Improving healthcare professionals' interactions with patients to tackle antimicrobial resistance: a systematic review of interventions, barriers, and facilitators.

Introduction: Antimicrobial resistance (AMR) is a major public health threat. With the growing emphasis on patient-centred care/ shared decision making, it is important for healthcare professionals' (HCPs) who prescribe, dispense, administer and/or monitor antimicrobials to be adequately equipped to facilitate appropriate antimicrobial use. We systematically identified existing interventions which aim to improve HCPs interaction with patients and examined barriers and facilitators of appropriate the use of such interventions and appropriate antimicrobial use among both HCPs and patientsantimicrobial use while using these interventions. Methods: We searched MEDLINE, EMBASE, Web of Science, Google Scholar, and internet (via Google search engine). We included primary studies, published in English from 2010 to 2023 [PROSPERO (CRD42023395642)]. The protocol was preregistered with PROSPERO (CRD42023395642). We performed quality assessment using mixed methods appraisal tool. We applied narrative synthesis and used the COM-B (Capability, Opportunity, Motivation -Behaviour) as a theoretical framework for barriers and facilitators at HCP and patient levels. Results: Of 9,172 citations retrieved from database searches, From 4,979 citations remained after removal of duplicates. We included 59 studies spanning over 13 countries. Interventions often involved multiple components beyond HCPs' interaction with patients. From 24 studies reporting barriers and facilitators, we identified issues relating to capability (such as, knowledge/understanding about AMR, diagnostic uncertainties, awareness of interventions and forgetfulness); opportunity (such as, time constraint and intervention accessibility) and motivation (such as, patient's desire for antibiotics and fear of litigation). Conclusion: The findings of this review should be considered by intervention designers/adopters and policy makers to improve utilisation and effectiveness.

Consideration of factors associated with inequalities in interventions that support health-care professionals' interaction with patients to reduce inappropriate antimicrobial use: a systematic review.

BACKGROUND: Tackling the public health challenge of antimicrobial resistance (AMR) requires promotion of appropriate antimicrobial use by health-care professionals. The objective of this review was to identify interventions that facilitate appropriate antimicrobial behaviours when health-care professionals interact with patients and any considerations for factors associated with health inequalities. METHODS: For this systematic review, we searched electronic databases (MEDLINE, EMBASE, Web of Science and Google Scholar) from Jan 31, 2023, to Feb 8, 2023. We included search terms such as antimicrobial use/prescribing, health-care professionals, and AMR programmes. We included any relevant primary study published from year 2010 and in English. We conducted forward and backward citation searching from included studies on March 27, 2023. We extracted information on the interventions following the Template for Intervention Description and Replication (TIDieR) guideline and examined reports on how the interventions might impact on inequalities. We performed quality assessment using the Mixed Methods Appraisal Tool (MMAT). We conducted descriptive synthesis. The protocol is registered with PROSPERO (CRD42023395642). FINDINGS: After screening 4979 records, we included 59 studies. Most studies were randomised trials (n=25) and qualitative/mixed methods studies (n=16). Included studies covered 16 countries, particularly the UK (n=16) and the USA (n=13). Most studies (n=34) fulfilled at least 80% of the relevant quality criteria, but 12 studies fulfilled less than 50%. Many interventions were established strategies (eg, TARGET: Treat Antibiotics Responsibly, Guidance, Education and Tools). Patient interaction elements of the interventions often involved using education materials (eg, digital/paper leaflets, and videos) and point-of-care testing. While many studies (n=49) included participants from disadvantaged groups, only three examined how outcomes differ between groups. In those studies, antimicrobial prescription was not associated with age, sex, and level of learning disability. Some other studies reported issues with language barriers and potential digital exclusion, especially for older people. INTERPRETATION: We might have missed some relevant studies due to publication year and language restrictions. Notwithstanding, this review showed that the potential impact of factors associated with health inequalities are not routinely considered during the implementation and evaluation of interventions to improve health-care professionals' interaction with patients. Future work should routinely consider this to help mitigate potential inequalities. FUNDING: UK Health Security Agency.

Determination of antimicrobial use in commercial poultry farms in Plateau and Oyo States, Nigeria.

BACKGROUND: Indiscriminate use of antimicrobials for the prevention and treatment of bacterial infection in animals is a common practice in Nigeria as in other developing countries. These antimicrobials are purchased over the counter without restrictions and often administered in form of medicated feedstuffs. In Nigeria, like most developing countries, antimicrobial prescription data are not routinely collected or reported at the farm level, instead import data are used in reporting antimicrobial consumption. Farmers can be useful sources of data on the use of antimicrobial agents by class, animal species, production type and age. The objective of the study was to determine the knowledge, attitude and practices of poultry farmers on antimicrobial resistance and to generate data on antimicrobial use (AMU) in poultry farms in Plateau and Oyo states in accordance with the guidelines of the World Organization for Animal Health (WOAH). METHODS: A questionnaire used by the Food and Agriculture Organization (FAO) of the United Nations in Ghana was adopted and modified to collect data on the knowledge, attitude and practices of farmers on AMR and AMU and to collect AMU data from selected poultry farms. A focus group discussion (FGD) was conducted in Plateau state with poultry farmers and representatives from the state veterinary services, using a checklist. The aim of the FGD was to have an idea on antimicrobial use among poultry farmers and to generate additional questions that might be added to the questionnaire. Stratified random sampling technique was used to select 50 farms from Plateau and Oyo states, using the list of registered poultry farms in the two states as sampling frame. RESULTS: Ninety eight percent (98%) of farmers gave antibiotics as prophylactic treatment to day old chicks. There were 47 different products used in the two states within the study period. We observed that five classes of antibiotics (Tetracyclines, Penicillins, Aminoglycosides, Polypeptides and Fluoroquinolone) were used in the two states. A total of 351 kg of active ingredients from seven different classes, namely: tetracyclines, penicillins, aminoglycosides, polypeptide, fluoroquinolones, amphenicol and macrolides were recorded from the two states. Some products contained cocktail of antibiotics, having up to six different classes with very high concentration of active ingredients which are not in the list of registered antimicrobials reported to WOAH. CONCLUSION: The concept used for this survey proved that the approach can be applied for AMU surveillance in the animal health sector. It also provided insight on farmers' knowledge and practices with regards to the use of antimicrobials which is missing in the national import data. The need for "stronger" antibiotics was identified as one of the drivers of antibiotic resistance.

Antibiotic resistance genes, mobile elements, virulence genes, and phages in cultivated ESBL-producing Escherichia coli of poultry origin in Kwara State, North Central Nigeria.

The paucity of information on the genomic diversity of drug-resistant bacteria in most food-producing animals, including poultry in Nigeria, has led to poor hazard characterization and the lack of critical control points to safeguard public health. Hence, this study used whole genome sequencing (WGS) to assess the presence and the diversity of antibiotic resistance genes, mobile genetic elements, virulence genes, and phages in Extended Spectrum Beta Lactamase producing Escherichia coli (ESBL - E. coli) isolates obtained from poultry via the EURL guideline of 2017 in Ilorin, Nigeria. The prevalence of ESBL - E. coli in poultry was 10.5 % (n = 37/354). The phenotypic antibiotic susceptibility testing showed that all the ESBL- E. coli isolates were multi-drug resistant (MDR). The in-silico analysis of the WGS raw-read data from 11 purposively selected isolates showed that the isolates had a wide array of ARGs that conferred resistance to beta-lactam antibiotics, and 8 other classes of antibiotics (fluoroquinolones, foliate pathway antagonists, aminoglycoside, phenicol, tetracycline, epoxide, macrolides, and rifamycin). All the ARGs were in the bacterial chromosome except in two isolates where plasmid-mediated quinolone resistance (PMQR) was detected. Two isolates carried the gyrAp.S83L mutation which confers resistance to certain fluoroquinolones. The mobilome consisted of several Col-plasmids and the predominant IncF plasmids belonged to the IncF64:A-:B27 sequence type. The virulome consisted of genes that function as adhesins, iron acquisition genes, toxins, and protectins. Intact phages were found in 8 of the 11 isolates and the phageome consisted of representatives of four families of viruses: Myoviridae (62.5 %, n = 5/8), Siphoviridae (37.5 %, n = 3/8), Inoviridae (12.5 %, n = 1), and Podoviridae (12.5 %, n = 1/8). ESBL - E. coli isolates harboured 1-5 intact phages and no ARGs were identified on any of the phages. Although five of the isolates belonged to phylogroup A, the isolates were diverse as they belonged to different serotype and sequence types. Our findings demonstrate the high genomic diversity of ESBL - E. coli of poultry origin in Ilorin, Nigeria. These diverse isolates harbor clinically relevant ARGs, mobile elements, virulence genes, and phages that may have detrimental zoonotic potentials on human health.

Co-occurrence of antibiotic and disinfectant resistance genes in extensively drug-resistant Escherichia coli isolated from broilers in Ilorin, North Central Nigeria.

OBJECTIVES: The occurrence of multidrug-resistant (MDR) bacteria in poultry poses the public health threat of zoonotic transmission to humans. Hence, this study assessed the occurrence of drug-resistant Escherichia coli in broilers in the largest live bird market in Kwara State, Nigeria in December 2020. METHODS: Presumptive E. coli isolates were isolated using the European Union Reference Laboratory guideline of 2017 and confirmed via matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Broth microdilution was performed on confirmed E. coli isolates to determine the minimum inhibitory concentration. Five extensively drug-resistant (XDR) isolates were selected for Illumina whole genome sequencing to predict the resistome, phylotype, sequence type, serotype, and diversity of mobile genetic elements in these isolates. RESULTS: Of the 181 broiler caecal samples, 73 E. coli isolates were obtained, of which 67 (82.0%) and 37 (50.6%) were determined as MDR (resistant to at least three classes of antibiotics) and XDR (resistant to at least five classes of antibiotics), respectively. Whole genome sequencing revealed diverse sequence types, phylogroups, and serotypes (ST165/B1 - O80:H19, ST115/A - Unknown: H7, ST901/B1 - O109:H4, ST4087/F - O117:H42, and ST8324/A - O127:H42). The XDR E. coli isolates encoded resistance to fluoroquinolones, fosfomycin, sulfamethoxazole, ampicillin and cephalosporins, trimethoprim, aminoglycosides, chloramphenicol, tetracycline, and macrolides. Mutations in the gyrA gene conferring resistance to fluoroquinolones were also detected. There was a positive correlation between phenotypic resistance patterns and the antibiotic resistance genes that were detected in the sequenced isolates. The XDR isolates also harbored two disinfectant resistance genes (qacE and sitABCD) that conferred resistance to hydrogen peroxide and quaternary ammonium compounds, respectively. The genome of the XDR isolates harbored several mobile genetic elements and virulence-associated genes, which were conserved in all sequenced XDR isolates. CONCLUSIONS: This is the first report of co-carriage of antibiotic resistance genes and disinfectant resistance genes in E. coli isolated from broilers in Ilorin, Nigeria. Our findings suggest that poultry are potential carriers of clonally diverse, pathogenic, MDR/XDR E. coli, which may have detrimental zoonotic potentials on human health.

A national survey of COVID-19 vaccine acceptance in Nigeria.

INTRODUCTION: The COVID-19 vaccine is essential to reduce the global impact of the pandemic. Understanding its acceptance is key to Nigeria's national COVID-19 control strategies. METHODS: Between the 6th and 22nd of January 2021, we conducted a non-probability convenience sampling of 3076 respondents using online and in-person interviews to assess the prevalence and predictors of the COVID-19 vaccine acceptance in Nigeria. FINDINGS: Of the 3076 recruited participants, 74.7% (n = 2300/3076) had tertiary education. The median age group was 30-39 years (35.1%, n = 1097/3076) whereas 31% (n = 952/3076) of all respondents had a monthly income<30,000 Naira (65 USD). The survey results indicated that a wide range of the respondents were in government employment (34.1%, n = 1050/3076). The majority of our study participants (92.2%, n = 2835/3076) believe that COVID-19 is real and not a hoax. Only 27.9% (n = 858/3076) of the study participants have been tested for COVID-19 and 17.8 % (n = 152/858) of the tested respondents were COVID-19 positive by PCR. Half (50.7%; n = 1560/3076) of the study participants were willing to take the vaccine once available. The majority of the respondents (81.1%, n = 2496/3076) were not willing to pay for the vaccine. Only 15.9% (n = 483/3076) of the respondents rated the government's handling of the pandemic above average. The potential acceptance of the COVID-19 vaccine was significantly affected by the age and the monthly income of the respondents. Respondents older than 60 years old (OR: 3.02, 95% CI: 1.69,5.41; p < 0.001) and those that earn between 250,000-500,000 Naira monthly (OR: 1.38; 95% CI: 1.11,1.70; p < 0.001) were more likely to accept the COVID-19 vaccine respectively. In addition, the respondents' perception of the existence of the disease (OR: 1.45; 95% CI: 0.99,2.18; p > 0.05), the need for a COVID-19 vaccine (OR: 16; 95% CI: 11.63,22.10; p < 0.001), the willingness to pay (OR: 1.68; 95% CI: 1.39,2.01; p < 0.001) and the rating of the government handling of the pandemic (OR: 2.25; 95% CI: 1.57,3.23; p < 0.001) were critical to the acceptance of the COVID-19 vaccine. INTERPRETATION: With 50.7% vaccine acceptance, Nigeria's public health policymakers must prioritize and develop strategies that will effectively increase COVID-19 vaccine acceptance across the country with emphasis on trust, transparency and strong leadership.

Knowledge, Attitudes, and Risk Perception of Broiler Grow-Out Farmers on Antimicrobial Use and Resistance in Oyo State, Nigeria.

Assessing knowledge, attitudes, and risk perception of Nigerian broiler grow-out farmers (n = 152) to antimicrobial resistance (AMR) with a five sectional purposive-structured-questionnaire: demographics; knowledge; attitudes; risk-perception; and response to regulation of antimicrobial practices. Data were analyzed using descriptive statistics, chi-square test, and binary logistic regression. Respondents' knowledge score, in total, was lower than average, with all (100%) respondents having the understanding that antibiotics kill/reduce bacteria, most participants (>73%) believing that feeding antibiotics to broiler chickens is a necessity for weight gain, and many (>69%) thinking that no negative side-effects exist with the use of antibiotics. Poor attitude towards antimicrobial usage was prevalent (>63%) with unsatisfactory performance in most instruments: >60% of farmers reported using antimicrobials every week and still use antimicrobials when birds appear sick, and most (>84%) arbitrarily increase the drug dosages when used. However, a satisfactory performance score was reported (68%) in risk perception of AMR with >63% perceiving that inappropriate use of antibiotics is the main factor causing the emergence of resistant bacteria; >65.8% expressed that AMR in broiler chickens is not essential for public health, that AMR cannot develop from broiler bacteria diseases, that increasing the frequency of antimicrobial use cannot increase AMR in future, and that usage cannot lead to antibiotic residue in broiler-meat products leading to AMR development in human. None of the respondents were aware of any regulation for monitoring antimicrobial use. Significant factors associated with knowledge, attitudes, and risk perception of antimicrobial use and resistance among broiler grow-out farmers include marital status, farm category, education, educational specialization, sales target, growth duration/cycle, broiler stocking batch, and feed source. Identified gaps exist in AMR awareness among Nigerian broiler farmers and should be targeted through stakeholders' participation in combatting AMR threats.

Methicillin-Resistant Staphylococcus aureus from Municipal Abattoirs in Nigeria: Showing Highly Similar Clones and Possible Transmission from Slaughter Animals to Humans.

In recent years, methicillin-resistant Staphylococcus aureus (MRSA) has gained interest in veterinary medicine due to its zoonotic potential. Currently, little information is available on the genotypic and virulence characteristics of MRSA isolates detected in Nigerian abattoirs. To better understand the epidemiology of MRSA associated with the abattoir food chain environment in Nigeria, a total of 18 isolates (humans: n = 5, slaughter animals: n = 5, and environment: n = 8), previously spa typed, were recovered and characterized by Staphylococcus cassette chromosome mec (SCCmec) typing, and phenotypic and genotypic antimicrobial susceptibility testing. In addition, 10 of the 18 MRSA strains with a new spa type (t16571) were subjected to multilocus sequence typing. The similarity of strains was analyzed based on the results of the DNA microarray analysis. The 18 MRSA strains harbored two distinct SCCmec types (IVa and V) and belonged to four clonal clusters (CC1, CC7, CC88, and CC152). All MRSA of the new spa type t16571 (n = 10) harbored the SCCmec type IVa. Seven of the MRSA t16571 strains belonged to ST88, while three other strains were assigned to ST3614. The 18 MRSA isolates were categorized into six virulence profiles, and the detection rate for the Panton-Valentine Leukocidin gene was high (33.3%). The antimicrobial susceptibility profiles of the 18 MRSA varied widely between strains, but phenotypic resistance corresponded to relevant resistance genes harbored. The detection of highly similar MRSA strains in slaughter animals, abattoir workers, and the environment underlines the need to use adequate measures at Nigerian abattoirs to prevent further spread and transmission of MRSA to humans or food.

Knowledge and practice of cattle handlers on antibiotic residues in meat and milk in Kwara State, Northcentral Nigeria.

OBJECTIVES: Antibiotics are important for improving animal health and production. However, the deposition of its residues in food of animal origin intended for human consumption at non-permissible levels has generated global health concern and the need to tackle this using the "One Health Approach". This study assessed the knowledge and practice of 286 cattle handlers in Kwara State, Nigeria. METHODS: A web-based cross sectional online survey using a semi-structured questionnaire was conducted from November to December, 2019. Univariate, bivariate and multivariate analyses were performed at 95% confidence interval to determine predictors of good knowledge and practices towards Antibiotic Residues in Meat and Milk among cattle handlers. RESULTS: This study revealed that majority (52.7% n = 165/286) of the cattle handlers were not aware of antibiotic residues. Knowledge and practices regarding antibiotic residues were generally poor among the study population; 36.7% and 35.5% had satisfactory knowledge and practice respectively. The age (p = 0.026), gender (p = 0.006) and business duration (p = 0.001) of participants were significantly associated with their knowledge of antimicrobial residues. The effect of education on knowledge was modified by age. The odds of having poor knowledge on antibiotic residues increased 4 times among participants who were ≤40 years old than those above 40 years (Stratum Specific OR = 3.65; CI = 1.2, 11.1; p = 0.026). Knowledge levels of participants were statistically associated with their practice levels p<0.05 (OR = 2.43; CI = 1.45. 4.06; p = 0.0006). CONCLUSION: This implies that poor knowledge is a risk factor to having poor practice among cattle handlers. Deliberate efforts towards educating cattle farmers on best farm practices in antibiotic use would prevent antibiotic residues in meat and milk. Also, an effective surveillance system for monitoring the use of veterinary drugs in Kwara State, Nigeria is crucial.

Risk Perceptions of Antibiotic Usage and Resistance: A Cross-Sectional Survey of Poultry Farmers in Kwara State, Nigeria.

Overwhelming empirical evidence has highlighted the contribution of indiscriminate antibiotic usage (ABU) in food animals to the overall burden of antibiotic resistance (ABR) in humans, thus making antibiotic use the main selective pressure driving antibiotic resistance. The social and behavioral perspective on antibiotic use and resistance in poultry is limited. Our study therefore aimed at obtaining information on antibiotic usage, awareness of ABR, and the attitude and perceptions towards prudent antibiotic usage and ABR. A cross-sectional survey using a structured questionnaire was conducted in 125 poultry farms in Kwara state in December 2019. Most farmers (69.6%, n = 87/125) were aware of ABR and had satisfactory knowledge about ABR with a mean knowledge score of 3.2 ± 1.5. Age (older farmers; OR: 1.1, 95% CI: 1.0, 1.2) and gender (male respondents, OR: 8.5, 95% CI: 3.0, 23.9; p < 0.01) were more likely to have satisfactory knowledge of ABR. Tertiary education was significantly associated with ABR awareness (OR: 4.7; 95% CI: 0.1, 0.7; p = 0.007) and the ABR knowledge level (OR: 7.8; 95% CI: 3.3, 18.7; p < 0.01). Higher flock size was significantly associated with a satisfactory knowledge of ABR (OR: 9.5; 95% CI: 3.8, 23.6; p < 0.01). Most of the poultry farmers (68%) had positive attitudes towards prudent antibiotic use with a mean score of 2.7 ± 0.9. On the contrary, only 32.8% of poultry farmers had a desirable perception of ABR with a mean perception score of 4.9 ± 1.1. The ABR knowledge level was significantly associated with the perceptions of farmers (p < 0.05) but not their attitudes toward ABU and ABR (p = 0.083). There was evidence of unprescribed use of antibiotics in poultry and a failure to observe antibiotic withdrawal periods. These constitute a risk of exposure to unacceptable levels of drug residues from poultry products and an increased risk of ABR. Improving education and communication on antibiotic stewardship programs are crucial to prevent the looming antibiotic threat.

Knowledge of Antimicrobial Resistance among Veterinary Students and Their Personal Antibiotic Use Practices: A National Cross-Sectional Survey.

The challenge of antimicrobial resistance (AMR) is grave in developing countries. Antimicrobials are misused yet stakeholders' contribution to antimicrobial stewardship is low. Veterinary students are future prescribers and their knowledge could influence progress in combating AMR; hence, there is a need to assess their knowledge, attitude, and awareness of AMR. A multi-institutional questionnaire was administered to undergraduates in Nigerian veterinary schools. It comprised demographics, own personal antibiotic usage, and knowledge, attitude, and awareness of AMR in humans and animals. Descriptive statistics and logistic regression were used for analyses. Of the 426 respondents, 39.2% reported personal antimicrobial use in the previous six months. Over 60% received knowledge scores lower than average and >87% requested more education on clinical use and prescriptions pre-graduation, monitored dispensing of antimicrobials, conducting AMR research, and confirmed link among human, animal, and environmental health. Less than 25% of respondents were aware of antimicrobial stewardship and global efforts/organizations for AMR. Final year students have 9-fold and 14-fold more satisfactory knowledge on antimicrobials in humans and animals compared with other students, respectively (p = 0.001). Final year students also have more knowledge (13×) and awareness of contributory factors (3×) on AMR (p = 0.001) than other students. Unsatisfactory knowledge on AMR issues exists among veterinary students yet willingness to improve was observed. Identified knowledge, attitude, and gaps in AMR awareness should be targeted by veterinary schools in Nigeria.

Staphylococcus aureus in two municipal abattoirs in Nigeria: Risk perception, spread and public health implications.

Staphylococcus aureus is a zoonotic pathogen of significant public health concern. Information on the prevalence and risk factors facilitating bacterial colonization and spread under abattoir settings in Nigeria are scarce. This cross-sectional study was designed to determine prevalence of S. aureus as well as risk factors on knowledge and practices facilitating pathogen carriage among workers and slaughter animals in two municipal abattoirs of Ilorin and Ibadan, Nigeria. Swab samples (n = 1671) from nostrils of cattle, goats, pigs and abattoir workers, and from meat tables and abattoir walls were collected for detection of S. aureus. A questionnaire was administered to 275 workers to elucidate risk factors of pathogen carriage applying a logistic regression model. S. aureus prevalence was 6.5%. In total, MSSA and MRSA were detected at a frequency of 5.4% and 1.1%. Molecular analysis of the isolates revealed 19 different spa types, including a novel spa type (t16751). Gender, marital status, occupation and abattoir location were factors influencing worker's practices in relation to pathogen carriage and spread in the abattoir setting. This present study detected not only low MSSA and MRSA prevalence, in both abattoirs but also low risk perception and hygiene practices employed by abattoir workers. Good practices among workers at Nigerian abattoirs are needed to mitigate S. aureus carriage. Further studies expounding the antibiotic resistance and relationships of MSSA and MRSA strains detected in this study are needed to complement understanding of the spread of S. aureus in the abattoir food chain.

Assessment of the contamination potentials of some foodborne bacteria in biofilms for food products.

OBJECTIVE: To assess biofilms formed by different bacterial strains on glass slides, and changes in biofilm mass and biofilm-associated cell populations after brief contacts between biofilms and either media agar or food products. METHODS: Two Listeria monocytogenes and Escherichia coli (E. coli) strains and a single Staphylococcus aureus (S. aureus) strain were inoculated separately in tryptic soy broth containing glass coupons incubated for 24, 48 or 72 h at 37 °C. The biofilms formed by individual bacterial strains and biofilm-associated cell populations were determined. Biofilms were subsequently allowed to have brief contacts (1-3 times), through gentle touching, with either agar, meat or soft white cheese (2 cm(3)). Changes in biofilm mass on glass slides and cell populations embedded in biofilms were quantified. RESULTS: A nonpathogenic E. coli formed more biofilms than an E. coli O157:H7 strain. Biofilms formed by S. aureus and Listeria monocytogenes were essentially similar. The biofilm mass increased as incubation time increased within 48 h of incubation and was not positively correlated with cellulose production. Biofilm mass at 48 and 72 h of incubation was not significantly different. More frequent contacts with agar or foods did not remove more biofilms or biofilm-associated cells from glass slides. More S. aureus biofilms were removed followed by Listeria and E. coli biofilms. Mean contamination of agar or food models was 0.00 to 7.65 log CFU/cm(2). Greater contaminations in cell populations were observed with S. aureus and Listeria biofilms. CONCLUSIONS: The results provide a clearer assessment of contaminating potential of foods that comes in contact with them.

Biofilm formation by Mycobacterium bovis: influence of surface kind and temperatures of sanitizer treatments on biofilm control.

Mycobacterium bovis causes classic bovine tuberculosis, a zoonosis which is still a concern in Africa. Biofilm forming ability of two Mycobacterium bovis strains was assessed on coupons of cement, ceramic, or stainless steel in three different microbiological media at 37°C with agitation for 2, 3, or 4 weeks to determine the medium that promotes biofilm. Biofilm mass accumulated on coupons was treated with 2 sanitizers (sanitizer A (5.5 mg L(-1) active iodine) and sanitizer B (170.6 g(1) alkyl dimethylbenzyl ammonium chloride, 78 g(-1) didecyldimethyl ammonium chloride, 107.25 g L(-1) glutaraldehyde, 146.25 g L(-1) isopropanol, and 20 g L(-1) pine oil) at 28 and 45°C and in hot water at 85°C for 5 min. Residual biofilms on treated coupons were quantified using crystal violet binding assay. The two strains had a similar ability to form biofilms on the three surfaces. More biofilms were developed in media containing 5% liver extract. Biofilm mass increased as incubation time increased till the 3rd week. More biofilms were formed on cement than on ceramic and stainless steel surfaces. Treatment with hot water at 85°C reduced biofilm mass, however, sanitizing treatments at 45°C removed more biofilms than at 28°C. However, neither treatment completely eliminated the biofilms. The choice of processing surface and temperatures used for sanitizing treatments had an impact on biofilm formation and its removal from solid surfaces.

Biofilms formed by Mycobacterium tuberculosis on cement, ceramic, and stainless steel surfaces and their controls.

This study assessed the biofilms formed by selected strains of Mycobacterium tuberculosis and investigated the efficacy of three different treatments to control the biofilms. Two M. tuberculosis strains were inoculated separately in 150 ml of Middlebrook 7H9-Tween 80 (0.1%) broth with 5% liver extract and 10% oleic albumin dextrose catalase (OADC) supplement, 5% liver extract alone, or 10% OADC alone in sterile jars, each containing a 2-cm2 coupon of cement, ceramic, or stainless steel for biofilm development at 37 °C, with agitation for 2, 3, or 4 weeks. Biofilms on the coupons were exposed to 10 ml of 2% sanitizer A or 0.5% sanitizer B at 28 and 45 °C and to hot water at 85 °C for 5 min. Residual biofilms on treated and untreated coupons were assessed. Both strains of M. tuberculosis formed biofilms on the three surfaces; however, one strain formed more biofilms. More biofilms were formed when media containing 5% liver extract was used. Biofilm mass increased as incubation time increased until the third week. More biofilms were formed on cement than on ceramic and stainless steel coupons. Sanitizing treatments at 45 °C removed more biofilms than those at 28 °C. However, neither treatment completely eliminated the biofilms.

Oxytetracycline and penicillin-G residues in cattle slaughtered in south-western Nigeria: implications for livestock disease management and public health.

After the discovery of indiscriminate antibiotic use in ready-for-slaughter cattle in south-western Nigeria, 90 tissue samples from randomly selected slaughtered cattle were evaluated for oxytetracycline and penicillin-G residues using high performance liquid chromatography and the data analysed by one-way Analysis of variance (ANOVA). The findings revealed residues of oxytetracycline (kidney: 9.47 µ/kg ± 3.24 µ/kg; liver: 12.73 µ/kg ± 4.39 µ/kg; muscle: 16.17 µ/kg ± 5.52 µ/kg) and penicillin-G (kidney: 6.27 µ/kg ± 2.46 µ/kg; liver: 8.5 µ/kg ± 2.80 µ/kg; muscle: 11.67 µ/kg ± 2.94 µ/kg) in all tissues screened. Significantly high levels (oxytetracycline: F = 16.77; penicillin-G: F = 29.38) were, however, found in muscles, followed by liver and then kidney ­ findings confirming recent antibiotic administration to the animals before slaughter. The dietary intakes through the tissues screened were 0.024% (oxytetracycline) and 0.017% (penicillin-G) of the acceptable daily intake (ADI). Although the concentrations in the tissues screened were below the maximum residue limits despite recent administration of these antibiotics before slaughter, the lower concentrations are suggestive of the probable low dosages often administered by those involved in indiscriminate use of antibiotics. This therefore raises serious concerns for the livestock industry as well as human health, given the resultant emergence and spread of resistant strains of bacterial pathogens that could ensue from prolonged use of low dosages of antibiotics. Additionally, the lower concentrations of the daily intakes notwithstanding, the plausible exposure to these antibiotics from other food sources is a cause for concern. Since antimicrobial misuse and its consequent effects are not just a problem limited to Nigeria but also a concern in sub-Saharan Africa, the need for national and international stakeholder intervention is emphasised.

Assessment of tetracycline, lead and cadmium residues in frozen chicken vended in Lagos and Ibadan, Nigeria.

This study determined the levels of tetracycline and heavy metals (lead and cadmium) levels in frozen chicken. One hundred frozen chicken muscle samples were sourced from major markets in Lagos and Ibadan (fifty samples each). The samples were analyzed using high power liquid chromatography (HPLC) for tetracycline residue determination while atomic absorption spectroscopy (AAS) was used to determine the levels of lead and cadmium residues in the samples. Mean concentrations of tetracycline residue levels in the frozen chicken sampled ranged from 1.1589-1.0463ppm which is higher than the maximum residue limit set by international food safety agencies. Pb contents were higher in chicken muscles sampled from markets in Ibadan (0.0227 +/- 0.0069 microg dL(-2)) than Lagos (0.0207 +/- 0.0082 microg dL(-1)), while Cd levels were 0.0013 microg dL(-1) higher than in the Lagos samples (0.0065 +/- 0.0026 microg dL(-1)). These values were within maximum residue limits. There were no significant differences (p < 0.05) in levels of tetracycline, lead and cadmium levels from the two market locations (Lagos and Ibadan) and parts (wings and thigh muscles). However, significant differences occurred in tetracycline and Pb levels in frozen chicken sourced from Cotonou. Though not significant, tetracycline contents in the thigh muscles of the frozen chicken samples was higher than that of the wings muscles and this was attributed to the site of administration of antibiotic injection and failure to observe the pre-slaughter withdrawal period by the farmers. This study is of public health importance as the presence of these residues above the maximum residue limit in frozen chicken predisposes consumers to drug resistance, allergic reactions and poisoning as a result of toxicity.

Heavy metal (lead, Cadmium) and antibiotic (Tetracycline and Chloramphenicol) residues in fresh and frozen fish types (Clarias gariepinus, Oreochromis niloticus) in Ibadan, Oyo State, Nigeria.

This study was carried out to assess the level of heavy metals (lead (Pb) and cadmium (Cd)) and antibiotics (tetracycline and chloramphenicol) residues in frozen and fresh fish types obtained from Eleyele river, Officer's mess, Alfa farm and a major frozen meat outlet in Ibadan, Oyo State Nigeria. The Atomic Absorption Spectrophotometer (AAS) and High Performance Liquid Chromatography (HPLC) were used to analyze the heavy metals and antibiotics residue levels in fresh and frozen fish, respectively. The results showed mean concentrations of antibiotics was higher (p<0.05) in fresh than in frozen fish samples while there were no significant differences in the mean concentrations of heavy metal residue. The differences of mean residue levels in both antibiotics and heavy metals tested in the cranial and caudal parts of the fish samples were not significant (p<0.05). However, there was a significant difference between species (tilapia and catfish) and sources. The highest heavy metals and tetraxycline residues were observed in Alfa's farm (Pb: 0.039+/-0.004 ppm; Cd: 0.020+/-0.006 ppm; tetraxycline: 2.185+/-0.412). Chloramphenicol was highest in Officers mess (0.837+/-0.165 ppm). The heavy metals (Pb and Cd) concentrations determined were below the maximum permissible limits set by both local and international safety agencies. Tetraxcycline exceeded international limits of 0.2 ppm while Chloramphenicol which has a zero tolerance level was also detected from all sources. This study accentuates the need for control of heavy metals and antibiotics in fish sold for human consumption in Ibadan, Nigeria. The need to ban chloramphenicol in treatment of fish and other animals is emphasised.