Multi-drug resistance in Streptococcus pneumoniae among children in rural Vietnam more than doubled from 1999 to 2014

Detection of Macrolide-Resistant Streptococcus pneumoniae Genes and Its Clinical Outcomes in a Tertiary Teaching Hospital in Malaysia

Background

Streptococcus pneumoniae is one of the leading causes of mortality and morbidity worldwide. The dramatic increase in in-vitro resistance of antimicrobial agents, particularly beta-lactams and macrolides, makes pneumococcal infections difficult to treat. The aim of this study was to describe the drug resistance rate, assess the prevalence of macrolide-resistant genes and review the clinical complications of pneumococcal infections among patients presented to Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia.

Methods

This is a descriptive cross-sectional study. All S. pneumoniae isolates collected from clinical specimens within a 1-year period were subjected to selected antimicrobial susceptibility testing using E-test strips. Polymerase chain reaction (PCR) analysis was conducted to detect macrolide-resistant determinants. The patient's clinical data were obtained from clinical notes.

Results

A total of 113 patients with a positive growth of S. pneumoniae were included in the study. The most common predisposing factors among them were bronchopulmonary diseases (15.9%). The penicillin-resistant rate was 7.1%, with minimal inhibitory concentration (MIC) ranging between 0.012 μg/mL and >32 μg/mL, and the erythromycin-resistant rate was 26.5%, with a MIC range of 0.03 μg/mL-> 256 μg/mL. Most of the erythromycin-resistant isolates were found to have the mef(A) gene (50.4%) and the erm(B) gene (20%); 16.7% had a combination of genes mef(A) and erm(B), and 13.3% had none of the two genes. Community-acquired pneumonia is the predominant type of pneumococcal infection. There was no significant association between the presence of macrolide resistance determinants and mortality (P = 0.837) or complications (P > 0.999 for empyema and cardiac complication; P = 0.135 for subdural abscess).

Conclusion

The majority of erythromycin-resistant isolates were found to have the mef(A) gene, followed by the erm(B) gene and a combination of genes mef(A) and erm(B).

Global trends in non-susceptibility rates of Streptococcus pneumoniae isolates to ceftriaxone: Data from the antimicrobial testing leadership and surveillance (ATLAS) programme, 2016-21

To understand the global changes in non-susceptibility rates of Streptococcus pneumoniae to ceftriaxone, we conducted a study using the Antimicrobial Testing Leadership and Surveillance database. A total of 15,717 S. pneumoniae isolates were collected from 2016 to 2021. The minimum inhibitory concentrations (MICs) were determined using broth microdilution. The overall susceptibility rates of S. pneumoniae isolates to penicillin, ceftriaxone and ceftaroline were 63.4%, 94.0% and 99.6%, respectively. The geometric mean of MICs and MIC50/MIC90 values of ceftriaxone were higher in Asia than in other continents. China (33.9%), South Korea (33.8%) and Taiwan (27.6%) had the highest ceftriaxone non-susceptibility rates, followed by Turkey, India, Brazil, Malaysia, South Africa and Colombia, with rates between 10% and 20%. During the study period from 2020 to 2021, Asia had the highest MIC90 value (4 mg/L) for ceftriaxone in S. pneumoniae isolates, and the geometric mean of MICs increased from 0.25 mg/L in 2016-2017 to 0.39 mg/L in 2020-2021. Both Asia (from 83.4% to 75.1%) and Latin America (from 94.2% to 86.3%) showed a decreasing trend in ceftriaxone susceptibility rates from 2016 to 2021. In North America, Europe and Oceania, the susceptibility rate was higher than 95%, and there was no obvious change in the rate during the 6 y. Further analysis of the data from Asia revealed that individuals younger than 6 y of age had a lower susceptibility rate to ceftriaxone (71.6% vs. 81.7%, P < 0.05) than patients ≥6 y. The higher non-susceptibility rates of ceftriaxone in S. pneumoniae in Asia may lead to therapeutic challenges in community-acquired pneumonia.

Complete genome analysis of Lactiplantibacillus plantarum VHProbi P06, a novel probiotic that resists Streptococcus pneumoniae in the upper respiratory tract

The purpose of this study was to screen lactic acid bacteria active against Streptococcus pneumoniae and to analyze the genetic basis of their probiotic functions from the genome. We isolated a novel Lactiplantibacillus plantarum VHProbi P06 from pickles, which showed strong antibacterial activity against S. pneumoniae, adhesion to 5-8F cells, and inhibition of S. pneumoniae colonization in the respiratory tract. Genome of VHProbi P06 was analyzed, we found one class II bacteriocin synthesis gene cluster. Genome of the strain contained 42 adhesion-related protein-coding genes, and implicated three exopolysaccharide biosynthesis gene clusters with low homologous to L. plantarum WCFS1. Moreover, VHProbi P06 possessed 3 intact phage regions and 117 Carbohydrate Active Enzyme genes. By comparing the genomes of five L. plantarum, 275 unique genes were found in VHProbi P06. Finally, the gene prediction was verified, the bacteriocin PlnJK produced by P06 was identified by LC-MS/MS, and the laminar exopolysaccharide with a weight-averaged molecular of 125.37 KDa was also found. This study provides a theoretical basis for the application of VHProbi P06 to the upper respiratory tract to resist pathogenic bacteria.

A Review of the Resistance Mechanisms for β-Lactams, Macrolides and Fluoroquinolones among Streptococcus pneumoniae

Streptococcus pneumoniae (S. pneumoniae) is a bacterial species often associated with the occurrence of community-acquired pneumonia (CAP). CAP refers to a specific kind of pneumonia that occurs in individuals who acquire the infection outside of a healthcare setting. It represents the leading cause of both death and morbidity on a global scale. Moreover, the declaration of S. pneumoniae as one of the 12 leading pathogens was made by the World Health Organization (WHO) in 2017. Antibiotics like β-lactams, macrolides, and fluoroquinolones are the primary classes of antimicrobial medicines used for the treatment of S. pneumoniae infections. Nevertheless, the efficacy of these antibiotics is diminishing as a result of the establishment of resistance in S. pneumoniae against these antimicrobial agents. In 2019, the WHO declared that antibiotic resistance was among the top 10 hazards to worldwide health. It is believed that penicillin-binding protein genetic alteration causes β-lactam antibiotic resistance. Ribosomal target site alterations and active efflux pumps cause macrolide resistance. Numerous factors, including the accumulation of mutations, enhanced efflux mechanisms, and plasmid gene acquisition, cause fluoroquinolone resistance. Furthermore, despite the advancements in pneumococcal vaccinations and artificial intelligence (AI), it is not feasible for individuals to rely on them indefinitely. The ongoing development of AI for combating antimicrobial resistance necessitates more research and development efforts. A few strategies can be performed to curb this resistance issue, including providing educational initiatives and guidelines, conducting surveillance, and establishing new antibiotics targeting another part of the bacteria. Hence, understanding the resistance mechanism of S. pneumoniae may aid researchers in developing a more efficacious antibiotic in future endeavors.

Antibiotic Resistance of Streptococcus pneumoniae in the Nasopharynx of Healthy Children Less than Five Years Old after the Generalization of Pneumococcal Vaccination in Marrakesh, Morocco

Streptococcus pneumoniae (S. pneumoniae) remains one of the most important pathogens causing childhood infections. The spread of antibiotic-resistant bacteria is a leading cause of treatment failure in children. The purpose of this investigation is to report the antibiotic and multidrug resistance (MDR) of S. pneumoniae strains isolated from healthy children throughout the years 2020–2022. Antimicrobial susceptibility testing of S. pneumoniae strains in selected antimicrobials was performed using disk diffusion and E-test methods on bloodMueller–Hinton agar. The antimicrobials tested included oxacillin, amoxicillin, ceftriaxone, norfloxacin, gentamicin, vancomycin, erythromycin, clindamycin, pristinamycin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. A total of 201 S. pneumoniae strains were isolated from the nasopharynx of healthy children in Marrakesh, Morocco. The highest rate of resistance of S. pneumoniae was found in penicillin (57.2%), followed by tetracycline (20.9%), and erythromycin (17.9%). The rates of resistance to clindamycin, trimethoprim-sulfamethoxazole, and chloramphenicol were 14.9%, 4%, and 1.5%, respectively. All isolates were susceptible to norfloxacin, gentamicin, vancomycin, and pristinamycin. Approximately 17% of all S. pneumoniae strains were resistant to at least three different antibiotic families. This study showed a low rate of antibiotics resistance among nasopharyngeal S. pneumoniae strains, and it is thus essential to monitor S. pneumoniae susceptibility in healthy children.

Feasibility, acceptability, and bacterial recovery for community-based sample collection to estimate antibiotic resistance in commensal gut and upper respiratory tract bacteria

Vietnam has high rates of antibiotic use and resistance. Measuring resistance in commensal bacteria could provide an objective indicator for evaluating the impact of interventions to reduce antibiotic use and resistance. This study aimed to evaluate the feasibility, acceptability, and bacterial recovery for different sampling strategies. We conducted a cross-sectional mixed methods study in a rural community in Ha Nam Province, northern Vietnam, and collected structured interviews, samples, and in-depth interviews from households. Out of 389 households invited, 324 participated (83%), representing 1502 individuals. Samples were collected from these individuals (1498 stool, 1002 self-administered nasal swabs, and 496 HW-administered nasopharyngeal swabs). Pneumococci were recovered from 11.1% (128/1149) of the total population and 26.2% (48/183) of those under 5-years. Recovery was higher for health-worker (HW)-administered swabs (13.7%, 48/350) than self-administered swabs (10.0%, 80/799) (OR 2.06, 95% CI 1.07-3.96). Cost per swab was cheaper for self-administered ($7.26) than HW-administered ($8.63) swabs, but the overall cost for 100 positive samples was higher ($7260 and $6300 respectively). Qualitative interviews revealed that HW-administered nasopharyngeal swabs took longer to collect, caused more discomfort, and were more difficult to take from children. Factors affecting participation included sense of contribution, perceived trade-offs between benefits and effort, and peer influence. Reluctance was related to stool sampling and negative perceptions of research. This study provides important evidence for planning community-based carriage studies, including cost, logistics, and acceptability. Self-administered swabs had lower recovery, and though cheaper and quicker, this would translate to higher costs for large population-based studies. Recovery might be improved by swab-type, transport medium, and better cold-chain to lab.

Lung penetration and pneumococcal target binding of antibiotics in lower respiratory tract infection

OBJECTIVES

To achieve the therapeutic effects, antibiotics must penetrate rapidly into infection sites and bind to targets. This study reviewed updated knowledge on the ability of antibiotics to penetrate into the lung, their physicochemical properties influencing the pulmonary penetration and their ability to bind to targets on pneumococci.

METHODS

A search strategy was developed using PubMED, Web of Science, and ChEMBL. Data on serum protein binding, drug concentration, target binding ability, drug transporters, lung penetration, physicochemical properties of antibiotics in low respiratory tract infection (LRTI) were collected.

RESULTS

It was seen that infection site-to-serum concentration ratios of most antibiotics are >1 at different time points except for ceftriaxone, clindamycin and vancomycin. Most agents have proper physicochemical properties that facilitate antibiotic penetration. In antimicrobial-resistant Streptococcus pneumoniae, the binding affinity of antibiotics to targets mostly decreases compared to that in susceptible strains. The data on binding affinity of linezolid, clindamycin and vancomycin were insufficient. The higher drug concentration at the infection sites compared to that in the blood can be associated with inflammation conditions. Little evidence showed the effect of drug transporters on the clinical efficacy of antibiotics against LRTI.

CONCLUSIONS

Data on antibiotic penetration into the lung in LRTI patients and binding affinity of antibiotics for pneumococcal targets are still limited. Further studies are required to clarify the associations of the lung penetration and target binding ability of antibitotics with therapeutic efficacy to help propose the right antibiotics for LRTI.

Country data on AMR in Vietnam in the context of community-acquired respiratory tract infections: links between antibiotic susceptibility, local and international antibiotic prescribing guidelines, access to medicines and clinical outcome

Background

Antimicrobial resistance (AMR) is one of the biggest threats to global public health. Selection of resistant bacteria is driven by inappropriate use of antibiotics, amongst other factors. COVID-19 may have exacerbated AMR due to unnecessary antibiotic prescribing. Country-level knowledge is needed to understand options for action.

Objectives

To review the current situation with respect to AMR in Vietnam and initiatives addressing it. Identifying areas where more information is required will provide a call to action to minimize any further rises in AMR within Vietnam and improve patient outcomes.

Methods

National initiatives to address AMR in Vietnam, antibiotic use and prescribing, and availability of susceptibility data, in particular for the key community-acquired respiratory tract infection (CA-RTI) pathogens Streptococcus pneumoniae and Haemophilus influenzae, were identified. National and international antibiotic prescribing guidelines for CA-RTIs (community-acquired pneumonia, acute otitis media and acute bacterial rhinosinusitis) commonly used locally were also reviewed, plus local antibiotic availability. Insights from clinicians in Vietnam were sought to contextualize this information.

Conclusions

In Vietnam there have been some initiatives addressing AMR; Vietnam was the first country in the Western Pacific Region to develop a national action plan to combat AMR, which according to the WHO is being implemented. Vietnam also has one of the highest rates of AMR in Asia due, in part, to the overuse of antimicrobial drugs, both in the animal health sector and in humans in both hospitals and the community. In addition, despite a 2005 law requiring antibiotic prescription, there is unrestricted access to over-the-counter antibiotics. Several global surveillance studies provide antibiotic susceptibility data for CA-RTI pathogens in Vietnam including Survey of Antibiotic Resistance (SOAR) and SENTRY (small isolate numbers only). For management of the common CA-RTIs in Vietnam there are several country-specific local antibiotic prescribing guidelines and in addition, there is a range of international guidelines referred to, but these may have been created based on pathogen resistance patterns that might be very different to those in Vietnam. Expert clinician opinion confirms the high resistance rates among common respiratory pathogens. A more standardized inclusive approach in developing local guidelines, using up-to-date surveillance data of isolates from community-acquired infections in Vietnam, could make management guideline use more locally relevant for clinicians. This would pave the way for a higher level of appropriate antibiotic prescribing and improved adherence. This would, in turn, potentially limit AMR development and improve clinical outcomes for patients.

Cephalosporins-induced intestinal dysbiosis exacerbated pulmonary endothelial barrier disruption in streptococcus pneumoniae-infected mice

Antibiotic abuse is growing more severe in clinic, and even short-term antibiotic treatment can cause long-term gut dysbiosis, which may promote the development and aggravation of diseases. Cephalosporins as the broad-spectrum antibiotics are widely used for prevention and treatment of community-acquired respiratory tract infection in children. However, their potential consequences in health and disease have not been fully elaborated. In this study, the effects of cefaclor, cefdinir and cefixime on intestinal microbiota and lung injury were investigated in Streptococcus pneumoniae (Spn)-infected mice. The results showed that the proportion of coccus and bacillus in intestinal microbiota were changed after oral administration with cefaclor, cefdinir and cefixime twice for 10 days, respectively. Compared with the Spn-infected group, the proportion of Bifidobacterium and Lactobacillus in intestine were significantly reduced, while Enterococcus and Candida was increased after cephalosporin treatment. Furthermore, 3 cephalosporins could obviously increase the number of total cells, neutrophils and lymphocytes in BALF as well as the serum levels of endotoxin, IL-2, IL-1β, IL-6 and TNF-α. Mechanically, cephalosporins accelerated Spn-induced pulmonary barrier dysfunction via mediating the mRNA expressions of endothelial barrier-related proteins (Claudin 5, Occludin, and ZO-1) and inflammation-related proteins (TLR4, p38 and NF-κB). However, all of those consequences could be partly reversed by Bifidobacterium bifidum treatment, which was closely related to the elevated acetate production, indicating the protective effects of probiotic against antibiotic-induced intestinal dysbiosis. Therefore, the present study demonstrated that oral administration with cephalosporins not only disrupted intestinal microecological homeostasis, but also increased the risk of Spn infection, resulting in severer respiratory inflammation and higher bacterial loads in mice.

Effectiveness of an enhanced antibiotic stewardship programme amongst paediatric patients in a tertiary hospital in Vietnam

BACKGROUND

In 2016, the Vietnamese Ministry of Health promoted development of antimicrobial stewardship for hospitals.

AIM

To evaluate the effectiveness and safety of the enhanced antibiotic stewardship programme (ASP) compared to the original ASP amongst paediatric patients at a tertiary hospital for infectious diseases in Vietnam.

METHODS

We conducted an interrupted time series analysis to examine antibiotic use in paediatric patients aged 0 to 17 years admitted to the Hospital for Tropical Diseases in Ho Chi Minh City from April 2016 to March 2020. Outcomes measured were defined daily doses (DDDs) per 1000 patient-days; antibiotic days of therapy (DOT) per 1000 patient-days; percentage of antibiotic use by the WHO Access, Watch, and Reserve (AWaRe) system; Access-to-Watch ratio; and worse clinical outcomes at discharge.

FINDINGS

Of 60,172 admissions during the study period, 28,019 received at least one antibiotic (46.6%) during hospital stay. The Watch antibiotics were the most commonly prescribed (78.1% of total antibiotic courses). The enhanced ASP did not improve antibiotic prescribing by DDDs per 1000 patient-days (RR: 1.05, 95%CI: 0.94-1.17) and DOT per 1000 patient-days (RR: 1.11, 95%CI: 0.99-1.25) compared to the original ASP. However, the percentage of Access antibiotics prescribed, and the Access-to-Watch ratio increased after the enhanced ASP (RR: 1.73, 95%CI: 1.38-2.17). There was no significant difference in worse clinical outcomes at discharge between the original and enhanced ASP (RR: 1.25, 95%CI: 0.78-2.00).

CONCLUSION

The enhanced ASP had modest impact on antibiotic consumption in paediatric population despite the improvement of Access antibiotic use and the Access-to-Watch ratio.

Predicting Oral Beta-lactam susceptibilities against Streptococcus pneumoniae

BACKGROUND

Oral beta-lactam antimicrobials are not routinely tested against Streptococcus pneumoniae due to presumed susceptibility based upon penicillin minimum inhibitory concentration (MIC) testing. Currently, Clinical and Laboratory Standards Institute provides comments to use penicillin MIC ≤0.06 to predict oral cephalosporin susceptibility. However, no guidance is provided when cefotaxime MIC is known, leading to uncertainty with interpretation. The purpose of this study was to evaluate cefotaxime and penicillin MICs and their respective correlation to oral beta-lactam categorical susceptibility patterns.

METHODS

249 S. pneumoniae isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-ToF) and then tested by broth microdilution method to penicillin, cefotaxime, amoxicillin, cefdinir, cefpodoxime, and cefuroxime.

RESULTS

Using Clinical and Laboratory Standards Institute (CLSI) non-meningitis breakpoints for cefotaxime, 240/249 isolates were classified as susceptible. Of the cefotaxime susceptible isolates, 23% of the isolates are misrepresented as cefdinir susceptible. Amoxicillin correlated well with penicillin MIC breakpoints with only 1 discordant isolate out of 249.

CONCLUSION

The correlation between amoxicillin and penicillin creates a very reliable predictor to determine categorical susceptibility. However oral cephalosporins were not well predicted by either penicillin or cefotaxime leading to the possible risk of treatment failures. Caution should be used when transitioning to oral cephalosporins in cefotaxime susceptible isolates, especially with higher cefotaxime MICs.