Salmonellosis in Lagos, Nigeria: Incidence of Plasmodium falciparum-associated Co-infection, Patterns of Antimicrobial Resistance, and Emergence of Reduced Susceptibility to Fluoroquinolones

The present study was undertaken to examine the status of antimicrobial resistance in Salmonella-associated diseases, by verifying possible emergence of reduced susceptibility to fluoroquinolones in Salmonella isolates and determining the incidence of Plasmodium falciparum-associated co-infection with Salmonella serotypes. Antimicrobial resistance in clinical isolates of Salmonellae was examined for a 12-month period. Four hundred and forty-one patients comprising two groups were recruited. Group A comprised 235 patients diagnosed by clinicians of having pyrexia, and group B included stool samples of 206 patients presenting with gastroenteritis. Samples were cultured and isolates identified, and drug susceptibility testing was performed using the standard methods. Of the 235 samples screened in group A, 42 Salmonella isolates and 107 Plasmodium spp. were identified. Of the 42 Salmonella isolates, 19 (45.2%) were Salmonella Typhi, 9 (21.4%) S. Enteritidis, and 7 (16.7%) each of S. Paratyphi and S. Arizonae. Plasmodium spp.-associated co-infection with Salmonellae was observed in 16 patients mostly in complicated typhoidal cases and S. Enteritidis-associated bacteraemia. Fiftty-three of the 206 stool samples from group B patients were confirmed positive for bacterial pathogens, made up of 35 Salmonella and 18 Shigella isolates. Of the Salmonella isolates, 18 (51.4%) were S. Enteritidis, 11 (31.4%) S. Arizonae, 4 (11.4%) S. Paratyphi, and 2 (5.7%) S. Typhi. There was no statistically significant difference (p<0.01) in antimicrobial resistance patterns exhibited among typhoidal Salmonellae isolated in 2000 and 2005. A similar trend in resistance was recorded for non-typhoidal Salmonellae (p<0.05). For the first time in Lagos, Nigeria, Salmonella isolates (10–18%) with reduced susceptibility to both ciprofloxacin and ofloxacin at MIC50 and MIC90 values of 0.015 and 0.03 μg/mL respectively were found. Despite this development, ciprofloxacin and ofloxacin remain the drug of choice for severe cases of salmonellosis, although caution should be exercised by clinicians in their pres-criptions such that fluoroquinolone antibiotic therapy is used only in laboratory-proven cases of typhoid fever and Salmonella-associated bacteraemia to preserve its efficacy

Salmonellosis in Lagos, Nigeria: Incidence of Plasmodium falciparum -associated Co-infection, Patterns of Antimicrobial Resistance, and Emergence of Reduced Susceptibility to Fluoroquinolones

The present study was undertaken to examine the status of antimicrobial resistance in Salmonella-associated diseases, by verifying possible emergence of reduced susceptibility to fluoroquinolones in Salmonella isolates and determining the incidence of Plasmodium falciparum -associated co-infection with Salmonella serotypes. Antimicrobial resistance in clinical isolates of Salmonellae was examined for a 12-month period. Four hundred and forty-one patients comprising two groups were recruited. Group A comprised 235 patients diagnosed by clinicians of having pyrexia, and group B included stool samples of 206 patients presenting with gastroenteritis. Samples were cultured and isolates identified, and drug susceptibility testing was performed using the standard methods. Of the 235 samples screened in group A, 42 Salmonella isolates and 107 Plasmodium spp. were identified. Of the 42 Salmonella isolates, 19 (45.2%) were Salmonella Typhi, 9 (21.4%) S. Enteritidis, and 7 (16.7%) each of S. Paratyphi and S. Arizonae. Plasmodium spp.-associated co-infection with Salmonellae was observed in 16 patients mostly in complicated typhoidal cases and S. Enteritidis-associated bacteraemia. Fiftty-three of the 206 stool samples from group B patients were confirmed positive for bacterial pathogens, made up of 35 Salmonella and 18 Shigella isolates. Of the Salmonella isolates, 18 (51.4%) were S. Enteritidis, 11 (31.4%) S. Arizonae, 4 (11.4%) S. Paratyphi, and 2 (5.7%) S. Typhi. There was no statistically significant difference (p&lt;0.01) in antimicrobial resistance patterns exhibited among typhoidal Salmonellae isolated in 2000 and 2005. A similar trend in resistance was recorded for non-typhoidal Salmonellae (p&lt;0.05). For the first time in Lagos, Nigeria, Salmonella isolates (10-18%) with reduced susceptibility to both ciprofloxacin and ofloxacin at MIC50 and MIC90 values of 0.015 and 0.03 \ub5g/mL respectively were found. Despite this development, ciprofloxacin and ofloxacin remain the drug of choice for severe cases of salmonellosis, although caution should be exercised by clinicians in their prescriptions such that fluoroquinolone antibiotic therapy is used only in laboratory-proven cases of typhoid fever and Salmonella-associated bacteraemia to preserve its efficacy

Human Campylobacteriosis in Developing Countries1

Campylobacteriosis is a collective description for infectious diseases caused by members of the bacterial genus Campylobacter. The only form of campylobacteriosis of major public health importance is Campylobacter enteritis due to C. jejuni and C. coli. Research and control efforts on the disease have been conducted more often in developed countries than developing countries. However, because of the increasing incidence, expanding spectrum of infections, potential of HIV-related deaths due to Campylobacter, and the availability of the complete genome sequence of C. jejuni NCTC 11168, interest in campylobacteriosis research and control in developing countries is growing. We present the distinguishing epidemiologic and clinical features of Campylobacter enteritis in developing countries relative to developed countries. National surveillance programs and international collaborations are needed to address the substantial gaps in the knowledge about the epidemiology of campylobacteriosis in developing countries

Persistence of fluoroquinolone-resistant Salmonella enterica serovar Kentucky from poultry and poultry sources in Nigeria

Introduction: This study investigated the antimicrobial resistance and clonality of Salmonella enterica serotype Kentucky in poultry and poultry sources in Nigeria, and compared the isolates with the clone of S. Kentucky STI98-X1 CIPR using (PFGE) and (MIC). Methodology: Fecal samples from chickens and poultry sources (litter, water, rodent and lizard fecal samples) were collected from  fourteen (14) poultry farms in 2007, 2010 and 2011 and were analyzed for S. Kentucky. Results and conclusions: Six percent of the samples were positive for S. Kentucky – all resistant to nalidixic acid and ciprofloxacin. The isolates are grouped within the PFGE cluster X1 of S. Kentucky STI98 CIPR, indicating the association to the emerging and widely spread CIPR S. Kentucky clone with poultry and poultry sources.</jats:p

CARRIAGE OF MULTIDRUG RESISTANT ENTEROCOCCUS FAECIUM AND ENTEROCOCCUS FAECALIS AMONG APPARENTLY HEALTHY HUMANS

Enterococci are indigenous flora of the gastro-intestinal tracts of animals and humans. The recent years have witnessed increased interest in two major species, E. faecium and E. faecalis, because of their ability to cause serious infections and their intrinsic resistance to antimicrobials. In this study, human faecal samples were processed to determine the frequency of occurrence of E. faecium and E. faecalis and evaluate the susceptibility of the isolates to antibiotics. One hundred faecal samples were collected from apparently healthy individuals and 73 Enterococcus were phenotypically identified using conventional methods. The susceptibility profiles of the isolates to 9 different antibiotics were determined using disk diffusion method and the results were interpreted according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Sixty-five isolates were differentiated into 36 (55.4%) E. faecium and 29 (44.6%) E. faecalis. No dual colonization by the two species was observed and isolation rate was independent of sex. Antimicrobial susceptibility testing revealed high occurrence of several different combinations of resistant patterns. The 65 isolates were resistant to ceftriaxone, cefuroxime and ceftizoxime. Enterococcus faecium exhibited resistance to erythromycin (88.9%), gentamicin (77.8%), amoxicillin-clavulanate (63.9%), ofloxacin (44.4%), teicoplanin (19.4%) and vancomycin (16.7%). Enterococcus faecalis showed the least resistance to vancomycin (13.8%) and teicoplanin (27.7%). The high prevalence of resistant strains in this study can be attributed to misuse of drugs. This can be curtailed by stopping the sale of antibiotics across the counter and creating awareness among the populace by Government and Health Agencies on the consequences of unregulated antibiotic use

Trends of Multiple Drug Resistance in Salmonella Enterica Serovar Typhi in Lagos, Nigeria.

Background: The frequent treatment failures with empirical therapy observed in some hospitalized typhoid fever patients in the last decade is of great concerned to both public and private physicians owing to the wide spread and circulation of antibiotic resistant strains of S. typhiMethods: This study assessed the trends in antibiotic resistance in 235 Salmonella typhi stains isolated by standard procedures from blood and/stool samples of hospitalized patients from 1997 to 2003. All the isolates were subjected to antimicrobial susceptibility testing using the following antibiotics: chloramphenicol, Ampicillin, cotrimoxazole, tetracycline, nalidixic acid, ciprofloxacin and ofloxacin. Susceptibility and resistance were determined by standard methods.Results: From 1997 through 2003, 188 (80%) of 235 isolates were multiple drug resistant (MDR), chloramphenicol being the most resisted antibiotic (83.0%) followed by Ampicillin (81.7%). Only one strain was resistant to both ciprofloxacin and ofloxacin. Also the prevalence of chloramphenicol resistant isolates increased gradually from 72.4% in 1997 to 89.2% in 2003. Similar trends were recorded for other four antibiotics tested, even for single drug resistance S. typhi isolates. Our study confirmed increased in circulation of MDR-S. typhi isolates over relatively short period.Conclusion: We hereby suggest for a while the immediate stoppage of prescription of chloramphenicol and other first line antibiotics used in the treatment of typhoid fever in Nigeria. The use of more effective drugs such as ofloxacin and ciprofloxacin would go a long way in stemming the prevalence of persons with chronic infections as well as reducing the widespread of MDR-S. typhi strains in our environment, but our fear is that resistance is likely to develop unless these valuable drugs are used prudentl

Trends of Multiple Drug Resistance in Salmonella Enterica Serovar Typhi in Lagos, Nigeria.

Background: The frequent treatment failures with empirical therapy observed in some hospitalized typhoid fever patients in the last decade is of great concerned to both public and private physicians owing to the wide spread and circulation of antibiotic resistant strains of S. typhi Methods: This study assessed the trends in antibiotic resistance in 235 Salmonella typhi stains isolated by standard procedures from blood and/stool samples of hospitalized patients from 1997 to 2003. All the isolates were subjected to antimicrobial susceptibility testing using the following antibiotics: chloramphenicol, Ampicillin, cotrimoxazole, tetracycline, nalidixic acid, ciprofloxacin and ofloxacin. Susceptibility and resistance were determined by standard methods. Results: From 1997 through 2003, 188 (80%) of 235 isolates were multiple drug resistant (MDR), chloramphenicol being the most resisted antibiotic (83.0%) followed by Ampicillin (81.7%). Only one strain was resistant to both ciprofloxacin and ofloxacin. Also the prevalence of chloramphenicol resistant isolates increased gradually from 72.4% in 1997 to 89.2% in 2003. Similar trends were recorded for other four antibiotics tested, even for single drug resistance S. typhi isolates. Our study confirmed increased in circulation of MDR-S. typhi isolates over relatively short period. Conclusion: We hereby suggest for a while the immediate stoppage of prescription of chloramphenicol and other first line antibiotics used in the treatment of typhoid fever in Nigeria. The use of more effective drugs such as ofloxacin and ciprofloxacin would go a long way in stemming the prevalence of persons with chronic infections as well as reducing the widespread of MDR-S. typhi strains in our environment, but our fear is that resistance is likely to develop unless these valuable drugs are used prudently