted, to ascertain the prevalence and determinants of Taenia solium cysticerci and Ascaris spp infections in pigs in Enugu State. Presence of cysticerci was determined by post-mortem examination of pig carcasses while pig faeces were coprologically examined for presence of Ascaris spp egg, according to standard parasitological protocol. Structured questionnaire was used to elicit information on pig farmers' involvement in practices predisposing to parasitic infections and deworming progammes in 107 piggeries surveyed. Cysticerci were detected in 3.51% (12/342) of pig carcasses inspected. Overall prevalence of Ascaris spp. infections were 38.3% (41/107) and 14.3% (63/441) at farm and individual pig levels respectively. Major determinants of the infection and the percentage of farmers involved were: eating on duty (66.4%), open defecation (35.5%) and semi-extensive husbandry system (62.3%). Others are non-availability of deworming programme (54.4%), rearing pigs of different ages together (41.9%), non-disinfection of feeding or water troughs (41.2%) and early weaning (54.3%). Cognizant of the zoonotic potentials of Ascaris spp and Taenia solium cysticerci, the prevalence found for the parasites are significant from public health and food safety points of view. This underscores the need for cost-effect control measures against the parasites, using a coordinated One Health approach; in order to boost pig production, limit spread of the zoonoses and hence, the public health consequences thereof.

High concentration of coagulase-negative staphylococci carriage among bioaerosols of henhouses in Central China

Background

Coagulase-negative staphylococci (CoNS) are a group of opportunistic pathogens, which are widely spread in the environment. Animal breeding is an important source of pathogen spreading. However, the concentration and characteristics of CoNS in the bioaerosols of henhouses are unclear.

Results

In this study, we showed that CoNS were significantly increased in bioaerosols of henhouses during the first 60 days, and reached 2.0 × 10⁶ CFU/m³, which account for 75.4% of total bacteria. One hundred and two CoNS isolates from bioaerosols and nasal swabs of farmers were further identified, covering seven species. Among these, 41.2% isolates were Staphylococcus sciuri, which was the predominant species, followed by S. equorum, S. saprophyticus, S. haemolyticus, S. xylosus, S. arlettae and S. gallinarum. There were high rates of resistance to oxacillin in CoNS (49.0%), which were defined as Methicillin-Resistant CoNS (MRCoNS), and 36.3% isolates contained resistance gene mecA. Bioaerosol infection models showed that, chickens exposed to aerosolized S. sciuri had significant induction of inflammatory cytokines interleukin (IL)-1β, IL-6, IL-8 and IL-10 at 5 days post-infection (dpi) in lungs and at 7 dpi in spleens.

Conclusions

We reported a high concentration of CoNS in henhouses, and S. sciuri was the preponderant CoNS species. Antibiotic resistance analysis and bioaerosols infection of CoNS further highlighted its hazards on resistance and immunological challenge. These results suggested that, CoNS in bioaerosols could be one serious factor in the henhouses for not only poultry industry but also public health.

Epidemiology of thermotolerant Campylobacter infection in poultry in Nsukka agricultural zone, Nigeria

Backgrond and Aim: Thermotolerant Campylobacter organisms (TCOs) are primary causes of bacterial foodborne gastroenteritis worldwide. Although all warm-blooded animals are susceptible to colonization by TCOs, food-producing animals, especially poultry, are major reservoirs of the infection for transmission to humans. This epidemiological study for thermotolerant Campylobacter infection (TCI) in poultry was, therefore, conducted to determine the prevalence and to identify the risk factors of TCI in 60 randomly selected poultry farms in Nsukka agricultural zone. Materials and Methods: A structured questionnaire was used to elicit information on the farmers' involvement in practices that may aggravate TCI in poultry farms. Isolation of TCOs for the determination of prevalence of the infection was done following standard microbiological protocol. Results: The majority (93.3%) of the farms practiced intensive management system. Farm and individual prevalence of TCI were 78.3% and 19.4%, respectively. The prevalence of 15.7% and 23.6% was recorded for birds reared in urban and rural areas, respectively. Similarly, prevalence rates of 17.2%, 25%, 14.7%, and 24.5% were documented for broiler, layer, male, and female birds, respectively. Major risk factors of TCI found were non-sanitization of drinking water, rearing birds of different ages together, thinning, raising other animals alongside poultry, and overstocking. Conclusion: Overall prevalence of 19.4% is high from public health and food safety points of view. Farmers' participation in the risk factors for TCI is massive. Significant improvement in biosecurity practices in poultry farms in the study area is therefore imperative; to limit TCI in poultry and hence the risk of human infection through the food chain or at the poultry-human interface.

Prevalence and determinants of gastrointestinal parasite infection in intensively managed pigs in Nsukka agricultural zone, Southeast, Nigeria

Gastrointestinal parasite (GIP) infection in pigs constrains swine production and enhances dissemination of zoonotic parasites, especially in the tropics. Therefore, an epidemiological study to determine prevalence and risk factors of GIP infection in intensively managed pigs in Nsukka, was conducted. Faecal samples from 1400 pigs, randomly collected from 40 farms, were examined for GIP eggs following standard protocol. Data on involvement of pig farmers in risk practices that enhance endoparasitic infection in piggeries were obtained using structured questionnaire. Overall prevalence of 80% (32/40) and 28.6% (400/1400) were recorded at farm and individual pig levels, respectively. Prevalence of 25.3% (138/546), 30.7% (262/854), 30.4% (310/1020) and 23.7% (90/380) were obtained for male, female, young (< 1 year) and adult (≥ 1 year) pigs, respectively. Epidemiological factors (sex, age, season, farm location and flock size) were significantly (p < 0.05) associated with worm infestations. Worm eggs identified and their prevalence were: Strongyles 25.7% (360/1400), Trichuris 11.4% (160/1400), Ascaris 0.7% (10/1400) and mixed infections (Strongyles and Trichuris) 9.3% (130/1400). Major risk factors found were feeding of self-compounded on-farm feed, non-disinfection of pen and equipment, rearing pigs of different ages together, infrequent removal of dungs, early weaning at less than 6 weeks and non-availability of routine deworming programme. The overall prevalence at farm and individual pig levels were high; and involvement of farmers in the risk practices was massive. Therefore, cost-effective control of GIP infestations in pig in the study area is imperative; to boost pig production and minimize risk of transmission of zoonotic parasites.