Bloodstream infections in patients with malignancies: implications for antibiotic treatment in a Ghanaian tertiary setting

Background

Bloodstream infections (BSI) remain a major cause of mortality in patients with malignancies. We present the first report on the microbiological profile of bacteraemia and fungaemia among cancer patients in Ghana.

Methods

From January 2010 through December 2013, we retrospectively analyzed the spectrum of bloodstream pathogens in cancer patients from Korle-Bu Teaching Hospital, Ghana—focusing on multidrug resistant isolates (MDRs).

Results

Overall BSI were confirmed in 22 % (n = 93/453) of total blood cultures. Our data highlights a co-dominance of Gram-negative (n = 49/93, 52.6 %) and Gram-positive (n = 40/93, 43.0 %) bacteria with the former less likely to infect children than adults [odds ratio (OR), 0.56; 95 % confidence interval (CI) 0.14–0.91; p value = 0.027]. Staphylococcus epidermidis was the most isolated bacteria (30.1 %; n = 28/93). About 61 % (n = 25/41) of Enterobacteriaceae isolates were resistant to cefotaxime; a majority (n = 24/25, 96 %) of which were MDRs and mostly susceptible to amikacin and levofloxacin. Four (80 %) penicillin resistant streptococci were found; 2 of which were MDRs and sensitive to erythromycin and cefuroxime. Methicillin resistant Staphylococcus aureus and vancomycin resistant enterococci were not identified. In multivariate analysis, the Enterobacteriaceae compared to other organisms were significantly associated with multidrug resistance (adjusted OR, 33.6; 95 % CI 6.41–88.73; p value 0.001).

Conclusion

MDRs, especially cefotaxime resistant Enterobacteriaceae, are common among patients with cancer in our institution but vary among different patient populations. The results show that empiric antibiotic treatment for cancer patients cannot be done effectively without regard for selective antimicrobial use based on local epidemiologic data.

Laboratory-based nationwide surveillance of antimicrobial resistance in Ghana

Global efforts are underway to combat antimicrobial resistance (AMR). A key target in this intervention is surveillance for local and national action. Data on AMR in Ghana are limited, and monitoring of AMR is nonexistent. We sought to generate baseline data on AMR, and to assess the readiness of Ghana in laboratory-based surveillance. Biomedical scientists in laboratories across Ghana with capacity to perform bacteriological culture were selected and trained. In-house standard operating protocols were used to perform microbiological investigations on clinical specimens. Additional microbiological tests and data analyses were performed at a centralized laboratory. Surveillance data were stored and analyzed using WHONET program files. A total of 24 laboratories participated in the training, and 1,598 data sets were included in the final analysis. A majority of the bacterial species were isolated from outpatients (963 isolates; 60.3%). Urine (617 isolates; 38.6%) was the most common clinical specimen cultured, compared to blood (100 isolates; 6.3%). Ten of 18 laboratories performed blood culture. Bacteria isolated included Escherichia coli (27.5%), Pseudomonas spp. (14.0%), Staphylococcus aureus (11.5%), Streptococcus spp. (2.3%), and Salmonella enterica serovar Typhi (0.6%). Most of the isolates were multidrug-resistant, and over 80% of them were extended-spectrum beta-lactamases-producing. Minimum inhibitory concentration levels at 50% and at 90% for ciprofloxacin, ceftriaxone, and amikacin on selected multidrug-resistant bacteria species ranged between 2 µg/mL and >256 µg/mL. A range of clinical bacterial isolates were resistant to important commonly used antimicrobials in the country, necessitating an effective surveillance to continuously monitor AMR in Ghana. With local and international support, Ghana can participate in global AMR surveillance.

Epidemiology of pneumococcal carriage in children under five years of age in Accra, Ghana

BACKGROUND

Although the majority of pneumococcal infections occur in the developing world, pneumococcal epidemiology is poorly understood in these settings. The aim of the study was to investigate the epidemiology of pneumococcal carriage among children younger than 5 years at a paediatric healthcare centre in Ghana.

METHOD

Four-hundred and twenty-three children were randomly sampled and nasopharyngeal specimens were collected from them. The specimens were cultured for Streptococcus pneumoniae, and the isolates were subjected to antibiotic susceptibility testing and serotyping by latex agglutination. Epidemiological data on demographic and clinical features of the study subjects were collected.

RESULTS

The prevalence of pneumococcal carriage was 48.9% (207/422), with age groups 43-48 months having the highest carriage prevalence. In the multivariate analysis, pneumococcal carriage was significantly associated with runny nose (odds ratio = 1.9, p = 0.003) and day-care attendance (odds ratio = 1.5, p = 0.04). No pneumococcal resistance was observed for ceftriaxone, while the prevalence of resistance to the other antibiotics tested was: cotrimoxazole 100%, ampicillin 88%, tetracycline 78%, penicillin 63% and erythromycin 24%. Fourteen different pneumococcal serogroups/serotypes were identified and serogroup 6 was the most prevalent (30%), followed by serotype 19 (20%).

CONCLUSIONS

We conclude that pneumococcal carriage among the study children is high and the carried strains have a high level of resistance (> 50%) to several antibiotics. Ceftriaxone is a suitable antibiotic for treating pneumococcal infections in Ghana, and the use of this antibiotic coupled with the pneumococcal vaccination is expected to significantly reduce the burden of pneumococcal disease in the country.

Aetiology of Acute Lower Respiratory Infections among Children Under Five Years in Accra, Ghana

The study aimed to investigate the aetiological agents and clinical presentations associated with acute lower respiratory infections (ALRI) among children under five years old at the Korle-Bu Teaching Hospital in Ghana. This was a cross-sectional study carried from February to December 2001. Nasopharyngeal aspirates and venous blood specimens obtained from 108 children with features suggestive of ALRI, were cultured and the isolated bacterial organisms were identified biochemically. Nasopharyngeal aspirates were also tested for Respiratory Syncitial Virus (RSV) antigen using a commercial kit (Becton Dickinson Directigen RSV test kit). A multiplex reverse transcription-PCR (RT-PCR) was also used to detect and characterize RSV using extracted RNA. Socio-demographic and clinical data were also obtained from the study subjects. Bronchopneumonia (55.5%), bronchiolitis (25%), lobar pneumonia (10.2), non-specific ALRI (4.6%), TB, bronchitis and respiratory distress (0.67%) were diagnosed. The prevalence of septicaemia was 10% and bacteria isolated were Staphylococcus aureus, Streptococcus pneumoniae and enteric bacteria, including Salmonella spp., Enterobacter spp and Klebsiella spp, were isolated. Out of the 108 cases, 18% tested positive for RSV, with two cases having RSV as the only aetiological pathogen detected. The subtyping analysis of RSV strains by a multiplex RT-PCR showed that subgroups A and B circulated in the season of analysis.

Salmonella blood stream infections in a tertiary care setting in Ghana

Background

Despite the clinical significance of Salmonella infections, surveillance data worldwide remains limited and is more so exemplified by the lack of reports from Africa especially in eastern, central and western Africa. This study reports on Salmonella serotypes as significant causes of blood stream infections (BSI) and multidrug antibiotic resistance at Korle-Bu Teaching Hospital in Accra, Ghana.

Methods

Antibiogram patterns, seasonal variations in disease incidence and predisposing factors for infection with Salmonella serotypes were analyzed retrospectively over a 4-year period from January 2010 to December 2013. Blood cultures were processed with BACTEC 9240 blood culture system. Speciation was done with BBL Crystal Enteric/Nonfermenter identification system®, and with slide agglutination using specific antisera. Antimicrobial susceptibility testing was carried out by the Kirby-Bauer disc diffusion method according to Clinical and Laboratory Standard Institute guidelines.

Results

We report a 6.5% (n = 181/2768) prevalence of Salmonella bacteraemia at the Korle-Bu Teaching Hospital; with a preponderance of non-typhoidal salmonellae (NTS) over typhoidal salmonella (TS) (n = 115/181, 63.5% versus n = 66/181, 36.5%; P-value <0.002). Children under 5 years bore the brunt of the disease (n = 93/174, 53.4%). Resistance to ciprofloxacin (n = 1/127, 0.7%), amikacin (n = 3/81, 3.7%), and cefotaxime (n = 6/99, 6.1%) remained low, despite high levels of multidrug resistant Salmonella phenotypes (n = 81/181, 44.2%). In multivariate analysis, and among patients with Salmonella BSI, those < 1 year old had reduced risk of non-typhoidal infections [Odds ratio, 0.51; 95% confidence interval (95% CI), 0.16-0.92, P-value 0.021]. Similarly, patients with cefuroxime resistant strans were at increased risk of having multidrug resistant Salmonella BSI (OR, 8.97; 95% CI, 3.62-24.15; P-value, 0.001).

Conclusions

Salmonellae, predominantly NTS, account for a reasonable low proportion of positive blood cultures in our tertiary care setting; but with significant multidrug resistant phenotypes and low ciprofloxacin and cefotaxime resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0697-7) contains supplementary material, which is available to authorized users.

A comparative survey of the prevalence of human parasites found in fresh vegetables sold in supermarkets and open-aired markets in Accra, Ghana

Background

Consuming raw vegetables offers essential nutrients that one may not get when such vegetables are usually cooked. However, eating them raw may pose a great risk for transmissions of pathogens. Such risks may be influenced by the sources of the vegetables and washing techniques used. The aim of the study was to compare the prevalence and diversity of parasitic pathogens associated with vegetables sold at the two types of markets in Ghana and compare effectiveness of various washing techniques.

Methods

We purchased two batches of samples of cabbage, sweet bell pepper, carrot, lettuce, tomato and onion within a two week interval. The vegetables were washed by three methods and the wash solution was concentrated and analyzed for parasites.

Results

The prevalent parasites detected were Strongyloides stercoralis larvae (43%) and Cryptosporidium parvum oocyst (16%). Others present were Hookworm ova, Entamoeba histolytica cysts, Giardia lamblia cysts, Cyclospora cayetanensis oocysts, Entamoeba coli cysts, Trichuris trichiuria ova, Enterobius vermicularis ova, Isospora belli oocysts and Fasciolopsis buski ova. Contamination was highest in lettuce (61%) and cabbage and the least contaminated was tomato (18%). Contamination of vegetables sold at the open-aired markets was about ten-times that of the supermarkets.

Conclusions

In Ghana, the large open-aired markets are the most patronized and serve as a supply point for most corner shops and stalls. The results thus highlight the potential of fresh vegetables serving as a major source of food-borne disease outbreaks and the contribution of open-aired markets to their transmission. Urgent public education on handling of fresh vegetables is recommended.

Profile and health-related quality of life of Ghanaian stroke survivors

BACKGROUND

Stroke is a leading cause of mortality with a major effect on health-related quality of life (HRQoL). There are no previous studies exploring HRQoL among stroke survivors in Ghana, despite the increasing public health significance of the disease in this country. Here we describe the profile of and factors associated with HRQoL among stroke survivors in Ghana.

METHODS

This was a cross-sectional study involving 156 stroke survivors and 156 age- and sex-matched, apparently healthy controls. A robust HRQoL questionnaire involving seven domains was used to collect data from the study participants. Clinical epidemiology data were also collected from stroke survivors on parameters such as stroke severity and risk factors. Statistical analyses were performed on the interrelationships among the study variables.

RESULTS

The mean ages of the stroke survivors and healthy controls were 58.0 (standard deviation, 11.4) and 57.6 (standard deviation, 12.0) years, respectively. Fifty-three percent (86) of the stroke survivors had mild stroke and 35.3% (55) had moderate stroke, whereas 12.2% (19) had severe stroke. Ischemic infarction was the prevalent stroke subtype (78.1%). Hypertension was the most common risk factor (89%) among the stroke survivors, followed by diabetes (29%). HRQoL scores ranged from 57.7% (cognitive domain) to 80.0% (spirit domain) for stroke survivors, whereas HRQoL scores of the control group ranged from 65.6% (cognitive domain) to 85.2% (soul domain). For each HRQoL domain, significantly higher scores were observed for the control group compared with the stroke survivors, at P<0.05. Determinants of HRQoL of stroke survivors in multivariate analysis included age, stroke severity, poststroke duration, stroke recurrence, frequency of laughter, and negative emotions.

CONCLUSION

The most affected HRQoL domains are of the physical, psychoemotional, and cognitive domains. Rehabilitation of stroke patients in this region should include interventions targeted at these domains and modifying the statistical determinants of HRQoL where possible.

Community awareness of stroke in Accra, Ghana

Background

Community awareness of stroke, especially the risk factors and warning signs is important in the control of the disease. In sub-Saharan Africa, little is known about community awareness of stroke though the brunt of stroke is currently borne in this region. The aim of the study was to evaluate stroke awareness in Accra (capital city of Ghana) particularly, the risk factors and warning signs.

Methods

This was a cross-sectional study involving systematic sampling of 63 households in each of the 11 sub metropolitan areas of Accra. A structured questionnaire was used to collect stroke awareness data from respondents randomly sampled in the selected households. Logistic regression analyses were done to identify predictors of the main outcome variables including recognition of stroke risk factors, stroke warning signs and the organ affected by stroke.

Results

Only 40% (n = 277) of the 693 respondents correctly identified the brain as the organ affected in stroke. Similarly, less than half of the respondents could recognize any of the established stroke risk factors as well as any of the established stroke warning signs. Over 70% (n > 485) of the respondents either believed that stroke is a preventable disease, or lifestyle alterations can be made to reduce the risk of stroke, or stroke requires emergency treatment. In multivariate analysis, predictors of stroke awareness were: age <50 years (OR = 0.56, CI = 0.35-0.92, p = 0.021), presence of a stroke risk factor (OR = 2.37, CI = 1.52-3.71, p < 0.001) and Christian Religion (OR = 14.86, CI = 1.37-161.01, p = 0.03).

Conclusion

Though stroke is perceived as a serious and preventable disease in Accra, community awareness of the risk factors and warning signs is sub-optimal. This indicates that community-based education programs to increase public awareness of stroke could contribute to decreasing the risk of stroke and to increasing the speed of hospital presentation after stroke onset.

Sequencing of bacterial genomes: principles and insights into pathogenesis and development of antibiotics

The impact of bacterial diseases on public health has become enormous, and is partly due to the increasing trend of antibiotic resistance displayed by bacterial pathogens. Sequencing of bacterial genomes has significantly improved our understanding about the biology of many bacterial pathogens as well as identification of novel antibiotic targets. Since the advent of genome sequencing two decades ago, about 1,800 bacterial genomes have been fully sequenced and these include important aetiological agents such as Streptococcus pneumoniae, Mycobacterium tuberculosis, Escherichia coli O157:H7, Vibrio cholerae, Clostridium difficile and Staphylococcus aureus. Very recently, there has been an explosion of bacterial genome data and is due to the development of next generation sequencing technologies, which are evolving so rapidly. Indeed, the field of microbial genomics is advancing at a very fast rate and it is difficult for researchers to be abreast with the new developments. This highlights the need for regular updates in microbial genomics through comprehensive reviews. This review paper seeks to provide an update on bacterial genome sequencing generally, and to analyze insights gained from sequencing in two areas, including bacterial pathogenesis and the development of antibiotics.

Microbial carriage of cockroaches at a tertiary care hospital in ghana

Cockroaches are common in the environment of many hospitals in Ghana; however, little is known about their public health risks. To evaluate potential risks, we investigated the external and internal microbial flora of 61 cockroaches from a tertiary hospital in Ghana and evaluated the antibiotic resistance profiles of the common bacterial species. Standard methods were used in all the microbiological investigations and antibiotic susceptibility testing. A rotavirus carriage rate of 19.7% was observed among the cockroaches. Four types of intestinal parasites were carried externally by the cockroaches, and the most prevalent was Hookworm (4.9%). Eight nosocomial bacteria were isolated from the cockroaches, and the most prevalent was Klebsiella pneumoniae, which occurred internally in 29.5% of the cockroaches and 26.2% externally. Multiple drug resistance among common bacteria isolated from the cockroaches ranged from 13.8% (Escherichia coli) to 41.1% (Klebsiella pneumoniae). Cockroaches constitute an important reservoir for pathogenic microorganisms, and may be important vectors of multiple resistant nosocomial pathogens in the studied hospital.

Vaccination against pneumococcus in West Africa: perspectives and prospects

Background

Pneumococcal vaccination has become obligatory due to the enormous burden of pneumococcal diseases. Quite recently, pneumococcal conjugate vaccines have been developed, and have been shown to be superior to the previous polyvalent polysaccharide vaccine of the organism. Pneumococcal conjugate vaccines (PCVs) are being introduced in many West African countries and it is important to understand the expected performance, relevance, and limitations of these vaccines in the subregion.

Aim

The objective of the study presented here was to provide epidemiological insights into PCVs in West Africa based on the prevailing pneumococcal serotypes in the subregion.

Methods

A systematic review was carried out on pneumococcal serotypes causing invasive and noninvasive diseases in West Africa. Studies included in the review were those that reported at least 20 serotyped pneumococcal isolates and which were conducted prior to the introduction of PCVs in the region in 2009. The proportion of pneumococcal disease associated with each serotype as well as the serotype coverage of various PCVs (PCV7, PCV10, and PCV13) were calculated.

Results

The data covered 718 serotyped pneumococcal isolates from six West African countries: Burkina Faso, Ghana, Nigeria, Mali, Senegal, and The Gambia. The 718 isolates covered more than 20 serotypes. Serotype 1 was the most prevalent serotype (32%), followed by serotype 5 (15%), serotype 6 (7%), serotype 2 (6%), serotype 3 (6%), and serotype 12 (5%). The estimated serotype coverage of PCVs among the West African countries was 2%–36% for PCV7, 39%–80% for PCV10, and 65%–87% for PCV13.

Conclusion

A pneumococcal capsular vaccine for use in West Africa must contain serotypes 1 and 5, the most important serotypes responsible for pneumococcal disease in the region. Consequently, while PCV10 and PCV13 are generally suitable for use in West Africa, PCV7 is unsuitable.

Relationship between antibiotic resistance and sickle cell anemia: preliminary evidence from a pediatric carriage study in Ghana

BACKGROUND

Antibiotics are frequently used among people with sickle cell anemia (homozygous SS or HbSS disease), especially for prophylaxis. However, the relationship between antibiotic resistance and people with HbSS disease has not been adequately studied, especially in the developing world. The objectives of the study were (1) to compare antibiotic resistance patterns of nasal Staphylococcus aureus between children with HbSS disease and children without HbSS disease (healthy children) and (2) to evaluate nasopharyngeal carriage of antibiotic-resistant Streptococcus pneumoniae among children with HbSS disease.

METHODS

This was a prospective cross-sectional study, and the subjects were children under 12 years old. Nasal swabs were collected from 50 children with HbSS disease and 50 children without HbSS disease. Nasopharyngeal swabs were collected from another group of 92 children with HbSS disease. The nasal and nasopharyngeal swabs were cultured for S. aureus and S. pneumoniae, respectively. Susceptibility testing was carried out on the S. aureus and S. pneumoniae isolates for various antibiotics, including penicillin, ampicillin, cefuroxime, erythromycin, cloxacillin, and cotrimoxazole.

RESULTS

The carriage rates of S. aureus among pediatric subjects with HbSS disease and those without HbSS disease were 48% and 50%, respectively (P > 0.05). S. pneumoniae carriage among the pediatric subjects with HbSS disease was 10%. Antibiotic resistance patterns of S. aureus carried by children with HbSS disease and children without HbSS disease were similar, and the S. aureus resistance rates were >40% for the various antibiotics, with the exception of erythromycin and cloxacillin. Low levels of S. pneumoniae resistance (0%-11%) were observed for the various antibiotics tested except cotrimoxazole, which showed an extremely high-percentage resistance (100%).

CONCLUSION

Sickling status is not a risk factor for carriage of S. aureus. In this cohort of Ghanaian children with HbSS disease, S. aureus is higher in carriage and more antibiotic-resistant, compared to S. pneumoniae.

Antibacterial effect of Manuka honey on Clostridium difficile

BACKGROUND

Manuka honey originates from the manuka tree (Leptospermum scoparium) and its antimicrobial effect has been attributed to a property referred to as Unique Manuka Factor that is absent in other types of honey. Antibacterial activity of Manuka honey has been documented for several bacterial pathogens, however there is no information on Clostridium difficile, an important nosocomial pathogen. In this study we investigated susceptibility of C. difficile to Manuka honey and whether the activity is bactericidal or bacteriostatic.

METHODS

Three C. difficile strains were subjected to the broth dilution method to determine minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) for Manuka honey. The agar well diffusion method was also used to investigate sensitivity of the C. difficile strains to Manuka honey.

RESULTS

The MIC values of the three C. difficile strains were the same (6.25% v/v). Similarly, MBC values of the three C. difficile strains were the same (6.25% v/v). The activity of Manuka honey against all three C. difficile strains was bactericidal. A dose-response relationship was observed between the concentrations of Manuka honey and zones of inhibition formed by the C. difficile strains, in which increasing concentrations of Manuka honey resulted in increasing size of zone of inhibition formed. Maximum zone of inhibition was observed at 50% (v/v) Manuka honey and the growth inhibition persisted over 7 days.

CONCLUSION

C. difficile is appreciably susceptible to Manuka honey and this may offer an effective way of treating infections caused by the organism.

Molecular typing of the pneumococcus and its application in epidemiology in sub-Saharan Africa

Molecular typing of the pneumococcus has played a crucial role in understanding the epidemiology of the organism. However, most of what is known about molecular epidemiology of the pneumococcus pertains to the developed world. The brunt of pneumococcal infections is borne by sub-Saharan African countries, which makes epidemiological monitoring of the pneumococcus essential in this region of the world. This review paper focuses on molecular typing of the pneumococcus and what is known about epidemiology of the organism in sub-Saharan Africa based on the various typing methods. Several molecular typing methods are available for typing the pneumococcus and the major ones include multilocus sequence typing (MLST), multilocus enzyme electrophoresis (MLEE), serotyping and DNA fingerprinting methods such as pulsed field gel electrophoresis (PFGE) and amplified fragment length polymorphism (AFLP). Currently, MLST is the most suitable method for typing the pneumococcus. The pneumococcal population structure in sub-Saharan Africa appears to be quite different from that of the developed world, and pneumococcal serotype 1 related to the ST 618 clone and clones of the ST 217 clonal complex are responsible for outbreaks in sub-Saharan Africa.

Understanding the pneumococcus: transmission and evolution

Streptococcus pneumoniae is part of the normal bacterial flora of the narsopharynx, but is also associated with several invasive and non-invasive diseases. Recently, there has been a plethora of research information on the pneumococcus, however, there are few comprehensive review papers discussing the research information. This paper provides a review of the pneumococcus in two vital areas related to its biology including transmission and evolution. Transmission of the pneumococcus is a highly efficient process that usually occurs through respiratory droplets from asymptomatic carriers. Following acquisition, the pneumococcus may only establish in the nasopharynx of the new host, or further progress to sites such as the lungs and cause disease. Pneumococcus transmission risk factors, as well as factors involved in its translocation from the nasophyarnx to diseases sites are still not fully understood. Pneumococcal evolution is dominated by recombination. The recombinational events usually involve genetic exchange with streptococci of the mitis group and some pneumococci are thought to exhibit hyper-recombination.

Population biology of Streptococcus pneumoniae in West Africa: multilocus sequence typing of serotypes that exhibit different predisposition to invasive disease and carriage

Background

Little is known about the population biology of Streptococcus pneumoniae in developing countries, although the majority of pneumococcal infections occur in this setting. The aim of the study was to apply MLST to investigate the population biology of S. pneumoniae in West Africa.

Methods

Seventy three invasive and carriage S. pneumoniae isolates from three West African countries including The Gambia, Nigeria and Ghana were investigated. The isolates covered seven serotypes (1, 3, 5, 6A, 11, 14, 23F) and were subjected to multilocus sequence typing and antibiotic susceptibility testing.

Results

Overall, 50 different sequence types (STs) were identified, of which 38% (29) were novel. The most common ST was a novel clone-ST 4012 (6.5%), and some clones including STs 913, 925, 1737, 2160 and 3310 appeared to be specific to the study region. Two STs including ST 63 and ST 4012 were associated with multiple serotypes indicating a history of serotype switching. ST 63 was associated with serotypes 3 and 23F, while ST 4012 was associated with serotypes 6A and 23. eBURST analyses using the stringent 6/7 identical loci definition grouped the 50 STs into 5 clonal complexes and 65 singletons, expressing a high level of genetic diversity among the isolates. Compared to the other serotypes, serotypes 1 and 5 isolates appeared to be more clonal. Internationally recognized antibiotic resistant clones of S. pneumoniae were generally absent in the population investigated and the only multidrug resistant isolate identified (1/66) belong to the Pneumocococcal Epidemiology Network clone ST 63.

Conclusions

The pneumococcal population in West Africa is quite divergent, and serotypes that are common in invasive disease (such as serotypes 1 and 5) are more likely to be clonal than serotypes that are common in carriage.

Comparative phylogenomics of Streptococcus pneumoniae isolated from invasive disease and nasopharyngeal carriage from West Africans

BACKGROUND

We applied comparative phylogenomics (whole genome comparisons of microbes using DNA microarrays combined with Bayesian-based phylogenies) to investigate S. pneumoniae isolates from West Africa, with the aim of providing insights into the pathogenicity and other features related to the biology of the organism. The strains investigated comprised a well defined collection of 58 invasive and carriage isolates that were sequenced typed and included eight different S. pneumoniae serotypes (1, 3, 5, 6A, 11, 14, 19 F and 23 F) of varying invasive disease potential.

RESULTS

The core genome of the isolates was estimated to be 38% and was mainly represented by gene functional categories associated with housekeeping functions. Comparison of the gene content of invasive and carriage isolates identified at least eleven potential genes that may be important in virulence including surface proteins, transport proteins, transcription factors and hypothetical proteins. Thirteen accessory regions (ARs) were also identified and did not show any loci association with the eleven virulence genes. Intraclonal diversity (isolates of the same serotype and MLST but expressing different patterns of ARs) was observed among some clones including ST 1233 (serotype 5), ST 3404 (serotype 5) and ST 3321 (serotype 14). A constructed phylogenetic tree of the isolates showed a high level of heterogeneity consistent with the frequent S. pneumoniae recombination. Despite this, a homogeneous clustering of all the serotype 1 strains was observed.

CONCLUSIONS

Comparative phylogenomics of invasive and carriage S. pneumoniae isolates identified a number of putative virulence determinants that may be important in the progression of S. pneumoniae from the carriage phase to invasive disease. Virulence determinants that contribute to S. pneumoniae pathogenicity are likely to be distributed randomly throughout its genome rather than being clustered in dedicated loci or islands. Compared to other S. pneumoniae serotypes, serotype 1 appears most genetically uniform.

Self-medication practices with antibiotics among tertiary level students in Accra, Ghana: a cross-sectional study

The study was carried out to estimate the prevalence of self-medication with antibiotics among tertiary level students in Accra (Ghana) and evaluate factors associated with the practice. This was a descriptive cross-sectional study and involved face-to-face interviews of 600 respondents selected by convenient sampling. Prevalence of self medication was 70% (95% CI: 66.3-73.7), and the practice was significantly lower among medically inclined students (OR: 0.2, 95% CI: 0.1-0.4, p < 0.001). Among the respondents who practiced self medication, the most common frequency of antibiotic usage was at intervals of one month (30%, 95% CI: 25.6-34.4%), and the most common antibiotic used was amoxacillin (23.9%, 95% CI: 21.0-26.8%). Treatment failure were reported by 35% (95% CI: 30.5-39.6%) of the respondents, and the main reasons cited for self medication were that, it was less expensive compared to medical care in the hospital and secondly, medical care in hospitals were associated with long delays. Forty nine percent (95% CI: 44.2-53.8%) of the respondents had poor knowledge about the health implications of irrational use of antibiotics, and 46% (95% CI: 41.2-50.8%) did not comply with the completion of the full course of antibiotics. Self medication among tertiary students in Accra is an important public health problem and this may reflect the situation among tertiary students in the whole of Ghana.

Epidemiological aspects of non-human antibiotic usage and resistance: implications for the control of antibiotic resistance in Ghana

OBJECTIVES

To provide insights into the epidemiology of antibiotic usage in animal husbandry in Ghana and its effect on resistance.

METHODS

Three hundred and ninety-five randomly sampled commercial livestock keepers who practised intensive or extensive farming were interviewed about their antibiotic usage practices using a structured questionnaire. Escherichia coli isolated from stool specimens of farmers and their animals were tested against eight antibiotics using the Kirby Bauer method.

RESULTS

Ninety-eight percent (387) of the farmers used antibiotics on animals and the main purpose was to prevent infections in animals; 41% applied antibiotics monthly. The overall prevalence of multiple drug resistance among the E. coli isolates was 91.6%; rates in human and animal isolates were 70.6% and 97.7%, respectively. The prevalence of resistance in animal isolates to the various drugs ranged from 60.8% (amikacin) to 95.7% (ampicillin); the prevalence of resistance in human isolates to the drugs ranged from 2% (cefuroxime) to 94.1% (gentamicin). Animal E. coli isolates showed higher resistance than that of human isolates for five of eight drugs tested.

CONCLUSION

It is concluded that antibiotic usage in animal husbandry in Ghana is more driven by the interest of livestock keepers to prevent and treat animal infections than growth enhancement. Both animal and human E. coli showed high levels of antibiotic resistance, although resistance of animal isolates appeared to be higher than that of humans. There is the need for the development of an antibiotic-resistance management programme in Ghana that will focus simultaneously on human and animal use of antibiotics.

Resistance to antimicrobial drugs in Ghana

Background

Antimicrobial drug resistance is a global issue that affects health, economic, and social development. The problem has been attributed to misuse of antimicrobial agents.

Purpose

To identify the agents of bacterial infection in Ghana, determine their antibiogram, and the possibility of setting up a surveillance program.

Patients and methods

A prospective quantitative study set in various hospitals including two teaching hospitals, seven regional hospitals, and two district hospitals in Ghana. A total of 5099 bacterial isolates from various clinical specimens were collected over a period of 1 year, including data related to the patients. Susceptibility of the isolates was determined by the Kirby–Bauer method. In addition, the minimum inhibitory concentration (MIC) of multidrug-resistant isolates of epidemiological significance was also determined using the E-test.

Results

A wide range of bacterial isolates were identified in both teaching and regional hospitals. High percentage of resistance was observed for tetracycline (82%), cotrimoxazole (73%), ampicillin (76%), and chloramphenicol (75%). Multidrug resistance was observed to a combination of ampicillin, tetracycline, chloramphenicol, and cotrimoxazole. On the other hand, a lower percentage of resistance was observed for ceftriaxone (6.3%), ciprofloxacin (11%), and amikacin (9.9%).

Conclusion

Generally, the prevalence of multidrug resistance was widespread among the various isolates. Some multidrug-resistant strains of Staphylococcus aureus, Salmonella typhi, and non-typhoidal Salmonella (NTS) had high MIC to cefuroxime (>256), gentamicin (>256), and ciprofloxacin (>32).

Internalisation of microbes in vegetables: microbial load of Ghanaian vegetables and the relationship with different water sources of irrigation

The occurrence of pathogens in the internal parts of vegetables is usually associated with irrigation water or contaminated soil and could pose risk to consumers as the internalised pathogens are unaffected by external washing. This study was carried out to assess the rate of internalisation of microbes in common Ghanaian vegetables. Standard microbiological methods were employed in microbial enumeration of vegetables collected at the market and farm levels, as well as irrigation water and soil samples. The overall mean counts of vegetables were 4.0 x 10(3) cfu g(-1); 8.1 x 10(2) cfu g(-1); 2.0 x 10(2) cfu g(-1); 3.5 x 10(2) cfu g(-1) for total bacteria, coliform counts, faecal coliform counts and yeast counts, respectively. The rate of internalisation of coliforms in vegetables irrigated with stream/well water was 2.7 times higher than those irrigated with pipe water. The mean coliform counts (4.7 x 10(7) cfu g(-1)) and faecal coliform counts (1.8 x 10(6) cfu g(-1)) of soil samples were similar to those of stream water suggesting both sources exerted similar contamination rates on the vegetables. Generally, there were no significant variations between the rates of internalisation of microbes at the market and farm levels at p < 05, indicating that internalisation of microbes in the vegetables mainly occurred at the farm level. The study has shown that microbial contamination of vegetables in Ghana is not limited to the external surface, but internal vegetable parts could harbour high microbial loads and pose risk to consumers. Safety practices associated with the commodity should therefore not be limited to external washing only. There is the additional need of heating vegetables to eliminate microbes both externally and internally before consumption.

Invasive disease and paediatric carriage of Streptococcus pneumoniae in Ghana

This study was carried out primarily to evaluate the public health burden related to Streptococcus pneumoniae in Ghana and to provide related preliminary molecular epidemiological data on the organism. Invasive and nasopharyngeal specimens were screened for S. pneumoniae, and isolates were subjected to serotyping, multilocus sequence typing (MLST) and antibiotic susceptibility testing. Overall, the prevalence of S. pneumoniae in cerebrospinal fluid (CSF) was 1.7%, in blood was 0.2%, and in nasopharyngeal specimens was 15.3%. The prevalence of multiple drug resistance among the isolates was 48.6%, while the percentage resistance to various drugs was in the range of 11.1-84.0%. Serotyping of the S. pneumoniae isolates showed 7 different serotypes (3, 6B, 9, 10, 14, 16 and 23F). The extent of coverage of serotypes by the 7-valent pneumococcal conjugate vaccine was 57.1%, for the 10-valent vaccine was 57.1%, and for the 13-valent vaccine was 71.4%. MLST of 7 housekeeping genes of the organism showed a high level of genetic diversity among the isolates. S. pneumoniae appears to be an important organism in invasive infections in Ghana, being the most prevalent organism in CSF in this study. The high multiple drug resistance of the organism observed heightens the public health burden, which may be controlled by pneumococcal conjugate vaccines to a large extent.

Application of the WHO five keys of food safety to improve food handling practices of food vendors in a poor resource community in Ghana

AIM

To apply the WHO five keys of food safety in evidence based training programme for food vendors to improve the handling of street food.

METHODS

A total of 127 food vendors in Accra, the capital city of Ghana were sampled for interviews. Data collection from the vendors focused on (i) food handling practices (ii) environmental and personal hygiene (iii) risk factors of oro-faecal transmission. The data obtained from the study was analysed and utilised alongside the WHO Food Safety Training manual in a training workshop for the food vendors. Food handling practices of the vendors were re-assessed after the training workshop to assess the impact of the training.

RESULTS

The main risk factor of oro-faecal transmission was the washing of food utensils with water that been used for hand washing after toilet attendance. Based on environmental and personal hygiene of the vendors, which were assessed by cleanliness, 16.5% and 4.7% respectively were scored as poor. Generally, majority of the food vendors practiced the WHO five keys of food safety, including keeping clean, separating raw and cooked food, cooking thoroughly, keeping food at safe temperature, and using safe water and raw materials. However, only a small proportion seems to practice them constantly. Impact assessment of the food safety training given to the vendors, showed that 60.5% of the vendors had acquired some knowledge from the workshop and were putting it into practice.

CONCLUSION

Generally, food vendors have information on food safety such as hygiene and disease prevention. However, they require an impulse such as a training workshop to put knowledge on food safety into practice.