Clindamycin Resistance Rates Research Articles

Unmasking a looming crisis: Escalating MIC of last resort drugs against MRSA isolates from a tertiary care hospital in Central India

PurposeThe Centers for Disease Control and Prevention has classified methicillin-resistant S aureus (MRSA) as a serious public health threat. The escalating minimum inhibitory concentration (MIC) of standard anti-methicillin-resistant S aureus (MRSA) drugs within the susceptible range, known as "MIC creep," jeopardizes their effectiveness against MRSA infections, posing additional challenges in managing MRSA infections. This cross-sectional study was conducted in a tertiary care hospital in Central India to assess the susceptibility trends of clinical MRSA isolates against commonly used anti-MRSA drugs and to observe MIC creep, if any, over three years (2020–2022). MethodsThe study included 158 non-repetitive clinical MRSA isolates. The MICs of vancomycin, teicoplanin, and linezolid were determined in MRSA strains using agar dilution, while the MIC of daptomycin was performed by broth microdilution. MIC creep was assessed by calculating MIC50, MIC90, Modal MIC, G-mean MIC, and susceptible and resistant percentages for the fiscal years 2020, 2021, and 2022. ResultsOf the 158 MRSA isolates, none were resistant to vancomycin, teicoplanin, and daptomycin, but two showed resistance to linezolid (LRSA). However, fifteen isolates showed intermediate resistance to vancomycin (VISA), and five showed intermediate resistance to teicoplanin (TISA). MIC of these anti-MRSA drugs increased in 2021 and 2022 compared to 2020. G-mean MIC for vancomycin, teicoplanin, and linezolid in MRSA strains increased significantly over the study period, while daptomycin MIC remained relatively stable, with a slight increase in 2021 and 2022. There was a high resistance rate for clindamycin, doxycycline, and chloramphenicol among VISA, TISA, and LRSA isolates compared to MRSA. ConclusionsDuring the three years of the study, “MIC creep” was observed in vancomycin, teicoplanin, and linezolid and, to some extent, for daptomycin in MRSA strains. The recovery of VISA, TISA, and linezolid-resistant MRSAs is worrisome, suggesting possible MRSA treatment failure and being a forerunner of resistant strains.

Tracking trends in the Top End: clindamycin and erythromycin resistance in Group A Streptococcus in the Northern Territory, 2012-2023.

This retrospective study reviewed the macrolide resistance rates of Group A Streptococcus (GAS) isolates in the Northern Territory from 2012 to 2023. Clindamycin and erythromycin resistance rates peaked in 2021, at 6.0% and 12.2% respectively, and then returned to near baseline at 1-2% in 2023. Increased resistance rates were identified in the Top End of Australia from mid-2020, followed 15 months later by high rates in central Australia in 2022. Factors associated with resistant isolates were living in a rural region and of age 18 years and older. Possible explanations include a transient clonal introduction of a resistant GAS strain to the Northern Territory from 2020 to 2022. Ongoing surveillance is required to monitor regional trends and identify temporal variations in resistant isolates.

Antimicrobial Resistance Patterns of Outpatient Staphylococcus aureus Isolates

Oral non-β-lactam antibiotics are commonly used for empirical therapy of Staphylococcus aureus infections, especially in outpatient settings. However, little is known about potential geographic heterogeneity and temporal trends in the prevalence of S aureus resistance to non-β-lactams in the US. To characterize the spatiotemporal trends of resistance to non-β-lactam antibiotics among community-onset S aureus infections, including regional variation in resistance rates and geographical heterogeneity in multidrug resistance. This cross-sectional study used data from Veterans Health Administration clinics collected from adult outpatients with S aureus infection in the conterminous 48 states and Washington, DC, from January 1, 2010, to December 31, 2019. Data were analyzed from January to November 2023. Resistance to lincosamides (clindamycin), tetracyclines, sulfonamides (trimethoprim-sulfamethoxazole [TMP-SMX]), and macrolides. Spatiotemporal variation of S aureus resistance to these 4 classes of non-β-lactam antibiotics, stratified by methicillin-resistant S aureus (MRSA) and methicillin-sensitive S aureus (MSSA), and subdivided by regions of the US (Northeast, Midwest, South, and West). Trend tests and bivariate mapping were used to determine significant changes in resistant proportions over time and identify counties where rates of resistance to multiple non-β-lactams were high. A total of 382 149 S aureus isolates from 268 214 unique outpatients (mean [SD] age, 63.4 [14.8] years; 252 910 males [94.29%]) were analyzed. There was a decrease in the proportion of MRSA nationwide, from 53.6% in 2010 to 38.8% in 2019. Among MRSA isolates, we observed a significant increase in tetracycline resistance (from 3.6% in 2010 to 12.8% in 2019; P for trend < .001) and TMP-SMX resistance (from 2.6% in 2010 to 9.2% in 2019; P for trend < .001), modest and not significant increases in clindamycin resistance (from 24.2% in 2010 to 30.6% in 2019; P for trend = .34), and a significant decrease in macrolide resistance (from 73.5% in 2010 to 60.2% in 2019; P for trend < .001). Among MSSA isolates, significant upward trends in clindamycin, tetracyclines, and TMP-SMX resistance were observed. For example, tetracycline resistance increased from 3.7% in 2010 to 9.1% in 2019 (P for trend < .001). Regional stratification over time showed that the Northeast had slightly higher rates of clindamycin resistance but lower rates of tetracycline resistance, while the South had notably higher rates of resistance to tetracyclines and TMP-SMX, particularly among MRSA isolates. Bivariate mapping at the county scale did not indicate clear regional patterns of shared high levels of resistance to the 4 classes of antimicrobials studied. In this study of outpatient S aureus isolates, MRSA became less common over the 10-year period, and MRSA isolates were increasingly resistant to tetracyclines and TMP-SMX. Geographic analysis indicated no spatial overlap in counties with high rates of resistance to both tetracyclines and TMP-SMX. Examining the regional spatial variation of antibiotic resistance can inform empirical therapy recommendations and help to understand the evolution of S aureus antibiotic resistance mechanisms.

Rising clindamycin resistance in group A Streptococcus in an Irish healthcare institution.

Group A streptococcus (GAS) can cause serious invasive disease in humans with a high mortality rate. An increase in GAS infections was reported in Ireland in 2022, and this increase has been sustained in 2023 and is paralleled by similar trends in Europe. Rising antimicrobial resistance is a global problem and presents significant challenges to clinicians treating GAS infection. There was a reported increase in clindamycin resistance in GAS isolates in Ireland in 2022. We examined antimicrobial susceptibility patterns of GAS isolates in our institution in 2022. Although all GAS isolates included in our study were susceptible to penicillin, we noted a high clindamycin resistance rate of 28 % in our invasive GAS isolates. We also noted high tetracycline and erythromycin resistance, 43 and 30 %, respectively. Our results could have implications for empiric antimicrobial prescribing guidelines for skin and soft tissue infections, which often include clindamycin as it inhibits the production of many virulence factors associated with GAS. In addition, macrolides are often the first line recommended antibiotic for patients with anaphylaxis to penicillin. This study emphasises the importance of continuous surveillance and antimicrobial susceptibility testing of invasive and non-invasive isolates in order to monitor trends in increasing antimicrobial resistance.

Assessing the influence of the COVID-19 pandemic on the incidence, clinical presentation, and clindamycin resistance rates of Streptococcus pyogenes infections

ObjectivesStreptococcus pyogenes (group A Streptococcus [GAS]) is a prevalent cause of community-acquired bacterial infections, with invasive GAS (iGAS) infections presenting severe morbimortality. Clindamycin is generally used based on its antitoxin effect. This study investigates changes in iGAS incidence, clinical presentation, outcomes, and clindamycin resistance in an adult cohort. MethodsThis is a retrospective analysis of S. pyogenes episodes from a tertiary adult hospital in Barcelona (Spain) between 2015 and 2023. The pre-pandemic period includes data from 2015-2019. The pandemic period, from 2020-2021, and post-pandemic period comprised 2022 to the first semester of 2023. ResultsThe global incidence of GAS infections in the pre-pandemic and post-pandemic periods were 2.62 and 2.92 cases per 10.000 hospital admissions, whereas for iGAS cases, they were 1.85 and 2.34. However, a transient decrease was observed during the pandemic period: 1.07 and 0.78 per 10.000 hospital admissions. There was a significant decrease in GAS and iGAS infections during the pandemic period compared with the pre-pandemic incidence (P <0.001 for GAS infections and P = 0.001 for iGAS cases) and the post-pandemic incidence (P = 0.032 for GAS infections and P = 0.037 for iGAS cases). The most common source of infection was skin and soft tissue infections with 264 (54%) cases. Skin and soft tissue infections and cases of necrotizing fasciitis increased during the pandemic. Clindamycin resistance occurred in 13.5% of isolations during the pre-pandemic and 17.5% in post-pandemic period (P = 0.05). ConclusionsOur study revealed a temporary reduction in iGAS infections, followed by resurgence in the post-pandemic period. The observed rise in clindamycin resistance emphasizes the importance of monitoring local resistance patterns for tailored treatment.

Clindamycin Resistance Detection among MRSA at a Tertiary Care Hospital: A Cross-sectional Study

Introduction: Antimicrobial resistance is on the rise, posing a global threat to the success of modern surgical procedures. A common and notorious superbug causing community and hospital-acquired infections is Methicillin-resistant Staphylococcus aureus (MRSA). Its potential for easy and rapid spread leads to increased mortality in hospitals. Clindamycin, a relatively inexpensive and effective drug, is empirically prescribed for the treatment of MRSA infections. Due to the risk of misidentifying clindamycin resistance as susceptibility, leading to treatment failure, its judicious use after D-test is advocated. Aim: To isolate Staphylococcus aureus (S.aureus) from various clinical specimens and to identify MRSA using cefoxitin disc (30 μg), further determining the incidence of inducible clindamycin resistance among MRSA by the disc diffusion method (D-test). Materials and Methods: The present cross-sectional study was conducted in the Department of Microbiology, Government Mohan Kumaramangalam Medical College Hospital (GMKMCH), Salem, Tamil Nadu, India, from June 2023 to August 2023. Study was conducted using 185 S.aureus isolates collected from samples received from patients of all genders treated at the present study hospital. Various clinical samples such as pus, sputum, blood, urine and fluids collected from patients treated at the study Institute Salem during the study period were included. A cefoxitin disc (30 μg) was used to detect MRSA among the 185 S.aureus isolates by disc diffusion method as per Clinical and Laboratory Standards Institute (CLSI) guidelines, which were further tested for clindamycin resistance using clindamycin (2 μg) with erythromycin (15 μg) discs by the D-test. The data of the study were analysed using Statistical Package for the Social Sciences (SPSS) software version 21.0. Further descriptive statistics and a chi-square test with a level of significance, p-value ≤0.005 (statistically significant), were used. Results: Among 185 S.aureus isolates, 130 (70.27%) were Methicillin-sensitive S.aureus (MSSA) and 55 (29.7%) were MRSA. Inducible clindamycin resistance was observed in 22 (40%) isolates, while 17 (30.9%) isolates showed constitutive resistance, 9 (16.36%) showed the MS phenotype, and the remaining 7 (12.72%) showed the susceptible phenotype. Among the clindamycin resistance patterns in MRSA, inducible clindamycin resistance was reported predominantly. Conclusion: The majority of S.aureus was isolated from pus samples, highlighting its importance as a pyogenic microorganism. The current study records a high rate of MRSA resistance among S.aureus isolates. The present study reports a higher rate of inducible clindamycin resistance among MRSA isolates when compared to other phenotypes of clindamycin resistance. Therefore, routine D-testing must be implemented to identify inducible resistance to clindamycin in MRSA to avoid treatment failure.

Antimicrobial resistance rates of urogenital Mycoplasma hominis and Ureaplasma species before and during the COVID-19 pandemic: results from a Greek survey, 2014 to 2022.

The prevalence of antibiotic-resistant urogenital mycoplasmas and ureaplasmas has been gradually increasing over the years, leading to greater concern for accurate diagnosis and treatment. In this study, the antimicrobial resistance trends in Greece were analyzed using 2992 Ureaplasma spp. and 371 M. hominis isolates collected between 2014 and 2022. Antibiotic sensitivity was determined using eight different antimicrobial agents (josamycin, pristinamycin, clindamycin, ofloxacin, azithromycin, tetracycline, erythromycin, and doxycycline), with the data analyzed using descriptive statistical methods. Resistance rates to clindamycin and erythromycin increased for both M. hominis and Ureaplasma spp., while remaining relatively low for Tetracycline, Doxycycline, and Ofloxacin. For Ureaplasma spp., high susceptibility was observed to pristinamycin, tetracycline, doxycycline, azithromycin, and josamycin, and intermediate susceptibility to erythromycin. However, the resistance rate for clindamycin dramatically increased from 60% in 2014 to a peak of 98.46% in 2021, and the erythromycin resistance rate increased from 9.54% in 2018 to 22.13% in 2021. M. hominis exhibited consistently high resistance rates to Erythromycin, while Azithromycin resistance significantly increased over time, from 52.78% in 2017 to 97.22% in 2022. The alarming escalation in antibiotic-resistant urogenital mycoplasmas and ureaplasmas in the Greek population is a significant concern. Antibiotic overconsumption may have played a crucial role in increasing resistance trends. The implementation of nationwide surveillance systems, proper antibiotic stewardship policies, and appropriate culture-based therapy policies are necessary to effectively control this emerging risk.

1626. Group B Streptococcus detection rate and clindamycin resistance among reproductive-age women and early-onset sepsis in neonates in Korea from 2003 to 2022

Abstract Background Group B Streptococcus (GBS) is the leading cause of early-onset sepsis (EOS) in neonates and intrapartum penicillin prophylaxis is recommended for pregnant women with GBS colonization to prevent vertical transmission. For pregnant women with penicillin allergy, clindamycin is recommended. In this study, we retrospectively examined the GBS detection rate and clindamycin resistance rate among Korean women of reproductive age and EOS in neonates in the last 20 years from a single center. Methods From 2003 to 2022, microbiologic studies on genital/rectal swab pairs from females of reproductive age (15-49 years) were reviewed. Among the total number of tests, the number of GBS positive results were extracted and GBS detection rates per year were calculated. Multiple tests from the same person within a year were counted as once. Among the GBS isolates, the clindamycin resistance rate was calculated. The total study period was divided into two periods (period 1 for 2003-2012 and period 2 for 2013-2022) by 10 years and GBS detection rates and clindamycin resistance rates were compared (Chi-square test). EOS caused by GBS in neonates was investigated among all neonates who received sepsis work-up within 3 days after birth. Results For the past 20 years, a total of 14,571 women were tested 16,879 times and GBS was isolated in 1,054 tests (6.2%). GBS detection rate increased from 1.7% (101/6,066) in period 1 to 8.8% (953/10,813) in period 2 (p&amp;lt; 0.001, OR 5.708, 95% CI 4.638-7.025). Among the GBS isolates, clindamycin resistance rates were 29.7% (30/101) in period 1 and 41.1% (392/953) in period 2 (p=0.026, OR 1.654, 95% CI 1.059-2.583). In a separate database, among 9,280 neonates who underwent blood culture or CSF culture studies within 3 days after birth, 9 patients were diagnosed with EOS by GBS and 4 patients died within 30 days. Conclusion Close monitoring is needed on the epidemiology of increasing GBS detection rate and clindamycin resistance rate in GBS isolates from Korean women of reproductive age. Disclosures All Authors: No reported disclosures

Healthcare-associated Staphylococcus aureus infections in children in Turkey: A six-year retrospective, single-center study

Objective: To describe clinical and epidemiological characteristics, antimicrobial susceptibility and mortality-associated factors of healthcare-associated infections (HCAIs) caused by Staphylococcus (S.) aureus in children. Methods: We conducted a retrospective, single-centre study of pediatric HCAIs caused by S. aureus from a tertiary care hospital in Turkey between February 2014 and December 2019. The clinical and epidemiological characteristics and antimicrobial susceptibility of the methicillin-susceptible and methicillin-resistant S. aureus (MSSA and MRSA) isolates was evaluated. Results: A total of 310 pediatric patients were examined. Overall, 225 (72.6%) isolates were MSSA and 85 (27.4%) were MRSA. All S. aureus isolates were susceptible to teicoplanin, vancomycin, linezolid, tigecycline, mupirocin, and daptomycin. Penicillin resistance rates were high (89.0%), while fosfomycin, gentamicin, and clindamycin resistance rates were low (1.3%, 1.0%, and 2.3%, respectively). Except susceptibility to fosfomycin, which was significantly lower in 2014 compared to 2018 and 2019, no significant difference was found in the antimicrobial susceptibility of S. aureus isolates between the years. Baseline characteristics and mortality rate were similar comparing MRSA and MSSA causing HCAIs. The mortality rate of HCAIs caused by S. aureus was 6.5% (20 patients). Malignancy was an independent risk factor associated with mortality in the multivariate analysis (OR 5.446, 95% CI 1.573-18.849). Conclusions: Our findings demonstrate that MSSA remained the most causative agent of HCAIs caused by S. aureus. The mortality rate was 6.5%, the antibiotic resistance rate was quite high for penicillin and diagnosis of malignancy was the main risk factor for increasing mortality in children. These findings could help improve the management of HCAIs caused by S. aureus in children.

P06 Improving antibiotic prescribing practice in a tertiary burns and plastic surgery department

Abstract Background Antimicrobial resistance is an ever-emerging global public health issue. In the healthcare setting, it is essential to use antimicrobials appropriately and manage infections effectively to help tackle antimicrobial resistance. Objectives To review local antibiotic resistance data, update the plastic surgery infection guidelines based on this data, implement interventions to facilitate compliance with the guidelines and re-audit to assess if these interventions have been effective. Methods A review was undertaken of the previous 3 months of antibiotic susceptibility results for significant staphylococci and streptococci species isolated from blood cultures and wound swabs, and the microbiology results of all local cases of necrotizing fasciitis over a 5-year period. The plastic surgery infection guidelines were updated to reflect the changes in local antibiotic resistance rates. Following implementation of the new guideline, various interventions were undertaken including provision of departmental teaching sessions, ensuring availability of appropriate antibiotics in the burns and plastics theatres and redesigning the guideline to include all plastic surgery and infection guidelines within the one document (previously multiple specific guidelines). Between each intervention, compliance with the guideline was measured to establish if the intervention had made a difference. Results Changes to the guideline included using clindamycin rather than doxycycline for the treatment of cellulitis in penicillin allergic patients, as 44% of Group A Streptococcus isolates identified in wound swabs were resistant to doxycycline. Other changes included the introduction of linezolid if the patient had received a recent or failed course of clindamycin, and the use of cefazolin rather than clindamycin for patients with severe cellulitis with a penicillin allergy, due to the increase in rates of clindamycin resistance. After the three intervention cycles, prescriber compliance with the guideline increased from 50% to 71% demonstrating the need for ongoing intervention and re-evaluation. Conclusions Co-amoxiclav and clindamycin were the most commonly prescribed antibiotics in those patients whose antibiotic prescriptions did not comply with the guidelines. The main reason for this is historical usage of these antibiotics within the specialty; this project demonstrates the challenges in changing established practices in individual clinicians. Interventions to ‘make it easy’ for prescribers to follow antibiotic guidelines (for example, the right antibiotic being easily available at the site of prescription), along with targeted education, can be effective but long-standing prescribing habits within specialist areas may be difficult to change.

Superbugs and Bacterial Epidemiology from Wound Infection at Health Institutions in Northeast Ethiopia.

Wound infection plays an important role in the development of chronicity by delaying wound healing, prolonging hospital stay, increasing treatment cost and is responsible for significant morbidity. The aim of this study was to investigate the bacterial epidemiology, multi-drug resistance, and associated risk factors for wound infection at health institutions in Northeast Ethiopia. A facility-based cross-sectional study was conducted from February to April 2021. Demographic, clinical, and risk factor variables were collected using a structured questionnaire. Swabs/pus from wound were collected using sterile applicator swab. Specimens were inoculated on culture media and bacterial isolates were identified using microbiological techniques. Antimicrobial susceptibility test was performed using Kirby-Bauer disc diffusion method. Statistical analysis was done using SPSS software. A total of 229 participants were included in this study. A total of 170 bacterial isolates (74.2%) were isolated. The predominant isolates were S. aureus 80 (47.05%), followed by P. aeruginosa 29 (17.05%), E. coli 22 (12.94%), and Klebsiella spp. 16 (9.41%). Tetracycline (71.7%), clindamycin (15.2%), erythromycin (30.4%), penicillin (80.4%), and co-trimoxazole (80.4%) resistance rates were observed among Gram positive bacterial isolates. The overall prevalence of multi-drug resistance was 71%. Hence, improving the laboratory setup for culture and drug susceptibility testing is recommended for effective treatment of wound infection and to improve infection prevention and control practices in healthcare settings.

Microbiology and Antibiotic Resistance Profiles of Orbital Subperiosteal Abscesses: A Comparison of Pediatric, Adolescent, and Adult Populations.

The purpose of this study was to compare the microbiology and antibiotic resistance profiles of orbital subperiosteal abscesses (SPA) among 3 age cohorts. A retrospective study was conducted at a tertiary care center through a medical record search to identify patients with orbital cellulitis and SPA on imaging from January 1, 2000 to September 10, 2022. Patients were categorized into pediatric (<9 years old), adolescent (9-18 years old), and adult (>18 years old) cohorts. Primary outcomes included culture and antibiotic susceptibility results. Secondary outcomes included antibiotic therapy and surgical intervention. Of the 153 SPA patients included, 62 (40.5%) were in the pediatric cohort (4 months-8 years, mean 5.0 ± 2.7), 51 (33.3%) were adolescent (9-18 years, 12.7 ± 2.8), and 40 (26.1%) were adult (19-95, 51.8 ± 19.3). Viridians group Streptococci were the most frequent organisms isolated across groups. The anaerobic infection rate was higher in the adult compared to the pediatric group (23.0% vs, 4.0%, p = 0.017), while that of the adolescent did not differ significantly from either. Pediatric patients carried a lower rate of clindamycin resistance than adolescent and adult cohorts, who shared similar rates (0 vs. 27.0% and 28.0%, respectively; p = 0.016). There were progressive increases in duration of intravenous antibiotic therapy ( p < 0.195) and rate of surgical intervention ( p < 0.001) going from younger to older cohorts. Organisms isolated from orbital SPA from the past 2 decades demonstrate a predominance of Streptococcal species. Older age may be associated with anaerobic infection, clindamycin resistance, and more aggressive management. Adolescent infections are more similar to adult rather than pediatric counterparts but may require less aggressive management than the former.

Increased frequency of clindamycin-resistant Cutibacterium acnes strains isolated from Japanese patients with acne vulgaris caused by the prevalence of exogenous resistance genes.

Cutibacterium acnes, a resident bacterium of the skin, is a target for antimicrobial treatment of acne vulgaris, because it exacerbates inflammation. Recently, antimicrobial-resistant C. acnes strains have been isolated worldwide, and their prevalence has led to failure of antimicrobial treatment. This study aimed to analyze the antimicrobial resistance of C. acnes strains isolated from Japanese patients with acne vulgaris who visited the hospital and dermatological clinics between 2019 and 2020. Resistance rates to roxithromycin and clindamycin increased during 2019 to 2020 compared with those during 2013 to 2018. Additionally, the proportion of doxycycline-resistant and low-susceptibility strains (minimum inhibitory concentration [MIC] ≥8μg/mL) increased. No difference in clindamycin resistance rates between patients with and without a history of antimicrobial use was observed during 2019 to 2020, which were significantly higher for patients with a history than for patients without a history during 2016 to 2018. The proportion of high-level clindamycin-resistant strains (MIC ≥256 μg/mL) gradually increased; particularly, the resistance rate was 2.5 times higher in 2020 than that in 2013. The proportion of strains showing high-level clindamycin resistance that also have the exogenous resistance genes erm(X) or erm(50), which confer high resistance, showed a strong positive correlation (r=0.82). Strains with the multidrug resistance plasmid pTZC1 encoding erm(50) and tet(W) genes were frequent in clinic patients. Notably, most strains with erm(X) or erm(50) were classified as single-locus sequence types A and F (traditional types IA1 and IA2). Our data show that the prevalence of antimicrobial-resistant C. acnes is increasing in patients with acne vulgaris attributable to acquisition of exogenous genes in specific strains. To control the increasing prevalence of antimicrobial-resistant strains, it is important to select the appropriate antimicrobials while taking into consideration the latest information on resistant strains.

National Surveillance of Tetracycline, Erythromycin, and Clindamycin Resistance in Invasive Streptococcus pyogenes: A Retrospective Study of the Situation in Spain, 2007-2020.

This work reports on antimicrobial resistance data for invasive Streptococcus pyogenes in Spain, collected by the 'Surveillance Program for Invasive Group A Streptococcus', in 2007-2020. emm typing was determined by sequencing. Susceptibility to penicillin, tetracycline, erythromycin, and clindamycin was determined via the E-test. tetM, tetO, msrD, mefA, ermB, ermTR, and ermT were sought by PCR. Macrolide-resistant phenotypes (M, cMLSB, and iMLSB) were detected using the erythromycin-clindamycin double-disk test. Resistant clones were identified via their emm type, multilocus sequence type (ST), resistance genotype, and macrolide resistance phenotype. Penicillin susceptibility was universal. Tetracycline resistance was recorded for 237/1983 isolates (12.0%) (152 carried only tetM, 48 carried only tetO, and 33 carried both). Erythromycin resistance was detected in 172/1983 isolates (8.7%); ermB was present in 83, mefA in 58, msrD in 51, ermTR in 46, and ermT in 36. Clindamycin resistance (methylase-mediated) was present in 78/1983 isolates (3.9%). Eight main resistant clones were identified: two that were tetracycline-resistant only (emm22/ST46/tetM and emm77/ST63/tetO), three that were erythromycin-resistant only (emm4/ST39/mefA-msrD/M, emm12/ST36/mefA-msrD/M, and emm28/ST52/ermB/cMLSB), and three that were tetracycline-erythromycin co-resistant (emm11/ST403/tetM-ermB/cMLSB, emm77/ST63/tetO-ermTR/iMLSB, and emm77/ST63/tetM-tetO-ermTR/iMLSB). Tetracycline, erythromycin, and clindamycin resistance rates declined between 2007 and 2020. Temporal variations in the proportion of resistant clones determined the change in resistance rates.

Microbiological and clinical characteristics of invasive Group B Streptococcal blood stream infections in children and adults from Qatar

IntroductionGroup B Streptococci (GBS) colonize almost one third of human gastrointestinal and genitourinary tracts, particularly in females. The aim of this study is to evaluate the epidemiology, microbiological characteristics, and clinical outcomes of invasive GBS disease in Qatar from all age groups.MethodsA retrospective study was conducted on patients with confirmed GBS blood stream infections during the period between January 2015 and March 2019. Microbiological identification was performed using automated BD PhoenixTM system, while additional antimicrobial susceptibility tests were performed using E test and disc diffusion methods.ResultDuring the four years period, the incidence steadily rose from 1.48 to 2.09 cases per 100.000 population. Out of 196 confirmed cases of invasive GBS infections, the majority were females (63.7%, 125/196) of which 44.8% were pregnant and 53.6% were colonized. Three distinct affected age groups were identified: children ≤ 4 years of age (35.7%), young adults 25–34 (20.9%) and the elderly ≥ 65 year (17.4%). Presenting symptoms were mild with fever in 53% of cases while 89% of cases had Pitt bacteraemia score of ≤ 2. Isolates were universally sensitive to penicillin, ceftriaxone, and vancomycin at 100% but with significant resistance to erythromycin (49%) and clindamycin (28.6%) while 16.8% had inducible clindamycin resistance. Clinical outcomes showed cure rate of 87.25% with complications in (8.76%) and 4% mortality.ConclusionThere is a rising trend of Group B Streptococcal blood stream infections in Qatar with significantly high clindamycin and erythromycin resistance rates. Universal susceptibility rates were demonstrated for penicillin, ceftriaxone, and vancomycin.

Group A Streptococcal Bacteremia: Ten Years' Experience from a Tertiary Care Center in South India.

ABSTRACTBackgroundBacteremia is an uncommon complication of group A streptococcal (GAS) infections. The data on GAS bacteremia is scarce from developing nations such as India.Patients and methodsWe performed a retrospective analysis of patients diagnosed with GAS bacteremia in a tertiary care hospital in Kerala, India over a 10-year period (2012–2021) by review of the electronic medical records (EMRs).ResultsA total of 58 cases of GAS bacteremia were identified in the study period. Skin/soft tissue infection was the most common source of bacteremia. A total of 34.4% of the patients required ICU admission and the in-hospital mortality was 22.4%. All the GAS isolates were sensitive to penicillin, ampicillin, and ceftriaxone. Erythromycin and clindamycin resistance was seen in 39.7% and 24.1% isolates, respectively.ConclusionThis study shows that despite advancement in medical sciences, GAS bacteremia remains as a disease with high morbidity and mortality. A higher rate of clindamycin resistance was observed compared to previous Indian studies.How to cite this articleJayakumar JS, Niyas VKM, Arjun R. Group A Streptococcal Bacteremia: Ten Years’ Experience from a Tertiary Care Center in South India. Indian J Crit Care Med 2022;26(9):1019–1021.

Antibiotic resistance rates and penicillin MIC distribution in patients with streptococcal pneumonia between 2013-2019, and use of antibiotics in clinical practice

PurposeThe purpose of the present study is to investigate the antibiotic resistance rates and use of antibiotics in patients with streptococcal pneumonia in a reference tertiary care hospital for pulmonary diseases in Izmir, Turkey. MethodsA total of 1224 cases with streptococcal pneumonia between 2013 and 2019 were included in the study, retrospectively. Drug susceptibility testing for penicillin and other antibiotics were performed according to the recommendations of EUCAST criteria. Clinical data and general characteristics were collected and evaluated for each patient in accordance with the susceptibility testing report. ResultsTotally, resistance rates for trimethophrim-sulfamethoxazole, penicillin (oxacillin), erythromycin, tetracycline, clindamycin and levofloxacin resistance were 63.5%, 39.8%, 37.7%, 37.6%, 28.8%, and 4.8%, respectively. Antibiotic resistance was not detected against vancomycin,teicoplanin and linezolid. Multidrug resistance rate was found to be 27.1%. It was observed that there was a statistically significant decrease in trimethophrim-sulfamethoxazole, penicillin (oxacillin), erythromycin, clindamycin and levofloxacin resistance rates by years (p: 0.000, 0.004, 0.000, 0.001, 0.010, respectively). The penicillin MIC distribution was higher at the range of 0.12–2 ​μg/mL and there was statistical difference among the ranges of MIC values for the representative years (p:0.033). Among the antibiotics investigated, the most commonly used antibiotic was moxifloxacin. ConclusionsTrimethophrim-sulfamethoxazole resistance rate has been found higher than other antibiotics. As penicillin MIC values were at the range of 0.12–2 ​μg/mL frequently, high doses of penicillin treatment might be required in some patients. It is noteworthy that significant decrease in resistance rates in penicillin, erythromycin, clindamycin and tetracycline could be due to the vaccination programme carried out since 2008 in Turkey. As the empiric use of quinolones is high it would be more appropriate to use it according to the susceptibility testing. It is important to determine the regional antimicrobial susceptibility for Streptococcus pneumoniae to select appropriate empirical antimicrobials in the clinical practice.

CHARACTERIZATION OF STAPHYLOCOCCUS AUREUS ISOLATED FROM BURN WOUND; STRONG ANTIBACTERIAL ACTIVITY OF PHAGE COCKTAIL AGAINST VANCOMYCIN INTERMEDIATE-RESISTANT STAPHYLOCOCCUS AUREUS

A universal problem is about spread of Staphylococcus aureus infections in burn patients. The present study aimed to learn about the molecular characteristics and the resistance pattern of S. aureus strains isolated from burn patients. In this cross-sectional study, we investigated 100 unique S. aureus isolated from burn patients by antimicrobial activity and biofilm formation and evaluated the effect of Complex Pyobacteriophage, a commercial bacteriophage cocktail, against the isolates mentioned above. Methicillin-resistant Staphylococcus aureus (MRSA) comprised 76%, and methicillin-susceptible Staphylococcus aureus (MSSA) comprised 24% of 100 S. aureus strains. The resistance rate among MRSA isolates was higher than compared of MSSA. Mupirocin resistance was found in 30% of isolates, with 28 (93.3%) and 2 (6.7%) strains of MRSA and MSSA, respectively, found. Vancomycin intermediate resistance in S. aureus (VISA) was 13% of MRSA strains. Two isolates were confirmed as vancomycin-resistant S. aureus (VRSA) strains and carried vanA. 31 and 62% of the total isolates showed inducible and constitutive resistance phenotypes. The rate of inducible and constitutive clindamycin resistance among MRSA strains was higher than MSSA strains. Biofilm production was detected in 66% of isolates. Strong, moderate, and weak producers accounted for 25%, 17%, and 24% of isolates. Phage analysis showed that 81% were susceptible to the phage cocktail, and only 19% were resistant to the phage cocktail. Our data indicated that VISA strains prevalence in the burn unit was mainly from S. aureus infections. Present work recommended that vancomycin treatment be closely monitored to prevent the spread of VISA and VRSA strains. Observations also highlighted the role of bacteriophage cocktails in eradicating S. aureus-related infections.

Distribution of erm genes among MRSA isolates with resistance to clindamycin in a Chinese teaching hospital.

The objective of this study was to analyze erythromycin and clindamycin resistance patterns among different MRSA lineages in China. Antimicrobial susceptibility testing, resistance determinant screening, plasmid electroporation and sequence comparisons were performed. High rates of clindamycin (92.5%, 270/292) and erythromycin (92.8%, 271/292) resistance were observed. Additionally, 88.2% (60/68) of the ST59 MRSA isolates and 78.9% (15/19) of the ST239 MRSA isolates had constitutive resistance to clindamycin, while 82.0% (123/150) of the ST5 MRSA isolates showed inducible clindamycin resistance. The ermB gene was identified in 80.9% (55/68) of the ST59 isolates but was not detected in ST5 and ST239 MRSA isolates. Detection rates of ermA were high in the ST5 (99.3%, 149/150) and ST239 (89.5%, 17/19) MRSA isolates, but no ermA-positive ST59 MRSA isolates were identified. The ermC gene, observed to be harbored on similar, transmissible plasmids ranging in size from 2402 to 2473bp, were found in different MRSA lineages. Summarily, high erythromycin and clindamycin resistance rates were observed in MRSA isolates. ST59 and ST239 MRSA isolates primarily exhibited constitutive resistance, while ST5 MRSA isolates showed inducible resistance phenotypes. ermA and ermB genes were frequently carried by specific MRSA clones, while ermC gene was present within small transmissible plasmids in all lineages. Erythromycin and clindamycin resistance genes transfer between MRSA isolates in healthcare settings remains a problem, and infection control procedures should be applied.

Antimicrobial resistance in colonizing group B Streptococcus among pregnant women from a hospital in Vietnam

Few studies have been conducted on group B Streptococcus (GBS) in Vietnam. We determined the GBS colonization and antimicrobial resistance vaginal-rectal profile of 3863 Vietnamese pregnant women over 5 years. Maternal GBS colonization was characterized by antibiotic susceptibility. Overall, the GBS colonization rate was 8.02% (95% CI: 7.20–8.94%). Compared to sampling ≥ 35 weeks of gestation, the GBS colonization rate was statistically higher (p = 0.004) with sampling < 35 weeks. Among 272 antimicrobial susceptibility testing isolates, all were susceptible to ampicillin, penicillin, ceftriaxone, cefotaxime, vancomycin, and quinupristin/dalfopristin. Resistance was highest for tetracycline (89.66%), followed by erythromycin (76.23%) and clindamycin (58.21%). Multidrug resistance and resistance to ≥ 6 different antibiotics were 60.66% and 8.82%, respectively. Resistance to clindamycin but not erythromycin (L phenotype) was 2.2%. The clindamycin resistance rate was significantly increased (p = 0.005) during the study period. These data demonstrate a low rate of maternal GBS colonization. The high rate of erythromycin, clindamycin, and multidrug resistance to GBS that can be transmitted to neonates is an important risk factor to consider. β-lactams continue to be appropriate for first-line treatment and prophylaxis in the study area. Ongoing monitoring should be considered in the future.