Prevalence and antimicrobial resistance of coagulase negative staphylococci clinical isolates from Ethiopia: a meta-analysis

Assessing bacterial prevalence and resistance in paediatric meningitis: safeguarding the central nervous system

Introduction

Paediatric bacterial meningitis (PBM) represents a major contributor to childhood morbidity and mortality globally, with heightened susceptibility in low- and middle-income nations where antimicrobial resistance (AMR) is highly prevalent. Pakistan exemplifies this setting, with widespread antibiotic overuse driving AMR expansion. Thus, expediting PBM diagnosis and targeted antibiotic therapy is imperative yet challenged by the dynamic local epidemiology. This study aimed to delineate the recent bacterial etiologies and AMR profiles of PBM from a major Pakistani diagnostics laboratory to inform empirical treatment.

Materials and methods

This prospective observational investigation evaluated PBM epidemiology in patients under 18 years old admitted to the study hospital. Standard cerebrospinal fluid analysis identified bacterial pathogens and antibiotic susceptibility patterns.

Results

Among 171 PBM cases, 152 (88.9%) had bacterial isolates confirmed via culture. The cohort was 42.7% male with a mean age of 3 months. The most prevalent pathogens among infants younger than 3 months were Escherichia coli, Enterococcus faecium, and Staphylococcus epidermidis, contrasting with S. epidermidis, Streptococcus pneumoniae, and Staphylococcus hominis predominating in older children. Staphylococcal isolates exhibited considerable penicillin and erythromycin resistance but maintained vancomycin and linezolid susceptibility. Other resistance patterns varied.

Conclusion

These findings highlight the pressing threat of paediatric AMR in Pakistan, underscoring the need for vigilant AMR surveillance and judicious antimicrobial use. This study provides a reference to current PBM epidemiology to guide context-specific empirical therapy.

Antiseptics and mupirocin resistance in clinical, environmental, and colonizing coagulase negative Staphylococcus isolates

BACKGROUND

Coagulase-Negative Staphylococci (CoNS) are opportunistic and nosocomial pathogens. The excessive use of antimicrobial agents, including antiseptics, represents one of the world's major public health problems. This study aimed to test the susceptibility of CoNS to antiseptics.

METHODS

Out of 250 specimens collected from different sections of the hospital, 55 samples were identified as CoNS, categorized into three groups based on their sources: environmental samples (n = 32), healthcare worker carriers samples (n = 14), and clinical infection samples (n = 9). Isolates were examined for susceptibility to antibiotics and antiseptics, such as benzalkonium chloride (BC), cetyltrimethylammonium bromide (CTAB), and chlorhexidine digluconate (CHDG). Mupirocin and antiseptic resistance genes, as well as the mecA gene, were detected using polymerase chain reaction. CoNS isolates with notable resistance to antiseptics and antibiotics were identified using the API-Staph system.

RESULTS

A high frequency of multidrug resistance among CoNS clinical infection isolates was observed. Approximately half of the CoNS isolates from healthcare workers were susceptible to CHDG, but 93% were resistant to BC and CTAB. The frequency of antiseptics and antibiotics resistance genes in CoNS isolates was as follows: qacA/B (51/55; 92.7%), smr (22/55; 40.0%), qacG (1/55; 1.8%), qacH (6/55; 10.9%), qacJ (4/55; 7.3%), mecA (35/55; 63.6%), mupB (10/55; 18.2%), and mupA (7/55; 12.7%). A significant difference in the prevalence of smr gene and qacJ genes between CoNS isolates from healthcare workers and other isolates was reported (P value = 0.032 and ˂0.001, respectively). Four different CoNS species; S. epidermidis, S. chromogene, S. haemolyticus, and S. hominis, were identified by API.

CONCLUSIONS

CoNS isolates colonizing healthcare workers showed a high prevalence of antiseptic resistance genes, while clinical infection samples were more resistant to antibiotics. CHDG demonstrated greater efficacy than BC and CTAB in our hospital.

Analysis of the Presence of the Virulence and Regulation Genes from Staphylococcus aureus (S. aureus) in Coagulase Negative Staphylococci and the Influence of the Staphylococcal Cross-Talk on Their Functions

Coagulase-negative staphylococci (CoNS) are increasingly becoming a public health issue worldwide due to their growing resistance to antibiotics and common involvement in complications related to invasive surgical procedures, and nosocomial and urinary tract infections. Their behavior either as a commensal or a pathogen is a result of strict regulation of colonization and virulence factors. Although functionality of virulence factors and processes involved in their regulation are quite well understood in S. aureus, little is known about them in CoNS species. Therefore, the aim of our studies was to check if clinical CoNS strains may contain virulence factors and genes involved in resistance to methicillin, that are homologous to S. aureus. Moreover, we checked the presence of elements responsible for regulation of genes that encode virulence factors typical for S. aureus in tested isolates. We also investigated whether the regulation factors produced by one CoNS isolate can affect virulence activity of other strains by co-incubation of tested isolates with supernatant from other isolates. Our studies confirmed the presence of virulence factor and regulatory genes attributed to S. aureus in CoNS isolates and indicated that one strain with an active agr gene is able to affect biofilm formation and δ-toxin activity of strains with inactive agr genes. The cognition of prevalence and regulation of virulence factors as well as antibiotic resistance of CoNS isolates is important for better control and treatment of CoNS infections.

Molecular Characterisation of Antibiotic Resistance in Staphylococcus haemolyticus Isolates from Chennai, South India

Staphylococcus haemolyticus is a highly resistant opportunistic pathogen having close genomic relatedness with other virulent species of staphylococci. However, compared to Staphylococcus aureus and Staphylococcus epidermidis, little is known about the resistance genes of S. haemolyticus. The purpose of this study was to characterise antibiotic resistance genes in S. haemolyticus isolates. Standard microbiological techniques were used to identify and confirm 104 S. haemolyticus isolates included in the study. Antibiotic susceptibility testing and D-test were performed, followed by PCR amplification of various resistance determinants (mecA, ermA, ermC, msrA, aac(6′)-Ie-aph(2″), ant(4′)-Ia,aph(3′)-IIIa, tetK, tetM, dfrA, fusB, fusC, fusD and mupA). Methicillin resistance was observed in 93.3% of study isolates. The maximum number of isolates showed resistance to erythromycin (n=79, 76%), followed by ciprofloxacin (n=66, 63.5%) and cotrimoxazole (n=58, 55.8%). In the D-test, 8 isolates showed inducible (iMLSB) and 11 showed constitutive (cMLSB) resistance. Among the resistance determinants, mecA gene (93.3%) was the most prevalent, followed by dfrA (50.5%). Furthermore, aac(6’)-Ie-aph(2’’) and aph(3’)-IIIa combination was observed in 26.9% of isolates, and aac(6’)-Ie-aph(2’’) alone was present in 3.8% of isolates. Among the study isolates, 17.3% exhibited tetK gene, whereas only 1% exhibited tetM; a combination of tetK and tetM was observed in one isolate. The fusB and fusC were present in 11.5% of isolates, and 12.5% of the isolates were positive for mupA. In conclusion, the present study underlines the concern of increasing antibiotic resistance among S. haemolyticus isolates. Avoiding misuse/overuse of antibiotics along with continuous surveillance programs can reduce the spread of antibiotic resistance.

Detection of Resistant and Enterotoxigenic Strains of Staphylococcus warneri Isolated from Food of Animal Origin

The topic of this work is the detection of antimicrobial resistance to Staphylococcus warneri strains and the genes encoding staphylococcal enterotoxins. It is considered a potential pathogen that can cause various—mostly inflammatory—diseases in immunosuppressed patients. The experimental part of the paper deals with the isolation of individual isolates from meat samples of Oryctolagus cuniculus, Oncorhynchus mykiss, Scomber scombrus, chicken thigh, beef thigh muscle, pork thigh muscle, and bryndza cheese. In total, 45 isolates were obtained and subjected to phenotypic (plasma coagulase activity, nuclease, pigment, hemolysis, lecithinase, and lipase production) and genotypic analyses to confirm the presence of the S. warneri species. The presence of genes encoding staphylococcal enterotoxins A (three isolates) and D (six isolates) was determined by PCR. Using the Miditech system, the minimum inhibitory concentration for various antibiotics or antibiotics combinations was determined, namely for ampicillin; ampicillin + sulbactam; oxacillin; cefoxitin; piperacillin + tazobactam; erythromycin; clindamycin; linezolid; rifampicin; gentamicin; teicoplanin; vancomycin; trimethoprim; chloramphenicol; tigecycline; moxifloxacin; ciprofloxacin; tetracycline; trimethoprim + sulfonamide; and nitrofurantoin. Resistance to ciprofloxacin and tetracycline was most common (73%). At the same time, out of a total of 45 isolates, 22% of the isolates were confirmed as multi-resistant. Isolates that showed phenotypic resistance to β-lactam antibiotics were subjected to mecA gene detection by PCR.

Vancomycin-resistant enterococci and coagulase-negative staphylococci prevalence among patients attending at Felege Hiwot Comprehensive Specialized Hospital, Bahir Dar, Ethiopia

Background

Vancomycin resistant enterococci (VRE) and vancomycin resistance coagulase negative staphylococci (VRCoNS) are common pathogens causing difficult to treat health care associated infections (HAI). Hence, the World Health Organization listed VRE as one of the high priority pathogens for new antibiotic discovery and antimicrobial resistance surveillance. Despite this, data on the prevalence of VRE and VRCoNS in Ethiopia is scarce. Thus, the present study determined prevalence of VRE and VRCoNS among patients attending Felege-Hiwot comprehensive specialized hospital, Ethiopia.

Methods

A hospital based cross-sectional study was conducted on 384 patients selected conveniently from February to March 2020. Data on demographic and clinical variables were collected using a structured questionnaire by face-to-face interview. Simultaneously urine, venous blood and wound swab were collected and processed following standard bacteriological technique. Antimicrobial susceptibility test was performed by minimum inhibitory concentration method using E-test for vancomycin and Kirby-Bauer disc diffusion method for other classes of antibiotics. Data was entered and analyzed using SPSS version 23. Logistic regression was performed to identify factors associated with VRE infection. P. value < 0.05 was considered as statistically significant.

Results

The prevalence of enterococci and CoNS were 6.8% and 12% respectively. The prevalence of VRE was 34.61% (9/26), while all CoNS (46 isolates) were susceptible to vancomycin. The majority (66.7%) of VRE was isolated from blood samples. Furthermore all VRE (100%), 58.8% of vancomycin susceptible enterococci and 45.7% of CoNS were multidrug resistant (MDR). Having educational level of secondary school and below (AOR = 12.80, CI = 1.149–142.5), previous exposure to catheterization (AOR = 56.0, CI = 4.331–724.0) and previous antibiotic use practice (AOR = 26.25, CI = 3.041–226.2) were a significant associated explanatory factor for VRE infection.

Conclusions

The prevalence of vancomycin resistance enterococci, which is also multidrug resistant, was significantly high. Though no vancomycin resistance CoNS detected, the MDR level of CoNS was high. Thus to limit enterococci and CoNS infections and MDR development, focused infection prevention measures should be implemented.

Prevalence and antimicrobial resistance patterns of bacteria isolated from cerebrospinal fluid among children with bacterial meningitis in China from 2016 to 2018: a multicenter retrospective study

Background

Pediatric bacterial meningitis (PBM) remains a devastating disease that causes substantial neurological morbidity and mortality worldwide. However, there are few large-scale studies on the pathogens causing PBM and their antimicrobial resistance (AMR) patterns in China. The present multicenter survey summarized the features of the etiological agents of PBM and characterized their AMR patterns.

Methods

Patients diagnosed with PBM were enrolled retrospectively at 13 children’s hospitals in China from 2016 to 2018 and were screened based on a review of cerebrospinal fluid (CSF) microbiology results. Demographic characteristics, the causative organisms and their AMR patterns were systematically analyzed.

Results

Overall, 1193 CSF bacterial isolates from 1142 patients with PBM were obtained. The three leading pathogens causing PBM were Staphylococcus epidermidis (16.5%), Escherichia coli (12.4%) and Streptococcus pneumoniae (10.6%). In infants under 3 months of age, the top 3 pathogens were E. coli (116/523; 22.2%), Enterococcus faecium (75/523; 14.3%), and S. epidermidis (57/523; 10.9%). However, in children more than 3 months of age, the top 3 pathogens were S. epidermidis (140/670; 20.9%), S. pneumoniae (117/670; 17.5%), and Staphylococcus hominis (57/670; 8.5%). More than 93.0% of E. coli isolates were sensitive to cefoxitin, piperacillin/tazobactam, cefoperazone/sulbactam, amikacin and carbapenems, and the resistance rates to ceftriaxone, cefotaxime and ceftazidime were 49.4%, 49.2% and 26.4%, respectively. From 2016 to 2018, the proportion of methicillin-resistant coagulase-negative Staphylococcus isolates (MRCoNS) declined from 80.5 to 72.3%, and the frequency of penicillin-resistant S. pneumoniae isolates increased from 75.0 to 87.5%. The proportion of extended-spectrum β-lactamase (ESBL)-producing E. coli fluctuated between 44.4 and 49.2%, and the detection rate of ESBL production in Klebsiella pneumoniae ranged from 55.6 to 88.9%. The resistance of E. coli strains to carbapenems was 5.0%, but the overall prevalence of carbapenem-resistant K. pneumoniae (CRKP) was high (54.5%).

Conclusions

S. epidermidis, E. coli and S. pneumoniae were the predominant pathogens causing PBM in Chinese patients. The distribution of PBM causative organisms varied by age. The resistance of CoNS to methicillin and the high incidence of ESBL production among E. coli and K. pneumoniae isolates were concerning. CRKP poses a critical challenge for the treatment of PBM.

Guideline Recommendations for Empirical Antimicrobial Therapy: An Appraisal of Research Evidence for Clinical Decision-Making in Ethiopia

INTRODUCTION

The rapid spread of drug resistance is forcing standard treatment guidelines (STGs) to become more appropriate with due consideration of the evidence on the antimicrobial resistance (AMR) situation in Ethiopia. Therefore, we aimed to assess the local AMR recommendations in the STGs for empirical antibacterial prescriptions for the five common infectious syndromes. We also determined the quality of AMR reviews conducted in the country.

METHODS

We conducted a review of the STGs used in the health centers, general hospitals, and primary hospitals in Ethiopia and assessed the AMR recommendations in STGs for empirical antibacterial prescriptions for community-acquired pneumonia (CAP), urinary tract infection (UTI), tonsillopharyngitis, acute otitis media (AOM), and bacterial dysentery. Next, we performed an overview of AMR reviews published in Ethiopia. We used the MEDLINE/PubMed, Embase, Cochrane Library, and Google Scholar databases to identify AMR reviews. The review characteristics were extracted. We also evaluated the quality of each included AMR review using a measurement tool to assess the systematic review scale (AMSTAR 2).

RESULTS

A total of 6 STGs and 12 AMR reviews conducted in the country were included. The choice of empirical antibacterials for similar infectious syndromes (and editions) was comparable across the three levels of the health care system. None of the STGs evaluated included the local AMR recommendations for empirical antibacterial prescriptions for five common infectious syndromes. Of all the AMR reviews included, 75% had low and below methodologic quality, and none had a high-quality score using the AMSTAR 2 tool.

CONCLUSION

Standard treatment guidelines did not consider local AMR recommendations for empirically prescribing antibacterials for common infectious syndromes. The AMR reviews published in the country produced poor methodologic quality evidence for clinical applications. This highlights the need to improve the methodologic quality to provide the best available evidence for clinical decision-making and curb the ongoing AMR in Ethiopia.

TRIAL REGISTRATION

Retrospectively registered (15/07/2020).

The species distribution, antimicrobial resistance and risk factors for poor outcome of coagulase-negative staphylococci bacteraemia in China

Objective

Coagulase-negative staphylococci (CoNS) are one of the major opportunistic pathogens and the incidence of CoNS bacteraemia is increasing. However, most of the CoNS-positive blood cultures are contaminants rather than true CoNS bacteraemia. In order to minimize contamination, we defined true CoNS bacteraemia as the patient that has two or more identical CoNS-positive blood cultures drawn within 48 h in this study and the objective of this study was to analyse the species distribution and antibiotic resistance and to identify risk factors for 30-day mortality of the true CoNS-bacteraemia.

Method

By reviewing the electronic medical database, this study retrospectively analysed patients diagnosed as CoNS bacteraemia by blood cultures in a comprehensive tertiary care hospital in China from January 1, 2014, to December 31, 2017.

Result

A total of 1241 patients with 1562 episodes of CoNS-positive blood cultures were recorded in the database but only 157 patients were finally diagnosed as true CoNS bacteraemia after contaminants were excluded. All these 157 patients (12.7%, 157/1241) had bacteraemia-related clinical symptoms. Among the 157 patients, the most common species were Staphylococcus hominis (40.8%), Staphylococcus epidermidis (36.3%) and Staphylococcus capitis (11.5%). The antimicrobial susceptibility tests showed that all CoNS had a high rate of resistance to penicillin (94.9%), oxacillin (93.6%) and erythromycin (92.4%). Resistance to gentamicin (22.3%) and rifampicin (10.8%) was low, and none of the bacteria were resistant to vancomycin or linezolid. The 30-day mortality of patients with CoNS bacteraemia was up to 12.7% (20/157), and the multivariate logistics regression analysis showed that chronic renal failure (OR 5.9, 95% CI 1.6–21.5, p = 0.007) and chronic liver failure (OR 4.0, 95% CI 1.2–13.1, p = 0.024) were both the significant independent risk factors for the 30-day mortality of CoNS bacteraemia.

Conclusion

Staphylococcus hominis and Staphylococcus epidermidis were the most common species in CoNS bacteraemia. All CoNS had high multi-drug resistance, but gentamicin and rifampicin had a relatively lower resistance and could be considered as alternative antibiotics for anti-CoNS bacteraemia in addition to vancomycin and linezolid. Additionally, patients with chronic renal failure or chronic liver failure have a higher 30-day mortality after the onset of CoNS bacteraemia.

Exploring bacterial resistance in Northern Oman, a foundation for implementing evidence-based antimicrobial stewardship program

BACKGROUND

Increasing rate of resistant infections is a challenge to healthcare negatively impacting therapeutic and financial outcomes. Targeted antimicrobial stewardship interventions are needed to counteract this global crisis. On large scale, we sought to identify the prevalence of resistant pathogens and their susceptibility pattern in Northern Oman.

MATERIAL AND METHOD

Retrospective analysis of all isolates processed by Suhar Hospital microbiology laboratory between Jan1st, 2016 and Dec31st, 2017. Organism identification, susceptibility and phenotyping were performed following CLSI standards and duplicate isolates were excluded. Pertinent microbiological data were collected and analyzed.

RESULTS

Of 15,733 samples included, Gram-negative bacteria predominate by 67.76%, Gram-positive (29%) and Candida species (2.63%). Frequently isolated Gram-negative bacteria were Escherichia coli (32.39%), Pseudomonas aeruginosa (22.16%), Klebsiellapneumoniae (19.97%) and Acinetobacter baumannii (5.22%), there was virtually no resistance to colistin and tigecycline, while a growing resistance toward ciprofloxacin and meropenem was observed. Resistant E. coli and K. pneumoniae were isolated from bloodstream infection (12%). While Gram-positives were MSSA (27.23%), Streptococcus agalactiae (25.36%), MRSA (16.10%) and CoNS (12.1 %), they were almost universally susceptible to daptomycin and linezolid with low resistance (8˜20%) to clindamycin. Approximately, 50% of Staphylococci (MRSA and CoNS) required vancomycin treatment.

CONCLUSION

Study findings should guide targeted stewardship interventions to optimize antibiotic prescriptions. Empirical treatment options should be revised, drug-bug match therapy instituted promptly and newer agents considered. Prescribing restriction of formulary antimicrobials that still retain their activity towards bugs - like colistin, linezolid and tigecycline- is a mandatory action. Review empiric use of ciprofloxacin and meropenem to counteract growing resistance.