Incidence and mechanism of antibiotic resistance of Streptococcus Agalactiae isolates from pregnant women and their babies at Dr George Mukhari Academic Hospital, Pretoria

BACKGROUND AND OBJECTIVES: Streptococcus agalactiae (Group B Streptococcus, GBS) is the leading cause of neonatal infections and deaths in human. It can also cause infections in pregnant women and non-pregnant adults. Penicillin and ampicillin are antibiotics of choice for the treatment of GBS infections. Erythromycin and clindamycin are used as alternative therapy in penicillin allergic patients, however resistance to these agents has been increasingly observed. This present study was undertaken to determine the colonization rate of GBS, susceptibility profile and the mechanism of antibiotic resistance in pregnant women and their babies at Dr. George Mukhari Academic Hospital in Pretoria. METHODS: Rectal and vaginal swabs were collected from pregnant women; ear and umbilical swabs from newborns over an 11 month period. Samples were cultured on selective media (CNA agar and Todd-Hewitt broth) and GBS positively identified using morphological and biochemical tests including Gram staining, hemolytic activity, catalase test, bile esculin, CAMP test and Latex agglutination test. The susceptibility testing was done using the Kirby-Bauer and E-test methods. The D-test method was used to determine the inducible clindamycin resistance. Multiplex PCR with were used to detect different genes coding for resistance. RESULTS: Out of the 413 patients evaluated, 128 (30.9%) were positive with GBS. All isolates were sensitive to penicillin and ampicillin. Erythromycin and clindamycin resistance was 21.1% and 17.2% respectively; of which 69% harbouring constitutive MLBB, 17.4% inducible MLSB. The alteration of ribosomal target encoded by ermB genes was the commonest mechanism of resistance observed in 55% of isolates, 38% of isolates had both ermB and linB genes and efflux pump mediated by mefA genes was detected in one of isolates. Conclusion: This study reaffirms the appropriateness of penicillin as the antibiotic of choice for treating GBS infection. However it raises the challenges of resistance to the macrolides and lincosamides. More GBS treatment options for penicillin allergic patients need to be researched.Health StudiesM. Sc. (Life Sciences (Microbiology)

Seroprevalence of hepatitis B and C virus infections among diabetic patients in Kisangani (North-eastern Democratic Republic of Congo)

Introduction: the link between diabetes mellitus and hepatitis B and C Virus infections has not yet been studied in the Democratic Republic of Congo, a country where diabetes mellitus is a growing disease and the prevalence of hepatitis B and C viruses infections is high. The aim of this study was to determine the seroprevalence of these viruses in diabetic patients. Methods: we conducted a descriptive cross-sectional study in diabetic subjects attending Kisangani University Clinics and General Hospitals of Kisangani City as well as the Diabetics Association of Oriental Province. The control group consisted of volunteer blood donors recruited from the Kisangani Provincial Blood Transfusion Center. Blood glucose was measured with the spectrophotometer; for hepatitis B and hepatitis C viruses serology, we used rapid test kits (Determine TM® HBsAg and Hexagon® HCV test) and ELISA if seropositivity by rapid tests. The analysis was done by SPSS software. Results: seroprevalence of hepatitis C virus in diabetics was 24.8% compared to 1.9% in volunteer blood donors (p = 0.0000); that of hepatitis B virus was 3.4% versus 3.5% in volunteer blood donors (p = 0.906). Hepatitis C virus infection was more common in type 2 diabetics (p = 0.006) and significantly associated with age of diabetic patients (p = 0.002). Conclusion: the seroprevalence of hepatitis C virus and not hepatitis B virus infection is significantly high in diabetic subjects, particularly type 2 diabetics, in the Democratic Republic of Congo and suggests systematic screening for this infection in any diabetic patient

Molecular characteristics and genotypic diversity of enterohaemorrhagic Escherichia coli O157:H7 isolates in Gauteng region, South Africa

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 is one of the major foodborne and waterborne pathogens causing severe diseases and outbreaks worldwide. There is scarcity of EHEC O157:H7 data in South Africa. This study was carried out to determine the molecular characteristics and genotypic diversity of EHEC O157:H7 isolates in the Gauteng region, South Africa. Samples were cultured on selective chromogenic media. Antibiotic susceptibility profile of isolates was determined using the VITEK®-2 automated system. Isolates were characterised using multiplex PCR assays and the genetic diversity was determined using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). A total of 520 samples of which 270 environmental water samples and 250 stool specimens were collected and analysed. Overall, EHEC O157:H7 was recovered from 2.3% (12/520) of samples collected. Environmental water samples and clinical stool specimens showed a prevalence of 4.07% (11/270) and 0.4% (1/250) respectively. Antibiotic susceptibility profile varied from isolates with full susceptibility to isolates with resistance to multiple antibiotics. Most resistance was detected to the penicillins, specifically ampicillin (7/12), amoxicillin (3/12) and piperacillin/Tazobactam (3/12) followed by one of the folate inhibitors, trimethoprim (3/12) and the carbapenems, imipenem and meropenem (2/12) each. Three isolates harboured a combination of Shiga-toxins (Stx)-2, intimin (eae) and enterohaemolysin (hlyA) genes, while two isolates harboured the Stx-1, Stx-2 and hlyA genes. The PFGE performed showed that EHEC O157:H7 isolates were genetically diverse, with two minor pulsotypes and eight singletons. The MLST analysis identified three sequence types (STs) (ST10, ST11 and ST1204) that have been previously reported associated with outbreaks. The STs identified in this study pose a potential public health risk to consumers of untreated environmental water and closed human contacts. There is necessity to enhance surveillance in reducing the propagation of this bacterium which is a public health problem.The National Health Laboratory Service (NHLS), National Research Foundation (NRF), Rand Water and University of Pretoria, South Africa.http://www.elsevier.com/locate/scitotenv2020-11-20hj2019Medical Microbiolog

Renal Abnormalities among Sickle Cell Disease Patients in a Poor Management Setting: A Survey in the Democratic Republic of the Congo.

peer reviewed[en] Background and objective: Sickle cell disease (SCD) is now a well-established cause of renal damage. In the northeast of the Democratic Republic of Congo (DRC), SCD is common. However, sickle cell nephropathy remains unstudied in this region. Thus, this study aimed to assess renal abnormalities in SCD patients in Kisangani (northeastern DRC). Methods: This cross-sectional study included 98 sickle cell patients selected from six health facilities in Kisangani and 89 healthy non-sickle cell subjects as the control group. Based on a survey form, a clinical examination and biological tests were performed to collect data related to the sex, age, weight, height, pressure, serum creatinine, serum uric acid, urinary albumin/creatinine ratio, and hemoglobin phenotype. We used a spectrophotometer to measure serum creatinine and uricemia, the sickle SCAN® device for hemoglobin phenotype, and an automatic multifunction analyzer for urine albumin/creatinine ratio. Data were entered into an Excel file and analyzed on SPSS 20.0. Results: The mean urine albumin-to-creatinine ratio was 11.79±9.03 mg/mmol in SCD patients, significantly higher than in AA (1.69±1.89 mg/mmol) and AS (2.97±4.46 mg/mmol) subjects. The decrease in glomerular filtration rate was more observed in SCD patients with hyperuricemia compared to those with normal uric acid levels. A significantly elevated prevalence of chronic kidney disease was observed among SCD patients (87.8%) compared to 23.8% in AS and 7.7% in AA subjects. Conclusions: This study highlighted that albuminuria and chronic kidney disease are common in SCD patients in Kisangani. More studies are needed to further document these complications

Occurrence of Hybrid Diarrhoeagenic Escherichia coli Associated with Multidrug Resistance in Environmental Water, Johannesburg, South Africa

This study was undertaken to determine the virulence and antibiotic resistance profiles of diarrhoeagenic Escherichia coli (DEC) in environmental waters of Johannesburg, South Africa. Samples were collected and cultured on selective media. An 11-plex PCR assay was used to differentiate five DEC, namely: enteroaggregative (EAEC), enterohaemorrhagic (EHEC), enteroinvasive (EIEC), enteropathogenic (EPEC) and enterotoxigenic (ETEC). The antibiotic resistance profile of isolates was determined using the VITEK®-2 automated system. The virulence profiles of 170 E. coli tested showed that 40% (68/170) were commensals and 60% (102/170) were pathogenic. EPEC had a prevalence of 19.2% (32/170), followed by ETEC 11.4% (19/170), EAEC 6% (10/170) and EHEC 3% (5/170). Hybrid DEC carrying a combination of simultaneously two and three pathogenic types was detected in twenty-eight and nine isolates, respectively. The antibiotic susceptibility testing showed isolates with multidrug resistance, including cefuroxime (100%), ceftazidime (86%), cefotaxime (81%) and cefepime (79%). This study highlighted the widespread occurrence of DEC and antibiotic resistance strains in the aquatic ecosystem of Johannesburg. The presence of hybrid pathotypes detected in this study is alarming and might lead to more severe diseases. There is a necessity to enhance surveillance in reducing the propagation of pathogenic and antibiotic-resistant strains in this area

Investigation of carbapenem-resistant Enterobacterales isolates at a tertiary laboratory in Pretoria, South Africa

This study aimed to investigate phenotypic and genotypic characteristics of carbapenem-resistant Enterobacterales isolates (CRE) at a tertiary laboratory in South Africa. A total of 99 CRE isolates were collected between 2019 and 2021. Carbapenemase production was tested using modified carbapenem inhibitory method. Colistin susceptibility testing was performed using the ComASPTM Colistin broth microdilution method. Conventional PCR assays were conducted for detection of mcr-1 gene and common carbapenemase genes (blaVIM, blaNDM, blaIMP, blaKPC, blaOXA-23, blaOXA-51 and blaOXA-48). Rep-PCR assay was conducted to determine the genetic relatedness of the study isolates. Majority of the isolates were Klebsiella pneumoniae (83%). Carbapenem resistant K. pneumoniae cluster was observed from ICU and surgical ward samples. Colistin resistance was observed in 13% (12/93) of the isolates namely, in 11 K. pneumoniae and one Enterobacter cloacae. The blaOXA-48 (65%) was the most prevalent gene detected followed by blaNDM (25%) and blaVIM (22%). Several K. pneumoniae isolates concomitantly carried multiple carbapenemase genes with one isolate carry up to 5 five genes blaVIM, blaNDM, blaOXA-48, blaOXA23 and blaOXA-51. The mcr-1 gene was not detected in the isolates. Rep-PCR assay showed that most isolates matched cluster A (50%). The high prevalence of blaOXA-48, blaNDM and emerging colistin resistant isolates is of concern for patient management at this institution and needs close monitoring. RepPCR is a valuable tool in establishing infection clusters in resource-limited settings