Auxotypes, serovars, and trends of antimicrobial resistance of Neisseria gonorrhoeae in Kigali, Rwanda (1985-93)

Five-Year Antimicrobial Susceptibility Trends Among Bacterial Isolates from a Tertiary Health-Care Facility in Kigali, Rwanda

Antimicrobial resistance (AMR) is a global public health threat. There is limited information from Rwanda on AMR trends. This longitudinal study aimed to describe temporal trends of antibiotic susceptibility among common bacteria. We collated the antimicrobial susceptibility results of bacteria cultured from clinical specimens collected from inpatients and outpatients and submitted to the microbiology laboratory at King Faisal Hospital, Kigali, Rwanda, from January 1, 2009, to December 31, 2013. Differences in antimicrobial susceptibility between the first and fifth year of the study for each bacterial species was assessed using χ² test. Of 5,296 isolates collected, 46.7% were Escherichia coli, 18.4% were Klebsiella spp., 5.9% were Acinetobacter spp., 7.1% were Pseudomonas spp., 11.7% were Staphylococcus aureus, and 10.3% were Enterococcus spp. Colistin and imipenem had greatest activity against gram-negative bacteria. Acinetobacter spp. showed the greatest resistance profile to antimicrobials tested, relative to other gram-negative bacteria. Vancomycin retained excellent activity against S. aureus and Enterococcus species (average susceptibility was 100% and 99.4%, respectively). Trend analysis determined that resistance to imipenem increased significantly among Klebsiella, E. coli, Pseudomonas, and Acinetobacter isolates; there was also rising resistance to colistin among E. coli and Pseudomonas species. Only E. coli demonstrated increased resistance to gentamicin. For gram-positive pathogens, vancomycin susceptibility increased over time for Enterococcus species, but was unchanged for S. aureus Our data suggest that resistance to imipenem and colistin are rising among gram-negative bacteria in Rwanda. Proper infection control practices and antimicrobial stewardship will be important to address this emerging threat.

Antimicrobial drug resistance among clinically relevant bacterial isolates in sub-Saharan Africa: a systematic review

BACKGROUND

Little is known about the prevalence of antimicrobial resistance (AMR) amongst bacterial pathogens in sub-Saharan Africa (sSA), despite calls for continent-wide surveillance to inform empirical treatment guidelines.

METHODS

We searched PubMed and additional databases for susceptibility data of key pathogens for surveillance, published between 1990 and 2013. Extracted data were standardized to a prevalence of resistance in populations of isolates and reported by clinical syndrome, microorganism, relevant antimicrobial drugs and region.

RESULTS

We identified 2005 publications, of which 190 were analysed. Studies predominantly originated from east sSA (61%), were hospital based (60%), were from an urban setting (73%) and reported on isolates from patients with a febrile illness (42%). Quality procedures for susceptibility testing were described in <50% of studies. Median prevalence (MP) of resistance to chloramphenicol in Enterobacteriaceae, isolated from patients with a febrile illness, ranged between 31.0% and 94.2%, whilst MP of resistance to third-generation cephalosporins ranged between 0.0% and 46.5%. MP of resistance to nalidixic acid in Salmonella enterica Typhi ranged between 15.4% and 43.2%. The limited number of studies providing prevalence data on AMR in Gram-positive pathogens or in pathogens isolated from patients with a respiratory tract infection, meningitis, urinary tract infection or hospital-acquired infection suggested high prevalence of resistance to chloramphenicol, trimethoprim/sulfamethoxazole and tetracycline and low prevalence to third-generation cephalosporins and fluoroquinolones.

CONCLUSIONS

Our results indicate high prevalence of AMR in clinical bacterial isolates to antimicrobial drugs commonly used in sSA. Enhanced approaches for AMR surveillance are needed to support empirical therapy in sSA.

Plasmid-mediated penicillin and tetracycline resistance among Neisseria gonorrhoeae isolates in South Africa: prevalence, detection and typing using a novel molecular assay

BACKGROUND

To detect and type plasmids responsible for penicillin and tetracycline resistance in Neisseria gonorrhoeae isolates using a novel duplex polymerase chain reaction (PCR) assay.

METHODS

A duplex PCR assay, to detect and type penicillinase-producing N. gonorrhoeae (PPNG), and plasmid-mediated tetracycline resistant N. gonorrhoeae (TRNG), was developed on the basis of published single assays. Gonococcal Isolate Surveillance Project control strains were used in assay development and then 209 consecutive N. gonorrhoeae isolates, collected from men with urethral discharge in 2008, were tested. Controls included Asia, Africa, and Toronto β-lactamase plasmids, as well as American and Dutch TRNG plasmids. PCR amplicons were detected using an Agilent 2100 Bioanalyzer. Minimum inhibitory concentrations (MIC) were determined with E tests. Penicillinase production was detected using Nitrocefin solution.

RESULTS

Among 209 gonococcal isolates, 54 (25.8%) PPNG and 154 (73.3%) TRNG were detected. The MIC50 and MIC90 values were determined for penicillin (0.19 and 32 mg/L) and tetracycline (6 and 16 mg/L). The assay detected the Africa-type (35.2%), the Toronto-type (44.4%), and a new type (20.3%) of β-lactamase plasmid. The American-type TRNG plasmid was 3-fold more frequent as compared with the Dutch-type. Although there was no overall association between the detection of PPNG and TRNG plasmids, only American type TRNG contained β-lactamase-encoding plasmids (P < 0.0001).

CONCLUSIONS

The prevalence of plasmid-mediated resistance to tetracycline, and to a lesser extent penicillin, is high and neither drug is likely to have any future role in the treatment of gonorrhoea in South Africa. A novel β-lactamase plasmid was detected during the study and requires further characterization.

Travel and sexually transmitted infections

Increasing population mobility and increasing frequency and variety of sexually transmitted infections (STI) are closely linked around the globe. Although all mobile populations are at increased risk for acquiring STIs, international travelers are the focus of this review. Several aspects of travel such as opportunity, isolation, and the desire for unique experiences all enhance the likelihood of casual sexual experiences while abroad. The situational loss of inhibition of travel can be markedly enhanced by alcohol and drugs. Several of the most important elements of the complex interaction between travel and STIs are discussed.

Antimicrobial resistance in developing countries. Part I: recent trends and current status

The global problem of antimicrobial resistance is particularly pressing in developing countries, where the infectious disease burden is high and cost constraints prevent the widespread application of newer, more expensive agents. Gastrointestinal, respiratory, sexually transmitted, and nosocomial infections are leading causes of disease and death in the developing world, and management of all these conditions has been critically compromised by the appearance and rapid spread of resistance. In this first part of the review, we have summarised the present state of resistance in these infections from the available data. Even though surveillance of resistance in many developing countries is suboptimal, the general picture is one of accelerating rates of resistance spurred by antimicrobial misuse and shortfalls in infection control and public health. Reservoirs for resistance may be present in healthy human and animal populations. Considerable economic and health burdens emanate from bacterial resistance, and research is needed to accurately quantify the problem and propose and evaluate practicable solutions. In part II, to be published next month, we will review potential containment strategies that could address this burgeoning problem.

Antimicrobial susceptibilities of Neisseria gonorrhoeae strains isolated in Java, Indonesia

BACKGROUND

Despite the rapid spread of antibiotic resistance in gonococci all over Southeast Asia, there is only limited surveillance for antibiotic susceptibility in Indonesia.

GOAL

This study was undertaken to determine the frequency and diversity of antimicrobial resistance in gonococcal isolates from cohorts of female commercial sex workers in Bandung and Jakarta, Indonesia, and to characterize the Tet M plasmid among the tetracycline-resistant strains N gonorrhoeae.

STUDY DESIGN

The antimicrobial susceptibility of 267 strains (85 strains from Bandung and 182 from Jakarta) to penicillin, spectinomycin, tetracycline, ciprofloxacin, cefotaxime, thiamphenicol, kanamycin, azithromycin, and trimethoprim-sulfamethoxazole (TMP-SMZ) was determined by agar dilution. Typing of the Tet M plasmid in tetracycline-resistant isolates was performed by PCR.

RESULTS

Prevalence of penicillin and tetracycline resistance was extremely high: 60.0% of the isolates from Bandung and 70.9% of the isolates from Jakarta were resistant to penicillin. Of these, 60.0% and 62.1%, respectively, were penicillinase-producing N gonorrhoeae (PPNG). All the isolates from Bandung and 98.4% from Jakarta were resistant to tetracycline. All tetracycline-resistant isolates from Bandung and 97.8% from Jakarta carried a PCR fragment characteristic of the "Dutch" type Tet M plasmid. One isolate from Jakarta showed chromosomal resistance to tetracycline (0.6%). Chromosomal resistance to thiamphenicol (MIC, >/=2.0 microg/ml) was significantly higher in Jakarta than in Bandung (P < 0.05). All gonococcal isolates were susceptible to kanamycin, spectinomycin, cefotaxime, ciprofloxacin, and azithromycin.

CONCLUSION

Spectinomycin, fluoroquinolones, and azithromycin are still useful primary drugs for treatment of gonococcal infections in Indonesia. Continued surveillance of antimicrobial susceptibility should be part of gonorrhea control in Indonesia.

Surveillance of antibiotic resistance of Neisseria gonorrhoeae isolates in China, 1993-1998

BACKGROUND

The prevalence of sexually transmitted diseases (STDs) has been increasing in China since the 1980s. Because gonorrhea is the most frequently reported STD there, information on the antimicrobial susceptibility of Neisseria gonorrhoeae will aid in its control.

GOAL

To investigate the antimicrobial susceptibility of N gonorrhoeae isolates in China and to provide data for formulation of treatment guidelines and control policies.

METHODS

The agar dilution technique was used to determine antimicrobial susceptibility, and acidimetric method was used to test for penicillinase-producing N gonorrhoeae.

RESULTS

A total of 3186 gonococcal isolates were tested during the 6-year study period. The rate of resistance to penicillin was 66.70%; 8.14% of isolates were penicillinase-producing N gonorrhoeae. The percentage of tetracycline-resistant isolates was 92.03%, and that of highly tetracycline-resistant isolates was 4.65%. The rate of resistance to ciprofloxacin was also relatively high (34.25%). The rates of resistance to spectinomycin and ceftriaxone were 0.44% and 0.57%.

CONCLUSIONS

The gonococcal isolates in China are relatively highly resistant to penicillin, tetracycline, and ciprofloxacin, but most of them are still susceptible to spectinomycin and ceftriaxone. Standardized treatment of gonorrhea is needed to prevent further spread of resistant gonococcal strains.

Antimicrobial susceptibilities of Neisseria gonorrhoeae in Kigali, Rwanda, and trends of resistance between 1986 and 2000

BACKGROUND

Plasmid-mediated and chromosomal-mediated resistance of Neisseria gonorrhoeae to penicillin, tetracycline, thiamphenicol, and trimethoprim-sulfamethoxazole has spread dramatically in Africa. Monitoring of antimicrobial susceptibility is a key element in the control of sexually transmitted diseases.

GOAL

To document antimicrobial susceptibilities of gonococci isolated during the past 15 years in Kigali, Rwanda.

STUDY DESIGN

Minimal inhibitory concentrations of recently collected gonococcal isolates of eight antimicrobials were determined. The results were compared with data collected for isolates obtained since 1986.

RESULTS

In 1986, 35% of the gonococcal isolates were penicillinase-producing N gonorrhoeae. Tetracycline-resistant N gonorrhoeae appeared in 1989. The prevalence of penicillinase-producing N gonorrhoeae and tetracycline-resistant N gonorrhoeae increased significantly to 70.5% and 89.2%, respectively. Chromosomal resistance to penicillin, tetracycline, and thiamphenicol increased temporarily, then decreased significantly. Chromosomal resistance to trimethoprim-sulfamethoxazole appeared in 1988 and increased to 21.6%. All the isolates were susceptible to ceftriaxone, ciprofloxacin, spectinomycin, and kanamycin.

CONCLUSIONS

This study illustrated the rapidly increasing frequencies of penicillinase-producing N gonorrhoeae and tetracycline-resistant N gonorrhoeae. Chromosomal resistance to thiamphenicol and trimethoprim-sulfamethoxazole excludes these drugs as alternative treatment. Programs for antimicrobial susceptibility surveillance of N gonorrhoeae should urgently be established in Africa.