Serotype Distribution, Antimicrobial Susceptibility, Multilocus Sequencing Type and Virulence of Invasive Streptococcus pneumoniae in China: A Six-Year Multicenter Study

Background:Streptococcus pneumoniae is an important human pathogen that can cause severe invasive pneumococcal diseases (IPDs). The aim of this multicenter study was to investigate the serotype and sequence type (ST) distribution, antimicrobial susceptibility, and virulence of S. pneumoniae strains causing IPD in China.Methods: A total of 300 invasive S. pneumoniae isolates were included in this study. The serotype, ST, and antimicrobial susceptibility of the strains, were determined by the Quellung reaction, multi-locus sequence typing (MLST) and broth microdilution method, respectively. The virulence level of the strains in the most prevalent serotypes was evaluated by a mouse sepsis model, and the expression level of well-known virulence genes was measured by RT-PCR.Results: The most common serotypes in this study were 23F, 19A, 19F, 3, and 14. The serotype coverages of PCV7, PCV10, PCV13, and PPV23 vaccines on the strain collection were 42.3, 45.3, 73.3 and 79.3%, respectively. The most common STs were ST320, ST81, ST271, ST876, and ST3173. All strains were susceptible to ertapenem, levofloxacin, moxifloxacin, linezolid, and vancomycin, but a very high proportion (>95%) was resistant to macrolides and clindamycin. Based on the oral, meningitis and non-meningitis breakpoints, penicillin non-susceptible Streptococcus pneumoniae (PNSP) accounted for 67.7, 67.7 and 4.3% of the isolates, respectively. Serotype 3 strains were characterized by high virulence levels and low antimicrobial-resistance rates, while strains of serotypes 23F, 19F, 19A, and 14, exhibited low virulence and high resistance rates to antibiotics. Capsular polysaccharide and non-capsular virulence factors were collectively responsible for the virulence diversity of S. pneumoniae strains.Conclusion: Our study provides a comprehensive insight into the epidemiology and virulence diversity of S. pneumoniae strains causing IPD in China.

Antimicrobial Resistance and Molecular Epidemiology of Escherichia coli From Bloodstream Infection in Shanghai, China, 2016–2019

Background: Bloodstream infections are recognized as important nosocomial infections. Escherichia coli (E. coli) is the most prevalent Gram-negative bacillary pathogen causing bloodstream infections (BSIs). This retrospective study investigated drug susceptibility and molecular epidemiology of E. coli isolated from patients with BSI in Shanghai, China.Methods: We collected E. coli isolated from the blood cultures of patients with BSI between January 2016 and December 2019. We randomly selected 20 strains each year to investigate antimicrobial resistance, resistance genes, and molecular epidemiological characteristics. Antimicrobial susceptibility testing was performed by the disk diffusion method. PCR was performed to detect extended-spectrum β-lactamases (ESBLs), carbapenemase genes, and housekeeping genes, and phyloviz was applied to analyze multilocus sequence typing (MLST).Results: Penicillins, first- and second-generation cephalosporins and fluoroquinolones have high resistance rates (>60%). Among the 80 randomly selected strains, 47 (58.8%) produced ESBLs, and one produced carbapenemase. Sequencing of resistance genes identified blaCTX−M−14 (34%, 16/47), blaCTX−M−15 (23.4%, 11/47) and blaCTX−M−27 (14.8%, 7/47) as the most prevalent genotypes of ESBLs. ST131 (14/80) was the most prevalent sequence type (ST), followed by ST1193 (10/80), ST648 (7/80).Conclusions: Our findings suggest that amikacin, carbapenems, and piperacillin-tazobactam have relatively low resistance rates and may be the preferred antibiotic regimens for empiric therapy. ST131 and blaCTX−M−14 are still the main prevalent in Shanghai with a rapid increase in the occurrence of ST1193 is rapidly increasing and more diverse blaCTX genes.

Increase in Penicillin and multidrug resistance in Streptococcus pneumoniae (1993-2016): report from a tertiary care hospital laboratory, Pakistan

Background: Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. With the emergence of penicillin-resistant S. pneumoniae (PRSP), treatment has become challenging. The Clinical and Laboratory Standards Institute (CLSI) in 2008 revised its guidelines for S. pneumoniae and recommended separate penicillin breakpoints for meningeal and non-meningeal strains. Similar to penicillin’s, resistance to other classes of antibiotics has emerged globally. Objective: The objective of this study is to determine the trend of resistance to antimicrobials in S. pneumoniae infections and the impact of new CLSI guidelines on penicillin susceptibility among meningeal isolates. Methodology: Twenty-four years (1993-2016) data from S. pneumoniae isolates and their antimicrobial susceptibility was retrieved from the computerized database. Data was divided into two groups for analysis, pre-2008 and post 2008. Results: Penicillin resistance remained unchanged in non-meningeal isolates during both study periods. A significant rise in penicillin resistance in meningeal isolates was observed in the second period 2008-2016 (2.9% vs 36.2%). High resistance rates were observed for co-trimoxazole, tetracycline and erythromycin. Increased trend of multi-drug resistant (MDR) strains were also noted, from 11% in 1999 to 36% in 2016. Conclusion: The emergence of MDR strains is evident from our dataset. It seems like the rise in PRSP in meningeal isolates is due to revised CLSI guidelines. Overall low resistance to penicillin in non-meningeal isolates and no resistance to ceftriaxone is encouraging and will assist in drafting local guidelines. Cautious use of antimicrobials are essential to reduce further emergence of antimicrobial resistance in indigenous isolates.

Revendo o tratamento para pneumonia causada por Staphylococcus aureus resistente à meticilina

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) can cause several infections, both dermatological and invasive infections, such as pneumonia, empyema and sepsis. Due to its importance and pathogenicity, it is considered a worldwide public health problem, which implies the need to search for more efficient therapeutic regimens. Specifically for the treatment of MRSA pneumonia, vancomycin and linezolid are the main drugs used. Objective: The main objective of this study was to compare the two drugs in terms of their effectiveness in the treatment of MRSA pneumonia, through a review of the most recent aspects of the literature. Methodology: Through a narrative review, the pros and cons of each therapeutic intervention were investigated, as well as the individual pharmacological aspects and the pathophysiology of the bacterial infection in question. Conclusion: Finally, it was concluded that linezolid is superior to vancomycin, with better rates of reduced mortality and length of hospital stay, along with a lower risk of complications and adverse events, in addition to greater therapeutic flexibility, better cost-effectiveness and lower resistance rates.

Antibiotic resistance rate of the Methicillin Resistant Staphylococcus aureus isolated from a university affiliated hospital in North Cyprus

Background: Over the past 20 years, studies have indicated that the increasing spread of methicillinresistant Staphylococcus aureus (MRSA) demonstrates the need for adequate information about their epidemiology. This study was conducted in order to investigate the resistance rate of MRSA which were isolated from the Near East University (NEU) Hospital, North Cyprus. Methods: MRSA was isolated and identified by using selective media and the Phoenix BD 100 system (software version 6.01A) was used for antimicrobial susceptibility testing and identification. The antimicrobial susceptibility results were determined according to the Clinical and Laboratory Standarts Institute (CLSI) and the resistance rates of MRSA isolates to antibiotics were examined retrospectively. Results: The highest number of samples were from the departments of chest disease (24%) followed by dermatology (21.3%) and cardiology (18.7%). Out of 75 MRSA strains,; 29.7% from blood, 25.3% from wound, 14.7% from nasal swabs, 10.7% from aspiration fluids, 9.3% from sputum, 6.7% were from urine, 4.0% from IV catheters culture samples. All strains of MRSA were 94.7% sensitive to vancomycin and teicoplanin. Conclusions: The obtained results revealed that preventative measures should be implemented in order to minimize the bacterial resistance to antibiotics. Bangladesh Journal of Medical Science Vol. 21(1) 2022 Page : 101-104

Risk Assessment of Future Antibiotic Resistance—Eliciting and Modelling Probabilistic Dependencies Between Multivariate Uncertainties of Bug-Drug Combinations

The increasing impact of antibacterial resistance concerns various stakeholders, including clinicians, researchers and decision-makers in the pharmaceutical industry, and healthcare policy-makers. In particular, possible multidrug resistance of bacteria poses complex challenges for healthcare risk assessments and for pharmaceutical companies’ willingness to invest in research and development (R&D). Neglecting dependencies between uncertainties of future resistance rates can severely underestimate the systemic risk for certain bug-drug combinations. In this paper, we model the dependencies between several important bug-drug combinations’ resistance rates that are of interest for the United Kingdom probabilistically through copulas. As a commonly encountered challenge in probabilistic dependence modelling is the lack of relevant historical data to quantify a model, we present a method for eliciting dependence information from experts in a formal and structured manner. It aims at providing transparency and robustness of the elicitation results while also mitigating common cognitive fallacies of dependence assessments. Methodological robustness is of particular importance whenever elicitation results are used in complex decisions such as prioritising investments of antibiotics R&D.

Frequency and antimicrobial resistance pattern of bacterial isolates from patients with COVID-19 in two hospitals of Zanjan

Background and Objectives: The outbreak of COVID-19 has been challenging the global health systems. As one of the major associated concerns, microbial co-infections and antimicrobial resistance play critical roles in the prognosis of the disease. This study aims to evaluate co-infections in COVID-19 patients regarding drug resistance. Materials and Methods: A total number of 5530 Real Time PCR-confirmed COVID-19 cases, who were admitted to two major educational Hospitals in Zanjan, Iran, from February 2019 to February 2020 were included. Respiratory, blood and urine specimens were collected and cultured on selective media. Subsequently, isolates identification, disc diffusion suscep- tibility tests, and data analysis were carried out. Results: Bacterial and fungal co-infections were confirmed in 423 patients (8.1%). Co-infections were more prevalent among females (53.2%) than males (46.8%). Coinfected patients had a significantly higher mortality rate compared to those without co-infections (54.8% vs. 12.2%, P<0.001). Acinetobacter baumannii was the most prevalent bacteria isolated from respiratory tract (15.4%) and blood (2.1%). Escherichia coli (12.5%) was the most frequent bacteria in urine. Fungal co-in- fection was confirmed in 174 (3.36%) patients. Gram-negative bacteria were highly sensitive to colistin (97.85%) and wide- ly resistant to cefixime (91.79%) and trimethoprim-sulfamethoxazole (89.64%). Gram-positive bacteria were considerably sensitive to vancomycin (68%) and nitrofurantoin (66%). Tetracycline and ampicillin were the least effective antibiotics for Gram-positive bacteria with respective resistance rates of 90.91% and 83.33%. Conclusion: Given the high incidence of bacterial co-infections in COVID-19 patients, it is important to develop rapid and efficient diagnostic, therapeutic and disinfection guidelines to control these infections in the hospitals.

National trends in hospital, long-term care and outpatient Acinetobacter baumannii resistance rates

Introduction. Acinetobacter baumannii is a top-priority pathogen of the World Health Organization (WHO) and the Centers for Disease Control (CDC) due to antibiotic resistance. Gap Statement. Trends in A. baumannii resistance rates that include community isolates are unknown. Aim. Identify trends in A. baumannii resistance rates across the Veterans Affairs (VA) Healthcare System, including isolates from patients treated in hospitals, long-term care facilities and outpatient clinics nationally. Methodology. We included A. baumannii clinical cultures collected from VA patients from 2010 to 2018. Cultures were categorized by location: VA medical centers (VAMCs), long-term care (LTC) units [community living centers (CLCs)], or outpatient. We assessed carbapenem resistance, multidrug resistance (MDR) and extensive drug resistance (XDR). Time trends were assessed with Joinpoint regression. Results. We identified 19 376 A . baumannii cultures (53% VAMCs, 4% CLCs, 43% outpatient). Respiratory cultures were the most common source of carbapenem-resistant (43 %), multidrug-resistant (49 %) and extensively drug-resistant (21 %) isolates. Over the study period, the number of A. baumannii cultures decreased significantly in VAMCs (11.9% per year). In 2018, carbapenem resistance was seen in 28% of VAMC isolates and 36% of CLC isolates, but only 6% of outpatient isolates, while MDR was found in 31% of VAMC isolates and 36% of CLC isolates, but only 8 % of outpatient isolates. Carbapenem-resistant, multidrug-resistant and extensively drug-resistant A. baumannii isolates decreased significantly in VAMCs and outpatient clinics over time (VAMCs: by 4.9, 7.2 and 6.9%; outpatient: by 11.3, 10.5 and 10.2% per year). Resistant phenotypes remained stable in CLCs. Conclusion. In the VA nationally, the prevalence of A. baumannii is decreasing, as is resistance. Carbapenem-resistant and multidrug-resistant A. baumannii remain common in VAMCs and CLCs. The focus of infection control and antimicrobial stewardship efforts to prevent transmission of resistant A. baumannii should be in hospital and LTC settings.