Antimicrobial resistance in bacterial pathogens among hospitalized children with community acquired lower respiratory tract infections in Dongguan, China (2011-2016)

Antimicrobial susceptibility and serotype distribution of Streptococcus pneumoniae isolates among children in Suzhou, China

Background

Streptococcus pneumoniae (SP) is responsible for pneumococcal diseases with severe morbidity and mortality. High rates of drug resistance constitute serious public health concerns. Vaccination has proven to be an effective means of reducing disease burden. Epidemiological information of antibiotic susceptibilities and serotype distribution will be of great help to the management of pneumococcal infections. This study reported the serotype distribution and antibiotic resistance pattern of SP in hospitalized children in Suzhou during the years 2017-2018. The aim is to reduce pneumococcal resistance and guide vaccination.

Methods

The clinical data of hospitalized children with SP were collected and analyzed. A total of 2,446 strains of SP were isolated from these patients. Serotypes were determined using the Quellung reaction. Antibiotic resistance was tested using the E-test diffusion method.

Results

The non-susceptible rates of the isolates to penicillin, amoxicillin, and cefotaxime were 9.5%, 27.7%, and 27.2%, respectively. And 97.6% of SP isolates showed multidrug-resistant (MDR). The most common resistance pattern of non-invasive isolates was macrolides + sulfamethoxazole + clindamycin + tetracycline. The major serotypes of this resistance pattern were 6A, 23F, 6B, 19F, 15B. The most extensive resistance pattern of invasive isolates was macrolides + β-lactams + sulfamethoxazole + clindamycin + tetracycline. The most common serotypes of the pattern were 19F, 19A, 6B, 23F, 6A. The most common serotypes were 19F (28.6%), 6B (11.9), 23F (11.2%), 6A (10.6%), and 19A (9.1%). In the isolates with MDR, the first five most common serotypes were 19F, non-vaccine serotype (NVT), 6B, 6A and 23F. Strains belonging to different serotypes exhibited distinct antimicrobial resistance patterns and were found to be associated with different diseases. The coverage rates of pneumococcal conjugate vaccine (PCV)7 and PCV13 in all isolates reached 60.4% (310/513) and 80.9% (415/513), respectively.

Conclusions

The main serotypes of SP in Suzhou were 19F, 6B, 23F, 6A, and 19A. The use of PCV13 is beneficial to children in Suzhou.

Severe problem of macrolides resistance to common pathogens in China

With the widespread use of macrolide antibiotics in China, common pathogens causing children's infections, such as Streptococcus pneumoniae, Streptococcus (including Group A streptococcus, Group B streptococcus), Staphylococcus aureus, Bordetella pertussis, and Mycoplasma pneumoniae, have shown varying degrees of drug resistance. In order to provide such problem and related evidence for rational use of antibiotics in clinic, we reviewed the drug resistance of common bacteria to macrolides in children recent 20 years.

Prevalence and molecular characteristics of community-associated methicillin-resistant Staphylococcus aureus in the respiratory tracts of Chinese adults with community-acquired pneumonia

BACKGROUND

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is an important pathogen causing healthcare-associated infections. In recent years, an increasing number of CA-MRSA clones have emerged and rapidly spread in the community and hospital settings in China.

OBJECTIVES

To investigate the molecular epidemiology and resistance of CA-MRSA in the respiratory tracts of Chinese adults with community-acquired pneumonia (CAP).

METHODS

A total of 243 sputum samples were collected from adult patients with CAP at the Nantong Hospital in China between 2018 and 2021. S. aureus was identified using PCR, and its susceptibility to 14 antimicrobials was tested using the broth dilution method. Genomic characterization of respiratory CA-MRSA and our previously collected intestinal CA-MRSA isolates was performed using whole-genome sequencing, and the evolutionary relationships of these isolates were assessed using phylogenetic analysis.

RESULTS

The CA-MRSA colonization rate among adults with CAP in China was 7.8 % (19/243). Antimicrobial resistance analysis revealed that the proportion of multidrug-resistant respiratory CA-MRSA isolates (100 %) was higher than that of intestinal CA-MRSA isolates (6.3 %). Among the 35 CA-MRSA isolates, 10 MLST types were identified and clustered into five clone complexes (CCs). CC5 (48.6 %) and CC88 (20 %) were predominant CA-MRSA clones. Notably, the CC5 clone ST764/ST6292-MRSA-II-t002 was identified as the major lineage causing respiratory tract infections in Chinese adults with CAP.

CONCLUSIONS

The prevalence of CA-MRSA among Chinese adults with CAP is high and often involves ST764/ST6292-MRSA-II-t002 as the causal pathogen.

High incidence of the virus among respiratory pathogens in children with lower respiratory tract infection in northwestern China

Lower respiratory tract infection (LRTI) is one of the major reasons for childhood mortality that threaten the health of the public. We aimed to investigate the epidemiological pathogens and their infection analysis among children with LRTI. Sputum specimens were collected for polymerase chain reaction detection and microbiological tests to identify the viral infection and bacterial infection. The serological specimens were separated from venous blood using for Mycoplasma pneumoniae and Chlamydia pneumoniae detection. The virus was confirmed in 86.2% of the children. Human rhinovirus (38.3%), respiratory syncytial virus (32.1%), and parainfluenza virus type 3 (27.2%) were the most frequently identified pathogens. Patients with viral and bacterial coinfection showed younger age (p = 0.032), a higher proportion of wheezing rales (p = 0.032), three depressions sign (p = 0.028), and tachypnea (p = 0.038), and more likely associated with severe pneumonia (p = 0.035). Additionally, older children were more susceptible to viral-atypical bacterial coinfection (p = 0.032). Vomiting (p = 0.011) and fever (p = 0.003) were more likely to occur in children with viral-atypical bacterial coinfection. Attention should be paid to the virus infection of LRTI, as viral-bacterial coinfection and viral-atypical bacterial co-infection may have a detrimental impact on the gravity of LTRI.

Clonal Diversity and Molecular Characteristics of Methicillin-Susceptible and -Resistant Staphylococcus aureus from Pediatric Patients in Myanmar

The spread of multidrug-resistant and virulent Staphylococcus aureus among children is a public health concern, but the actual conditions in Myanmar have not been characterized. In this study, a total of 244 clinical isolates of S. aureus collected from pediatric patients in Yangon Children's Hospital during a 1-year period were analyzed for their drug resistance and genetic features. Methicillin-resistant S. aureus (MRSA) accounted for 19.7% of isolates associated with staphylococcal cassette chromosome mec (SCCmec) type III, IV, or V. Panton-Valentine leukocidin (PVL) genes were detected in 61.5% of all isolates, with a significantly higher prevalence in methicillin-susceptible S. aureus (MSSA; 67.9%) than in MRSA (35.4%) isolates. Sequence type (ST) 239/SCCmec-III was the most common MRSA clone lacking PVL genes, while PVL-positive MRSA belonged to mostly ST361/SCCmec-V and ST772/SCCmec-V. Among MSSA isolates, ST121, ST2990, ST88, and ST1930 were dominant, harboring mostly PVL genes. ST239 MRSA isolates exhibited the highest resistance rates to antimicrobials, and quinolone resistance was found in the dominant MRSA clones (ST239, ST361, and ST772) and some MSSA lineages. The present study revealed the prevalence and clonal diversity of MRSA/MSSA in children in Myanmar in relation to drug resistance and virulence determinants.

Effectiveness of Pharmacist-Led Brief Educational Intervention for Adherence to the Antibiotics for Lower Respiratory Tract Infections (EATSA) in Post-Conflict Rural Areas of Pakistan: Study Protocol for a Randomized Controlled Trial

Globally, lower respiratory infections (LRTIs) are one of the most common infectious diseases whichaffect majority of the population and as a result of inappropriate antibiotics practices lead to antibiotic resistance (AR). An individual randomized control trial will be conducted in the post-conflict areas of Swat, Pakistan, through a random sampling method. Patients aged > 18 years will be recruited from five community pharmacies and assigned to equally sized groups to receive either pharmacist-led education interventions or usual care with no intervention. A total of 400 (control = 200, study = 200) patients will be included, with prescriptions comprised of antibiotics for LRTIs. The outcomes measured in both groups will be a combination of treatment cure rate and adherence, which will be assessed using the Morisky Medication Adherence Scale and pill count. The trial comprises pharmacist-led educational interventions to improve treatment outcomes for patients with LRTIs. This study might establish the groundwork for pharmaceutical care of LRTIs patients with antibacterial therapy and the future delivery of a care strategy for the improvement of LRTIs treatment outcomes in post-conflict, remote areas of the third world and LMICs.

Going shopping or consulting in medical visits: Caregivers' roles in pediatric antibiotic prescribing in China

Antimicrobial Resistance (AMR) is one of the gravest global public health crises today. Over-prescription in clinical settings is a primary driver. Despite its magnitude and scale, the problem of antibiotic over-prescription in China has not been understood adequately nor addressed effectively. Based on a corpus of 183 video-recorded medical conversations in the Chinese pediatric setting, we show that patient caregivers frequently challenge the physician's medical authority by resisting treatment recommendations, displaying a high level of entitlement to influence the treatment decision. As a result, even when the physicians do not recommend antibiotics based on their professional judgment, they prescribe in response to caregiver pressure. We argue that the relatively low level of medical authority is a significant contributor to the problem. Under this consumerist model of doctor-patient relationship, antibiotics are oriented to by the caregivers as a negotiable commodity and physicians are unable to fulfill their role as gatekeepers. Educational campaigns are needed to promote rational use of antibiotics among patients and caregivers, and serious efforts are called for to protect physicians' professional authority in China.

One cross-sectional investigation revealed that non-vaccine serotypes of Streptococcus pneumoniae could be identified more frequently in elderly Chinese people

OBJECTIVE

To analyze the serotype distribution and drug resistance of Streptococcus pneumoniae isolated from hospitalized patients of all ages in Zhongjiang county, Sichuan province, where the young children have just begun to vaccinate the PCV13 in private sector.

METHODS

Serotypes were determined for 387 isolates of S. pneumoniae by Quellung reaction. Antibiotic susceptibility was tested with the E-test or disc diffusion method.

RESULTS

The most common serotypes were type 19F and confirmed for 88 isolates (22.7%), followed by 19A (15.0%), 6B (7.8%), 16F (7.8%), 23F (7.0%) and 15A (4.4%). The coverage rates of PCV13 and PPSV23 were 63.3% and 65.1%. With the increase of age, the proportion of PCV13 types decreased significantly, from 71.3% (<2 years old) to 41.9% (≥60 years old). The intermediate rate and resistance rate of the isolates to oral penicillin were 48.6% and 45.2%, respectively. The resistance rate of erythromycin was high (94.4%). The PCV13 isolates was more resistant to penicillin than the non-PCV13 ones.

CONCLUSION

The PCV13 coverage rate in pediatric isolates was higher than those in adult isolates. The adults, especially the elderly, may be the reservoir of non-PCV13 types. It is necessary to investigate the serotype distribution of S. pneumoniae based on all age population to assess potential epidemics of non-vaccine serotype associated with PCVs administration.

Detection of Eight Respiratory Bacterial Pathogens Based on Multiplex Real-Time PCR with Fluorescence Melting Curve Analysis

Background and Objective. Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Pseudomonas aeruginosa, and Mycobacterium tuberculosis are primary respiratory bacterial pathogens contributing to morbidity and mortality in developing countries. This study evaluated the diagnostic performance of multiplex real-time PCR with fluorescence melting curve analysis (MCA) assay, which was used to detect eight respiratory bacterial pathogens simultaneously.

Methods

A total of 157 sputum specimens were examined by multiplex real-time with fluorescence MCA, and the results were compared with the conventional culture method.

Results

Multiplex real-time PCR with fluorescence MCA specifically detected and differentiated eight respiratory bacterial pathogens by different melting curve peaks for each amplification product within 2 hours and exhibited high repeatability. The limit of detection ranged from 64 to 10² CFU/mL in the multiplex PCR system. Multiplex real-time PCR with fluorescence MCA showed a sensitivity greater than 80% and a 100% specificity for each pathogen. The kappa correlation of eight bacteria ranged from 0.89 to 1.00, and the coefficient of variation ranged from 0.05% to 0.80%.

Conclusions

Multiplex real-time PCR with fluorescence MCA assay is a sensitive, specific, high-throughput, and cost-effective method to detect multiple bacterial pathogens simultaneously.

Immunoglobulin M profile of viral and atypical pathogens among children with community acquired lower respiratory tract infections in Luzhou, China

Background

Community-acquired lower respiratory tract infections (CA-LRTIs) are the primary cause of hospitalization among children globally. A better understanding of the role of atypical pathogen infections in native conditions is essential to improve clinical management and preventive measures. The main objective of this study was to detect the presence of 7 respiratory viruses and 2 atypical pathogens among hospitalized infants and children with community-acquired lower respiratory tract infections in Luzhou via an IgM test.

Methods

Overall, 6623 cases of local hospitalized children with 9 pathogen-IgM results from 1st July 2013 to 31st Dec 2016 were included; multidimensional analysis was performed.

Results

1) Out of 19,467 hospitalized children with lower respiratory tract infections, 6623 samples were collected, for a submission ratio of 33.96% (6623 /19467). Of the total 6623 serum samples tested, 5784 IgM stains were positive, for a ratio of 87.33% (5784 /6623). Mycoplasma pneumoniae (MP) was the dominant pathogen (2548 /6623, 38.47%), with influenza B (INFB) (1606 /6623, 24.25%), Legionella pneumophila serogroup 1 (LP1) (485 /6623, 7.32%) and parainfluenza 1, 2 and 3(PIVs) (416 /6623, 6.28%) ranking second, third and fourth, respectively.

2) The distribution of various pathogen-IgM by age group was significantly different (χ² = 455.039, P < 0.05).

3) Some pathogens were found to be associated with a certain age of children and seasons statistically.

Conclusions

The dominant positive IgM in the area was MP, followed by INFB, either of which prefers to infect children between 2 years and 5 years in autumn. The presence of atypical pathogens should not be underestimated clinically as they were common infections in the respiratory tract of children in the hospital.

Evaluating the antimicrobial resistance patterns among major bacterial pathogens isolated from clinical specimens taken from patients in Mofid Children's Hospital, Tehran, Iran: 2013-2018

BACKGROUND

This study evaluates the epidemiology and antimicrobial resistance profile of Gram-negative bacteria (GNB) and Gram-positive bacteria (GPB) isolated from clinical specimens in children admitted to Mofid Children's Hospital.

METHODS

This was a retrospective study of the patients' clinical specimens collected from January 2013 until the end of December 2018. All specimens were evaluated to determine the presence of infection-causing agents using a BACTEC 9120 blood culture. Isolation and identification of bacterial strains were performed using conventional biochemical tests. Antibiotic resistance was determined using Kirby-Bauer disk diffusion and broth microdilution methods. Results were interpreted according to CLSI and EUCAST.

RESULTS

A total of 1130 different pathogenic bacteria were detected from 14,690 different clinical specimens and the overall detection rate was 7.7% (1130/14,690). Among bacterial pathogen isolated from clinical specimens, 55% (n=622) were GNB and 45% (n=508) were GPB. The predominant GNB isolates were Pseudomonas aeruginosa, Klebsiella spp., Acinetobacter baumannii, Escherichia coli, Enterobacter spp., Citrobacter spp., respectively. Among GPB, CoNS was the most frequent and Enterococcus spp. was found to have low levels of resistance to linezolid. In GNB, most A. baumannii and P. aeruginosa were ceftriaxone resistant. P. aeruginosa was found to have low levels of resistance to levofloxacin and ciprofloxacin.

CONCLUSIONS

Our findings revealed that the resistance rate among GNB and GPB associated with different infections in children is very high. These results suggest a constant screening and follow-up programs for the detection of antibiotic resistance, and it also suggests to develop antimicrobial stewardship programs in Tehran, Iran.

Available evidence of antibiotic resistance from extended-spectrum β-lactamase-producing Enterobacteriaceae in paediatric patients in 20 countries: a systematic review and meta-analysis

OBJECTIVE

To make a systematic review of risk factors, outcomes and prevalence of extended-spectrum β-lactamase-associated infection in children and young adults in South-East Asia and the Western Pacific.

METHODS

Up to June 2018 we searched online databases for published studies of infection with extended-spectrum β-lactamase-producing Enterobacteriaceae in individuals aged 0-21 years. We included case-control, cohort, cross-sectional and observational studies reporting patients positive and negative for these organisms. For the meta-analysis we used random-effects modelling of risk factors and outcomes for infection, and meta-regression for analysis of subgroups. We mapped the prevalence of these infections in 20 countries and areas using available surveillance data.

FINDINGS

Of 6665 articles scanned, we included 40 studies from 11 countries and areas in the meta-analysis. The pooled studies included 2411 samples testing positive and 2874 negative. A higher risk of infection with extended-spectrum β-lactamase-producing bacteria was associated with previous hospital care, notably intensive care unit stays (pooled odds ratio, OR: 6.5; 95% confidence interval, CI: 3.04 to 13.73); antibiotic exposure (OR: 4.8; 95% CI: 2.25 to 10.27); and certain co-existing conditions. Empirical antibiotic therapy was protective against infection (OR: 0.29; 95% CI: 0.11 to 0.79). Infected patients had longer hospital stays (26 days; 95% CI: 12.81 to 38.89) and higher risk of death (OR: 3.2; 95% CI: 1.82 to 5.80). The population prevalence of infection was high in these regions and surveillance data for children were scarce.

CONCLUSION

Antibiotic stewardship policies to prevent infection and encourage appropriate treatment are needed in South-East Asia and the Western Pacific.

Antimicrobial resistance, virulence genes profiling and molecular relatedness of methicillin-resistant Staphylococcus aureus strains isolated from hospitalized patients in Guangdong Province, China

PURPOSE

The main objective of this study was to decipher the prevalence, antimicrobial resistance, major virulence genes and the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolated from different clinical sources in southern China.

MATERIALS AND METHODS

The present study was performed on 187 non-duplicate S. aureus clinical isolates collected from three tertiary hospitals in Guangdong Province, China, 2010-2016. Antimicrobial susceptibility testing was performed by the disk diffusion method and by measuring the minimum inhibitory concentration. Screening for resistance and virulence genes was performed. Clonal relatedness was determined using various molecular typing methods such as multilocus sequence typing, spa and staphylococcal chromosomal cassette mec (SCCmec) typing. Whole genome sequencing was performed for three selected isolates.

RESULTS

Out of 187 isolates, 103 (55%) were identified as MRSA. The highest prevalence rate was found among the skin and soft tissue infection (SSTI) samples (58/103), followed by sputum samples (25/103), blood stream infection samples (15/103) and others (5/103). Antimicrobial susceptibility results revealed high resistance rates for erythromycin (64.1%), clindamycin (48.5%), gentamicin (36.9%) and ciprofloxacin (33.98%). All isolates were susceptible to vancomycin. Resistance genes and mutation detected were as follows: aac(6')-aph(2") (24.3%), dfrG (10.7%), rpoB (21.4%), cfr (0%), fexA (1.94%), gyrA (35.92%), gyrB (0.97%), grlA (20.4%), grlB (10.68%), ermA (21.4%), ermB (18.44%), ermC (21.4%) and lnuA (18.44%). Profiling of virulence genes revealed the following: sea (11.7%), seb (21.4%), sec (0.97%), sed (0.97%), hla (86.41%), hlb (17.48%), hlg (10.68%), hld (53.4%), Tsst-1 (3.9%) and pvl (27.2%). Clonal relatedness showed that ST239-SCCmecA III-t37 clone was the most prevalent clone.

CONCLUSION

Our study elucidated the prevalence, antibiotic resistance, pathogenicity and molecular characteristics of MRSA isolated from various clinical sources in Guangdong, China. We found that the infectious rate of MRSA was higher among SSTI than other sources. The most predominant genotype was ST239-SCCmecA III-t37 clone, indicating that ST239-t30 clone which was previously predominant had been replaced by a new clone.

Molecular and Conventional Analysis of Acute Diarrheal Isolates Identifies Epidemiological Trends, Antibiotic Resistance and Virulence Profiles of Common Enteropathogens in Shanghai

Objective: To investigate prevalence of acute diarrhea in Shanghai and analyze virulence associated-genes and antibiotic resistance of major enteropathogens using combination of conventional and molecular epidemiology methods. Method: The 412 stool specimens were obtained by systematic sampling from diarrhea patients throughout entire year 2016. Bacterial and viral pathogens were identified and bacterial isolates were cultured and screened for antibiotic resistance profiles. Two most prevalent bacteria, Vibrio parahaemolyticus and Salmonella were further typed by multi-locus sequence typing (MLST) and analyzed for presence of virulence-associated genes. The association between virulence genes, resistance phenotypes and genetic diversities was analyzed. Results: Among stool specimens testing positive for pathogens (23.1%), 59 bacterial and 36 viral pathogens were identified. V. parahaemolyticus (27/412, 6.6%), Salmonella (23/412, 5.6%) and norovirus GII (21/412, 5.1%) were three most-commonly found. Most bacterial isolates exhibited high levels of antibiotic resistance with high percentage of MDR. The drug resistance rates of V. parahaemolyticus and Salmonella isolates to cephalosporins were high, such as 100.0 and 34.8% to CFX, 55.6 and 43.4% to CTX, 92.6 and 95.7% to CXM, respectively. The most common resistance combination of V. parahaemolyticus and Salmonella was cephalosporins and quinolone. The dominant sequence types (STs) of V. parahaemolyticus and Salmonella were ST3 (70.4%) and ST11 (43.5%), respectively. The detection rates of virulence genes in V. parahaemolyticus were tlh (100%) and tdh (92.6%), without trh and ureR. Most of the Salmonella isolates were positive for the Salmonella pathogenicity islands (SPIs) genes (87-100%), and some for Salmonella plasmid virulence (SPV) genes (34.8% for spvA and spvB, 43.5% for spvC). In addition, just like the drug resistance, virulence genes exhibited wide-spread distribution among the different STs albeit with some detectable frequency linkage among Salmonella STs. Conclusion: Bacterial infections are still the major cause of severe diarrheas in Shanghai. The most common bacteria V. parahaemolyticus and Salmonella show molecular characteristics consistent with preselection of highly virulent types with exceedingly high level of antibiotic resistance.