Bacteremia and antimicrobial drug resistance over time, Ghana

Plasmid-mediated quinolone resistance determinants in clinical bacterial pathogens isolated from the Western Region of Ghana: a cross-sectional study

Introduction

quinolones are critically important antibiotics that are reserved for treating very severe infections caused by multidrug-resistant bacterial pathogens. However, their indiscriminate uses have resulted in an increased number of resistant strains in many parts of the world including Ghana. We determined the quinolone resistance profile of Gram-negative bacterial pathogens and characterized the underlying molecular determinants of resistance.

Methods

Gram-negative pathogens obtained from clinical specimens at three hospital laboratories were tested for resistance to quinolones and other commonly used antibiotics. ESBL production among the Enterobacterial isolates was confirmed using the combined disc diffusion method. We then used PCR to determine seven types of plasmid-mediated quinolone resistance genes present in the isolates resistant to nalidixic acid and ciprofloxacin.

Results

in this study, 29.5% of the isolates were resistant to ciprofloxacin, with the highest of 50% among E. coli resistance to the other quinolones was levofloxacin (24.4%), norfloxacin (24.9%), and nalidixic acid (38.9%). Significant proportions of the quinolone-resistant isolates were ESBL producers (P-values < 0.001). The aac(6´)-Ib-cr, qnrS, oqxA, and qepA genes were present in 43 (89.6%), 27 (56.3%), 23 (47.9%), and one (2.1%) of the isolates, respectively. None of the isolates tested positive to qnrA, qnrB, and oqxB genes. The presence of the aac(6´)-Ib-cr gene positively correlated with resistance to ceftriaxone, cefotaxime, and gentamicin (P-values < 0.05).

Conclusion

high proportions of Gram-negative bacterial isolates were resistant to quinolones and most of these isolates possessed multiple PMQR genes. There is a need to implement measures to limit the spread of these organisms.

Invasive non-typhoidal Salmonella infections in sub-Saharan Africa: a systematic review on antimicrobial resistance and treatment

BACKGROUND

Non-typhoidal Salmonella (NTS) are a frequent cause of invasive infections in sub-Saharan Africa. They are frequently multidrug resistant (co-resistant to ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol), and resistance to third-generation cephalosporin and fluoroquinolone non-susceptibility have been reported. Third-generation cephalosporins and fluoroquinolones are often used to treat invasive NTS infections, but azithromycin might be an alternative. However, data on antibiotic treatment efficacy in invasive NTS infections are lacking. In this study, we aimed to assess the spatiotemporal distribution of antimicrobial resistance in invasive NTS infections in sub-Saharan Africa and to describe the available evidence and recommendations on antimicrobial treatment.

METHODS

We conducted a systematic review of all available literature on antimicrobial resistance and treatment in invasive NTS infections. We performed a random effects meta-analysis to assess the temporal distribution of multidrug resistance, third-generation cephalosporin resistance, and fluoroquinolone non-susceptibility. We mapped these data to assess the spatial distribution. We provided a narrative synthesis of the available evidence and recommendations on antimicrobial treatment.

RESULTS

Since 2001, multidrug resistance was observed in 75% of NTS isolates from all sub-Saharan African regions (95% confidence interval, 70-80% and 65-84%). Third-generation cephalosporin resistance emerged in all sub-Saharan African regions and was present in 5% (95% confidence interval, 1-10%) after 2010. Fluoroquinolone non-susceptibility emerged in all sub-Saharan African regions but did not increase over time. Azithromycin resistance was reported in DR Congo. There were no reports on carbapenem resistance. We did not find high-quality evidence on the efficacy of antimicrobial treatment. There were no supranational guidelines. The "Access group" antibiotics ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol and "Watch group" antibiotics ceftriaxone, cefotaxime, and ciprofloxacin were recommended as the first-choice antibiotics in national guidelines or reviews. These also recommended (a switch to) oral fluoroquinolones or azithromycin.

CONCLUSIONS

In addition to the widespread multidrug resistance in invasive NTS infections in sub-Saharan Africa, resistance to third-generation cephalosporins and fluoroquinolone non-susceptibility was present in all regions. There was a lack of data on the efficacy of antimicrobial treatment in these infections, and supranational evidence-based guidelines were absent.

Antibiotic resistance patterns in human, animal, food and environmental isolates in Ghana: a review

Many articles have been published on resistant microorganisms isolated from humans, animals, foods and the environment in Ghana. However, there are no reviews that summarize the information on the isolates and antibiotics tested so far in the country. This literature review was completed through “PubMed” and “Google Scholar” searches. We included publications from the period 1975-2015 with a laboratory-based methodology to determine antibiotic resistance of strains isolated in Ghana. In total, 60 articles were included in the analysis with 10% of the articles carrying out nationwide research on antibiotic resistance. The regions of Ghana with the highest published articles were Greater Accra (40%), Ashanti (21.7%) and Northern Region (10%). Most of the studies (86.7%) were related to isolates collected from human samples followed by environmental (5%), animal (3%) and food samples (2%). Ten different bacteria genera were observed in the studies. The most common was Escherichia coli, followed by Staphylococcus spp., Mycobacterium spp. and Streptococcus spp. The highest mean resistance rate was encountered in Escherichia coli (62.2%) followed by Klebsiella spp. (60.4%) and Pseudomonas spp. (52.1%). High resistance rates have been found in Ghana, however, the data are skewed and some regions of the country have been neglected. There is a need for higher quality research to establish and monitor resistance patterns in Upper West, Brong-Ahafo, Volta and Eastern Regions of Ghana.

Antimicrobial-Resistant Bacteria in Infected Wounds, Ghana, 20141

Wound infections are an emerging medical problem worldwide, frequently neglected in under-resourced countries. Bacterial culture and antimicrobial drug resistance testing of infected wounds in patients in a rural hospital in Ghana identified no methicillin-resistant Staphylococcus aureus or carbapenem-resistant Enterobacteriaceae but identified high combined resistance of Enterobacteriaceae against third-generation cephalosporins and fluoroquinolones.

Antibiotic use in a tertiary healthcare facility in Ghana: a point prevalence survey

Background

The global rise and spread of antibiotic resistance is limiting the usefulness of antibiotics in the prevention and treatment of infectious diseases. The use of antibiotic stewardship programs guided by local data on prescribing practices is a useful strategy to control and reduce antibiotic resistance. Our objective in this study was to determine the prevalence and indications for use of antibiotics at the Korle-Bu Teaching Hospital Accra, Ghana.

Methods

An antibiotic point prevalence survey was conducted among inpatients of the Korle-Bu Teaching Hospital between February and March 2016. Folders and treatment charts of patients on admission at participating departments were reviewed for antibiotics administered or scheduled to be administered on the day of the survey. Data on indication for use were also collected. Prevalence of antibiotic use was determined by dividing the number of inpatients on antibiotics at the time of survey by the total number of patients on admission.

Results

Of the 677 inpatients surveyed, 348 (51.4%, 95% CI, 47.6–55.2) were on treatment with antibiotics. Prevalence was highest among Paediatric surgery where 20/22 patients (90.9%, 95% CI, 70.8–98.9) were administered antibiotics and lowest among Obstetrics patients with 77/214 (36%, 95% CI, 29.5–42.8). The indications for antibiotic use were 245/611 (40.1%) for community-acquired infections, 205/611 (33.6%) for surgical prophylaxis, 129/611 (21.1%) for healthcare associated infections and 33/611 (5.4%) for medical prophylaxis. The top five antibiotics prescribed in the hospital were metronidazole 107 (17.5%), amoxicillin-clavulinic acid 82 (13.4%), ceftriaxone 17(12.1%), cefuroxime 61 (10.0%), and cloxacillin 52 (8.5%) respectively. Prevalence of meropenem and vancomycin use was 12(2%) and 1 (.2%) respectively. The majority of patients 181 (52%) were being treated with two antibiotics.

Conclusion

This study indicated a high prevalence of antibiotic use among inpatients at the Korle-Bu Teaching Hospital. Metronidazole was the most commonly used antibiotic; mainly for surgical prophylaxis. There is the need to further explore factors contributing to the high prevalence of antibiotic use and develop strategies for appropriate antibiotic use in the hospital.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0299-z) contains supplementary material, which is available to authorized users.

Situational analysis of antibiotic use and resistance in Ghana: policy and regulation

Background

Antibiotics have played an essential role in decreasing morbidity and mortality from infectious diseases. However, indiscriminate use and unrestricted access is contributing to the emergence of bacterial resistance. This paper reports on a situational analysis of antimicrobial use and resistance in Ghana, with focus on policy and regulation.

Methods

Relevant policy documents, reports, regulations and enactments were reviewed. PubMed and Google search engines were used to extract relevant published papers. Websites of stakeholders such as Ministry of Health (MOH) and its agencies were also reviewed. An interview guide was used to elicit responses from selected officials from these sectors.

Results

Laws and guidelines to control the use of antimicrobials in humans were available but not for animals. There was no National Antimicrobial Policy (NAP). A health practice regulatory law mandates Physicians, Physician Assistants, Midwives and trained Nurses to prescribe antimicrobials. However, antibiotics are widely prescribed and dispensed by unauthorised persons, suggesting weak enforcement of the laws. Antibiotics were also supplied to and from unapproved medicine outlets. The Standard Treatment Guidelines (STG), Essential Medicines List (EML) and the National Health Insurance Scheme Medicines List (NHISML) provide restrictions regarding levels of prescribing of antimicrobials. However, existing guidelines on antibiotic use are mostly not adhered to. The use of Automatic Stop Orders to avoid wastage in the hospitals is also not practiced. Data on use of antibiotics for individuals are not readily available in most facilities. Again, there are no standards or guidelines on veterinary use of antibiotics. Surveillance systems for consumption of antibiotics and resistance monitoring were not in place in most health facilities. However, there is an ongoing national action to create awareness on bacteria resistance, strengthening knowledge through research and surveillance and development of NAP in line with global action plan on antimicrobial resistance.

Conclusion

Absence of national antimicrobial policy, weak regulatory environment and non-adherence to practice standards may have contributed to increased and unregulated access to antimicrobials in Ghana, a catalyst for development and spread of antimicrobial resistance.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-4910-7) contains supplementary material, which is available to authorized users.

Multidrug Resistant Enteric Bacterial Pathogens in a Psychiatric Hospital in Ghana: Implications for Control of Nosocomial Infections

Enteric bacteria are commonly implicated in hospital-acquired or nosocomial infections. In Ghana, these infections constitute an important public health problem but little is known about their contribution to antibiotic resistance. The aim of the study was to determine the extent and pattern of antibiotic resistance of enteric bacteria isolated from patients and environmental sources at the Accra Psychiatric Hospital. A total of 265 samples were collected from the study site including 142 stool and 82 urine samples from patients, 7 swab samples of door handle, and 3 samples of drinking water. Enteric bacteria were isolated using standard microbiological methods. Antibiograms of the isolates were determined using the disc diffusion method. Overall, 232 enteric bacteria were isolated. Escherichia coli was the most common (38.3%), followed by Proteus (19.8%), Klebsiella (17.7%), Citrobacter (14.7%), Morganella (8.2%), and Pseudomonas (1.3%). All isolates were resistant to ampicillin but sensitive to cefotaxime. The resistance ranged from 15.5% to 84.5%. Multidrug resistance was most prevalent (100%) among isolates of Proteus and Morganella and least prevalent among isolates of Pseudomonas (33.3%). Multidrug resistance among enteric bacteria at the study hospital is high and hence there is a need for screening before therapy to ensure prudent use of antibiotics.

Serum albumin and osmolality inhibit Bdellovibrio bacteriovorus predation in human serum

We evaluated the bactericidal activity of Bdellovibrio bacteriovorus, strain HD100, within blood sera against bacterial strains commonly associated with bacteremic infections, including E. coli, Klebsiella pneumoniae and Salmonella enterica. Tests show that B. bacteriovorus HD100 is not susceptible to serum complement or its bactericidal activity. After a two hour exposure to human sera, the prey populations decreased 15- to 7,300-fold due to the serum complement activity while, in contrast, the B. bacteriovorus HD100 population showed a loss of only 33%. Dot blot analyses showed that this is not due to the absence of antibodies against this predator. Predation in human serum was inhibited, though, by both the osmolality and serum albumin. The activity of B. bacteriovorus HD100 showed a sharp transition between 200 and 250 mOsm/kg, and was progressively reduced as the osmolality increased. Serum albumin also acted to inhibit predation by binding to and coating the predatory cells. This was confirmed via dot blot analyses and confocal microscopy. The results from both the osmolality and serum albumin tests were incorporated into a numerical model describing bacterial predation of pathogens. In conclusion, both of these factors inhibit predation and, as such, they limit its effectiveness against pathogenic prey located within sera.

Knowledge of antibiotic resistance and antibiotic prescription practices among prescribers in the Brong Ahafo Region of Ghana; a cross-sectional study

Background

Antibiotic resistance (ABR) has become a major public health challenge in most parts of the world including Ghana and is a major threat to gain in bacterial disease control. The role of prescribers in the control of antibiotics is identified as crucial in developing interventions to control ABR. To guide policy recommendations on ABR, a study was carried out among prescribers to identify gaps in their knowledge of ABR and to document their prescription practices.

Method

A cross-sectional survey was conducted among prescribers from both public and private facilities in the Brong Ahafo Region of Ghana using both quantitative and qualitative methods in 2014.

Results

Three hundred and seventy nine prescribers participated in the quantitative study and a subset of 33 participated in in-depth interviews. Majority (50.0%) of the prescribers interviewed were nurses. Most (51.0%) of the prescribers were located in hospitals. Knowledge of ABR was high among all the prescribers. About 80.0% percent of all prescribers agreed that the antibiotics that are currently used could lose its efficacy in future. There is no singular formal source of information on antibiotic resistance. The prescribers held a strong perception that antibiotic resistance is imminent though their knowledge on various resistant bacterial strains was limited. Prescribers attributed ABR burden to factors such as poor prescription practices and limited ABR control measures. The prescription practices of the prescribers vary but were mostly inappropriate among the lower cadre.

Conclusion

The knowledge of ABR is high among prescribers. There is however a gap in the knowledge and perception of optimal antibiotic prescription practices among prescribers. There is the need for a formal source of information on ABR to support prescriber’s antibiotic prescription practices.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2365-2) contains supplementary material, which is available to authorized users.

Prevalence of antimicrobial resistant pathogens from blood cultures: results from a laboratory based nationwide surveillance in Ghana

Background

Blood stream infections (BSI) are critical medical conditions with high morbidity and mortality. There is paucity of information on BSI from surveillance studies in Ghana.

Aim

This study sought to demonstrate how useful BSI data can be gleaned from population-based surveillance, especially from resource-limited settings.

Methods

Data from a nationwide surveillance of antimicrobial drug resistance (AMR) in Ghana were extracted and analyzed. Secondly, we revived archived Staphylococcus aureus isolates from blood cultures that were cefoxitin resistant (CRSA), and screened these for protein A (spa) and mec A genes.

Results

Overall blood culture positivity was 11.2% (714/6351). All together, participating laboratories submitted 100 multidrug resistant blood culture isolates (Gram-negative = 49 and Gram-positive = 51). Prevalence of some Gram-negative isolates was as follows; Escherichia coli (20.4%), Pseudomonas aeruginosa (16.3%), Enterobacter spp. (14.3%), Salmonella serotype Typhi (8.2%) and Non-typhoidal Salmonella [NTS] (8.2%). Gram-positive pathogens included Staphylococcus aureus (66.7%), coagulase negative S. aureus [CoNS] (17.6%) and Streptococcus pneumoniae (11.8%). No methicillin resistance was confirmed in our CRSA isolates. Most blood stream associated infections were from inpatients (75%) and cultured bacteria were resistant to common and cheaper antimicrobials.

Conclusion

E. coli and S. aureus are common pathogens associated with BSI in Ghana and they are resistant to several antimicrobials. Active and continuous AMR surveillance can serve multiple purposes, including data generation for BSI.

A Systematic Review of the Incidence, Risk Factors and Case Fatality Rates of Invasive Nontyphoidal Salmonella (iNTS) Disease in Africa (1966 to 2014)

This study systematically reviews the literature on the occurrence, incidence and case fatality rate (CFR) of invasive nontyphoidal Salmonella (iNTS) disease in Africa from 1966 to 2014. Data on the burden of iNTS disease in Africa are sparse and generally have not been aggregated, making it difficult to describe the epidemiology that is needed to inform the development and implementation of effective prevention and control policies. This study involved a comprehensive search of PubMed and Embase databases. It documents the geographical spread of iNTS disease over time in Africa, and describes its reported incidence, risk factors and CFR. We found that Nontyphoidal Salmonella (NTS) have been reported as a cause of bacteraemia in 33 out of 54 African countries, spanning the five geographical regions of Africa, and especially in sub-Saharan Africa since 1966. Our review indicates that NTS have been responsible for up to 39% of community acquired blood stream infections in sub-Saharan Africa with an average CFR of 19%. Salmonella Typhimurium and Enteritidis are the major serovars implicated and together have been responsible for 91%% of the cases of iNTS disease, (where serotype was determined), reported in Africa. The study confirms that iNTS disease is more prevalent amongst Human Immunodeficiency Virus (HIV)-infected individuals, infants, and young children with malaria, anaemia and malnutrition. In conclusion, iNTS disease is a substantial cause of community-acquired bacteraemia in Africa. Given the high morbidity and mortality of iNTS disease in Africa, it is important to develop effective prevention and control strategies including vaccination.

The Typhoid Fever Surveillance in Africa Program (TSAP): Clinical, Diagnostic, and Epidemiological Methodologies

BACKGROUND

New immunization programs are dependent on data from surveillance networks and disease burden estimates to prioritize target areas and risk groups. Data regarding invasive Salmonella disease in sub-Saharan Africa are currently limited, thus hindering the implementation of preventive measures. The Typhoid Fever Surveillance in Africa Program (TSAP) was established by the International Vaccine Institute to obtain comparable incidence data on typhoid fever and invasive nontyphoidal Salmonella (iNTS) disease in sub-Saharan Africa through standardized surveillance in multiple countries.

METHODS

Standardized procedures were developed and deployed across sites for study site selection, patient enrolment, laboratory procedures, quality control and quality assurance, assessment of healthcare utilization and incidence calculations.

RESULTS

Passive surveillance for bloodstream infections among febrile patients was initiated at thirteen sentinel sites in ten countries (Burkina Faso, Ethiopia, Ghana, Guinea-Bissau, Kenya, Madagascar, Senegal, South Africa, Sudan, and Tanzania). Each TSAP site conducted case detection using these standardized methods to isolate and identify aerobic bacteria from the bloodstream of febrile patients. Healthcare utilization surveys were conducted to adjust population denominators in incidence calculations for differing healthcare utilization patterns and improve comparability of incidence rates across sites.

CONCLUSIONS

By providing standardized data on the incidence of typhoid fever and iNTS disease in sub-Saharan Africa, TSAP will provide vital input for targeted typhoid fever prevention programs.

Antimicrobial resistance pattern: a report of microbiological cultures at a tertiary hospital in Tanzania

Background

Antimicrobial resistance has been declared by the World Health Organization as a threat to the public health. The aim of this study was to analyze antimicrobial resistance patterns of the common pathogens occurring at the Bugando Medical Centre (BMC), Mwanza, Tanzania to provide data for antimicrobial stewardship programmes.

Methods

A total of 3330 microbiological culture results scripts representing non-repetitive specimens reported between June 2013 and May 2015 were retrieved and analyzed for pathogens and their susceptibility patterns using STATA-11 software.

Results

Out of 3330 specimens, 439 (13.2%) had positive culture. Staphylococcus aureus (n = 100; 22.8%), Klebsiella pneumoniae (n = 65; 14.8%) and Escherichia coli (n = 41; 9.3%) were the most frequently isolated bacteria. Of 78 Staphylococcus aureus tested, 27 (34.6%) were found to be methicillin resistant Staphylococcus aureus (MRSA). Rates of resistance of Klebsiella pneumoniae and Escherichia coli isolates to third generation cephalosporins were 38.5% (25/65) and 29.3% (12/41) respectively. Staphylococcus aureus and Klesbiella pneumoniae were commonly isolated from bloodstream infections while Escherichia coli and Pseudomonas aeruginosa were the predominant isolates from urinary tract and wounds infections respectively. Of 23 Salmonella species isolated, 22 (95%) were recovered from the blood. Nine of the 23 Salmonella species isolates (39%) were found to be resistant to third generation cephalosporins. The resistance rate of gram-negative bacteria to third generation cephalosporins increased from 26.5% in 2014 to 57.9% in 2015 (p = 0.004) while the rate of MRSA decreased from 41.2% in 2013 to 9.5% in 2015 (p = 0.016). Multidrug-resistant gram-negative isolates were commonly isolated from Intensive Care Units and it was noted that, the majority of invasive infections were due to gram-negative bacteria.

Conclusion

There is an increase in proportion of gram-negative isolates resistant to third generation cephalosporins. The diversity of potential pathogens resistant to commonly prescribed antibiotics underscores the importance of sustained and standardized antimicrobial resistance surveillance and antibiotic stewardship programmes in developing countries.

Prevalence of Salmonella Excretion in Stool: A Community Survey in 2 Sites, Guinea-Bissau and Senegal

BACKGROUND

Chronic and convalescent carriers play an important role in the transmission and endemicity of many communicable diseases. A high incidence of Salmonella enterica serovar Typhi and invasive nontyphoidal Salmonella (NTS) infection has been reported in parts of sub-Saharan Africa, yet the prevalence of Salmonella excretion in the general population is unknown.

METHODS

Stool specimens were collected from a random sample of households in 2 populations in West Africa: Bissau, Guinea-Bissau, and Dakar, Senegal. Stool was cultured to detect presence of Salmonella, and antimicrobial susceptibility testing was performed on the isolated organisms.

RESULTS

Stool was cultured from 1077 and 1359 individuals from Guinea-Bissau and Senegal, respectively. Salmonella Typhi was not isolated from stool samples at either site. Prevalence of NTS in stool samples was 24.1 (95% confidence interval [CI], 16.5-35.1; n = 26/1077) per 1000 population in Guinea-Bissau and 10.3 (95% CI, 6.1-17.2; n = 14/1359) per 1000 population in Senegal.

CONCLUSIONS

Evidence of NTS excretion in stool in both study populations indicates a possible NTS transmission route in these settings.

High prevalence of human papillomaviruses in Ghanaian pregnant women

Data about the prevalence of human papillomaviruses (HPV) in African women with normal and abnormal cervical cytology are still scarce. Current HPV vaccines contain HPV types, which mainly represent the HPV epidemiology of industrial countries. As further developments of HPV vaccines are going on, it is necessary to regard regional differences in HPV type prevalence to ensure optimal protection by the vaccine. Vaginal swabs of Ghanaian pregnant women, routinely collected before delivery to rule out bacterial infections causing early onset sepsis, were screened for 12 high-risk (HR), 13 probably/possibly (pHR), and 18 low-risk (LR) HPV types. Most pregnant women come for delivery to the hospital. This was considered as appropriate possibility to have an unselected group of women. HPV DNA were detected in 55/165 women (33.3, 95 % CI 26.3-41.1 %). Thirty-four out of fifty-five (61.8, 95 % CI 47.7-74.3 %) of HPV-positive women were infected with HR and/or pHR HPV types. The five most prevalent HR or pHR HPV types were HPV-52 and HPV-67 (7 women each, 4.2, 95 % CI 1.9-8.9 %), HPV-53 (six women, 3.6, 95 % CI 1.5-8.1 %), HPV-45 (five women, 3.0, 95 % CI 1.1-7.3 %), and HPV-18 (four women, 2.4, 95 % CI 0.8-6.5 %), respectively. HPV-16 was found in two women only (1.2, 95 % CI 0.2-4.8 %). Future HPV vaccine research may devote special interest to HPV-67 and HPV-53 provided further studies confirm their high prevalence in the general population of Sub-Saharan African countries. The true carcinogenic potential of HPV-67, which is a member of species alpha9 including HPV-16, and so far categorized as pHR, should be clarified.

Trends in paediatric and adult bloodstream infections at a Ghanaian referral hospital: a retrospective study

Background

Bloodstream infections (BSI) are life-threatening emergencies. Identification of the common pathogens and their susceptibility patterns is necessary for timely empirical intervention.

Methods

We conducted a 4-year retrospective analysis of blood cultures from all patients excluding neonates at the Korle-Bu Teaching hospital, Ghana, from January 2010 through December 2013. Laboratory report data were used to determine BSI, blood culture contamination, pathogen profile, and antimicrobial resistance patterns.

Results

Overall, 3633 (23.16 %) out of 15,683 blood cultures were positive for various organisms. Pathogen-positive cultures accounted for 1451 (9.3 %, 95 % CI 8.5–9.8 %). Infants recorded the highest true blood culture positivity (20.9 %, n = 226/1083), followed by the elderly (13.3 %, n = 80/601), children (8.9 %, n = 708/8000) and adults (7.2 %, n = 437/6000) (p = 0.001 for Marascuilo’s post hoc). Overall occurrence of BSI declined with increasing age-group (p = 0.001) but the type of isolates did not vary with age except for Citrobacter, Escherichia coli, Klebsiella, Salmonella, and Enterococcus species. Gram negative bacteria predominated in our study (59.8 %, n = 867/1451), but the commonest bacterial isolate was Staphylococcus aureus (21.9 %, n = 318/1451)—and this trend run through the various age-groups. From 2010 to 2013, we observed a significant trend of yearly increase in the frequency of BSI caused by cephalosporin-resistant enterobacteria (Chi square for trend, p = 0.001). Meropenem maintained high susceptibility among all Gram-negative organisms ranging from 96 to 100 %. Among Staphylococcus aureus, susceptibility to cloxacillin was 76.6 %.

Conclusion

Our study shows a significantly high blood culture positivity in infants as compared to children, adults and the elderly. There was a preponderance of S. aureus and Gram-negative bacteria across all age-groups. Meropenem was the most active antibiotic for Gram-negative bacteria. Cloxacillin remains a very useful anti-staphylococcal agent.

Electronic supplementary material

The online version of this article (doi:10.1186/s12941-016-0163-z) contains supplementary material, which is available to authorized users.

Clinical and Molecular Epidemiology of Multidrug-Resistant P. aeruginosa Carrying aac(6')-Ib-cr, qnrS1 and blaSPM Genes in Brazil

We described a comprehensive analysis of the molecular epidemiology of multidrug-resistant (MDR) P. aeruginosa. Molecular analysis included typing by Pulsed Field Gel Electrophoresis, identification of genes of interest through PCR-based assays and sequencing of target genes. Case-control study was conducted to better understand the prognostic of patients and the impact of inappropriate therapy in patients with bacteremia, as well as the risk factors of MDR infections. We observed a high rate of MDR isolates (40.7%), and 51.0% of them was independently associated with inappropriate antibiotic therapy. Bacteremia was detected in 66.9% of patients, and prolonged hospital stay was expressive in those resistant to fluoroquinolone. Plasmid-mediated quinolone resistance genes (PMQR), qnrS1 and aac(6')Ib-cr, were detected in two different nosocomial isolates (5.3%), and the aac(6')-Ib7 variant was detected at a high frequency (87.5%) in those negative to PMQR. The presence of mutations in gyrA and parC genes was observed in 100% and 85% of selected isolates, respectively. Isolates harboring PMQR genes or mutations in gyrA and parC were not closely related, except in those containing SPM (São Paulo metallo-β-lactamase) clone. In addition, there is no study published in Brazil to date reporting the presence of Pseudomonas aeruginosa isolates harboring both qnrS1 and aac(6')Ib-cr genes, with alarming frequency of patients with inappropriate therapy.

Multidrug-resistant Salmonella enterica serotype Typhi, Gulf of Guinea Region, Africa

We identified 3 lineages among multidrug-resistant (MDR) Salmonella enterica serotype Typhi isolates in the Gulf of Guinea region in Africa during the 2000s. However, the MDR H58 haplotype, which predominates in southern Asia and Kenya, was not identified. MDR quinolone-susceptible isolates contained a 190-kb incHI1 pST2 plasmid or a 50-kb incN pST3 plasmid.

A retrospective audit of antibiotic prescriptions in primary health-care facilities in Eastern Region, Ghana

Resistance to antibiotics is increasing globally and is a threat to public health. Research has demonstrated a correlation between antibiotic use and resistance development. Developing countries are the most affected by resistance because of high infectious disease burden, limited access to quality assured antibiotics and more optimal drugs and poor antibiotic use practices. The appropriate use of antibiotics to slow the pace of resistance development is crucial. The study retrospectively assessed antibiotic prescription practices in four public and private primary health-care facilities in Eastern Region, Ghana using the WHO/International Network for the Rational Use of Drugs rational drug use indicators. Using a systematic sampling procedure, 400 prescriptions were selected per facility for the period April 2010 to March 2011. Rational drug use indicators were assessed in the descriptive analysis and logistic regression was used to explore for predictors of antibiotic prescription. Average number of medicines prescribed per encounter was 4.01, and 59.9% of prescriptions had antibiotics whilst 24.2% had injections. In total, 79.2% and 88.1% of prescribed medicines were generics and from the national essential medicine list, respectively. In the multivariate analysis, health facility type (odds ratio [OR] = 2.05; 95% confidence interval [CI]: 1.42, 2.95), patient age (OR = 0.97; 95% CI: 0.97, 0.98), number of medicines on a prescription (OR = 1.85; 95% CI: 1.63, 2.10) and 'no malaria drug' on prescription (OR = 5.05; 95% CI: 2.08, 12.25) were associated with an antibiotic prescription. A diagnosis of upper respiratory tract infection was positively associated with antibiotic use. The level of antibiotic use varied depending on the health facility type and was generally high compared with the national average estimated in 2008. Interventions that reduce diagnostic uncertainty in illness management should be considered. The National Health Insurance Scheme, as the main purchaser of health services in Ghana, offers an opportunity that should be exploited to introduce policies in support of rational drug use.

Drinking water from dug wells in rural ghana--salmonella contamination, environmental factors, and genotypes

Salmonellosis is an important but neglected disease in sub-Saharan Africa. Food or fecal-oral associated transmissions are the primary cause of infections, while the role of waterborne transmission is unclear. Samples were collected from different dug wells in a rural area of Ghana and analyzed for contamination with bacteria, and with Salmonella in particular. In addition, temporal dynamics and riks factors for contamination were investigated in 16 wells. For all Salmonella isolates antibiotic susceptibility testing was performed, serovars were determined and strains from the same well with the same serovar were genotyped. The frequency of well water contamination with Gram-negative rod-shaped bacteria was 99.2% (n = 395). Out of 398 samples, 26 (6.5%) tested positive for Salmonella spp. The serovar distribution was diverse including strains not commonly isolated from clinical samples. Resistance to locally applied antibiotics or resistance to fluoroquinolones was not seen in the Salmonella isolates. The risk of Salmonella contamination was lower in wells surrounded by a frame and higher during the rainy season. The study confirms the overall poor microbiological quality of well water in a resource-poor area of Ghana. Well contamination with Salmonella poses a potential threat of infection, thus highlighting the important role of drinking water safety in infectious disease control.

Salmonella Typhi meningitis in a 9-year old boy with urinary schistosomiasis: a case report

Background

Cases of Salmonella Typhi meningitis have been rarely reported in infants. There are few documented cases of persistent salmonella bacteraemia in patients with schistosomiasis. A presented case highlights the importance of broadening the list of pathogens that can cause meningitis among older children in schistosomiasis endemic regions.

Case presentation

The reported case is of a 9-year old sukuma-black African boy referred to Bugando Medical Centre with complaints of fever, abdominal pain, headache and generalized body weakness. On examination; the child was febrile (39°C) with neck stiffness and distended abdomen. Cerebrospinal fluid culture was positive for Salmonella Typhi. In addition on urine sediments microscopy, Schistosoma haematobium eggs were seen. The child improved clinically on ceftriaxone and praziquantel, and was discharged 3 weeks after admission.

Conclusion

Complicated persistent salmonella infection should be considered in schistosomiasis endemic areas. More research should be done to confirm the association between salmonella infections and urinary schistosomiasis.

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.

The association between malaria and non-typhoid Salmonella bacteraemia in children in sub-Saharan Africa: a literature review

Plasmodium falciparum malaria and non-typhoid Salmonella (NTS) bacteraemia are both major causes of morbidity and mortality in children in sub-Saharan Africa. Co-infections are expected to occur because of their overlapping geographical distribution, but accumulating evidence indicates that malaria is a risk factor for NTS bacteraemia. A literature review was undertaken to provide an overview of the evidence available for this association, the epidemiology of malaria-NTS co-infection (including the highest risk groups), the underlying mechanisms, and the clinical consequences of this association, in children in sub-Saharan Africa. The burden of malaria-NTS co-infection is highest in young children (especially those less than three years old). Malaria is one of the risk factors for NTS bacteraemia in children, and the risk is higher with severe malaria, especially severe malarial anaemia. There is insufficient evidence to determine whether asymptomatic parasitaemia is a risk factor for NTS bacteraemia. Many mechanisms have been proposed to explain how malaria causes susceptibility to NTS, ranging from macrophage dysfunction to increased gut permeability, but the most consistent evidence is that malarial haemolysis creates conditions which favour bacterial growth, by increasing iron availability and by impairing neutrophil function. Few discriminatory clinical features have been described for those with malaria and NTS co-infection, except for a higher risk of anaemia compared to those with either infection alone. Children with malaria and NTS bacteraemia co-infection have higher case fatality rates compared to those with malaria alone, and similar to those with bacteraemia alone. Antimicrobial resistance is becoming widespread in invasive NTS serotypes, making empirical treatment problematic, and increasing the need for prevention measures. Observational studies indicate that interventions to reduce malaria transmission might also have a substantial impact on decreasing the incidence of NTS bacteraemia.

Antibacterial resistance in sub-Saharan Africa: an underestimated emergency

Antibacterial resistance-associated infections are known to increase morbidity, mortality, and cost of treatment, and to potentially put others in the community at higher risk of infections. In high-income countries, where the burden of infectious diseases is relatively modest, resistance to first-line antibacterial agents is usually overcome by use of second- and third-line agents. However, in developing countries where the burden of infectious diseases is high, patients with antibacterial-resistant infections may be unable to obtain or afford effective second-line treatments. In sub-Saharan Africa (SSA), the situation is aggravated by poor hygiene, unreliable water supplies, civil conflicts, and increasing numbers of immunocompromised people, such as those with HIV, which facilitate both the evolution of resistant pathogens and their rapid spread in the community. Because of limited capacity for disease detection and surveillance, the burden of illnesses due to treatable bacterial infections, their specific etiologies, and the awareness of antibacterial resistance are less well established in most of SSA, and therefore the ability to mitigate their consequences is significantly limited.

Retrospective analysis of antimicrobial resistance and bacterial spectrum of infection in Gabon, Central Africa

Background

Physicians depend on reliable information on the local epidemiology of infection and antibiotic resistance rates to guide empiric treatment in critically ill patients. As these data are scarce for Central Africa, we performed a retrospective analysis of microbiological findings from a secondary care hospital in Gabon.

Methods

Microbiological reports from 2009 to 2012 were used to assess the non-susceptibility rates of the three most common isolates from six major types of infections (bloodstream, ear-eye-nose-throat, surgical site, skin and soft tissue, urinary tract and wound infection).

Results

A high diversity of pathogens was found, but Staphylococcus aureus was predominant in the majority of infections. Overall, the three most prevalent pathogens in children were S. aureus (33.7%), Streptococcus pyogenes (8.1%) and Escherichia coli (4.5%) and in adults S. aureus (23.5%), E. coli (15.1%) and Klebsiella pneumoniae (7.4%). In total, 5.8% (n = 19) of all S. aureus isolates were methicillin resistant. The proportion of extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae was 15.4% (n = 78), 49.4% of all K. pneumoniae were ESBL-producer (n = 42).

Conclusion

The high diversity of potential pathogens and high resistance rates in Gram-negative bacteria challenge a rational empiric use of antibiotics. Countrywide continuous sentinel surveillance is therefore urgently needed.

Rapid discrimination of Salmonella enterica serovar Typhi from other serovars by MALDI-TOF mass spectrometry

Systemic infections caused by Salmonella enterica are an ongoing public health problem especially in Sub-Saharan Africa. Essentially typhoid fever is associated with high mortality particularly because of the increasing prevalence of multidrug-resistant strains. Thus, a rapid blood-culture based bacterial species diagnosis including an immediate sub-differentiation of the various serovars is mandatory. At present, MALDI-TOF based intact cell mass spectrometry (ICMS) advances to a widely used routine identification tool for bacteria and fungi. In this study, we investigated the appropriateness of ICMS to identify pathogenic bacteria derived from Sub-Saharan Africa and tested the potential of this technology to discriminate S. enterica subsp. enterica serovar Typhi (S. Typhi) from other serovars. Among blood culture isolates obtained from a study population suffering from febrile illness in Ghana, no major misidentifications were observed for the species identification process, but serovars of Salmonella enterica could not be distinguished using the commercially available Biotyper database. However, a detailed analysis of the mass spectra revealed several serovar-specific biomarker ions, allowing the discrimination of S. Typhi from others. In conclusion, ICMS is able to identify isolates from a sub-Saharan context and may facilitate the rapid discrimination of the clinically and epidemiologically important serovar S. Typhi and other non-S. Typhi serovars in future implementations.