Erythromycin Resistance Rates Research Articles

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.

Molecular characteristics and antimicrobial resistance of invasive pneumococcal isolates from children in the post-13-valent pneumococcal conjugate vaccine era in Shenzhen, China

This study aimed to evaluate the molecular epidemiology and antimicrobial resistance of invasive pneumococcal isolates from children in Shenzhen, China, in the early stage of the pneumococcal 13-valent conjugated vaccine (PCV-13) era from 2018 to 2020. Invasive pneumococcal strains were isolated from hospitalized children with invasive pneumococcal diseases (IPDs) from January 2018 to December 2020. The serotype identification, multilocus sequence typing (MLST), and antibiotic susceptibility tests were performed on all culture-confirmed strains. Sixty-four invasive strains were isolated mainly from blood (70.3%). Prevalent serotypes were 23F (28.1%), 14 (18.8%), 19F (15.6%), 6A/B (14.1%), and 19A (12.5%), with a serotype coverage rate of 96.9% for PCV13. The most common sequence types (STs) were ST876 (17.1%), ST271 (10.9%), and ST320 (7.8%). Half of the strains were grouped in clonal complexes (CCs): CC271 (21.9%), CC876 (20.3%), and CC90 (14.1%). Meningitis isolates showed a higher resistance rate (90.9% and 45.5%) to penicillin and ceftriaxone than the rate (3.8% and 9.4%) of non-meningitis isolates. The resistance rates for penicillin (oral), cefuroxime, and erythromycin were 53.13%, 73.4%, and 96.9%, respectively. The dual ermB and mefA genotype was found in 81.3% of erythromycin-resistant strains. The elevated minimum inhibitory concentration (MIC) of β-lactam antibiotics and dual-genotype macrolide resistance were related mainly to three major serotype-CC combinations: 19F-CC271, 19A-CC271, and 14-CC876. Invasive pneumococcus with elevated MICs of β-lactams and increased dual ermB and mefA genotype macrolide resistance were alarming. Expanded PCV13 vaccination is expected to reduce the burden of paediatric IPD and to combat antibiotic-resistant pneumococcus in Shenzhen.

Determination of Capsule Types, Antibiotic Resistance Profiles and Phylogenetic Relationships of Group B Streptococcus Isolates Isolated from Patients Followed in Various Clinics and Polyclinics

Group B streptococci (GBS) are microorganisms that cause various systemic infections. In this study, it was aimed to investigate the capsule serotypes, antibiotic resistance and phylogenetic similarity relationship between GBS isolates. One hundred and ten GBS isolates isolated from female patients who admitted to Adana City Hospital with various complaints were included in the study. Kirby-Bauer disc diffusion method was used for the antibiotic resistance patterns and evaluated with CLSI criteria. The genes ermB, ermTR, mefA for erythromycin resistance and linB genes for clindamycin resistance were investigated by multiplex PCR method. Multiplex PCR method was used for GBS capsule serotyping. Similarity relationship between the isolates was analyzed by pulsed-field gel electrophoresis (PFGE) method. As a result of the study; all strains were found to be sensitive to penicillin and vancomycin. Erythromycin, clindamycin ofloxacin, and ceftriaxone resistance rates were observed as 60%, 11.8%, 6.4%, and 4.5%, respectively. The mefA gene was not found while 53% and 47% of the erythromycin-resistant isolates carried ermTR and ermB genes, respectively. The linB gene was not found in clindamycin-resistant GBS isolates. The capsule serotype distributions of GBSs were found as, Ib 42.7%, Ia 35.5%, III 10%, II 8.2%, and V 3.6%, respectively. In the analysis of the similarity relationships between GBS isolates with the PFGE method, no significant relationship was found. In conclusion, it was thought that more studies should be conducted to show the prevalence of GBS capsule serotypes and patterns of antibiotic resistance.

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.

Genomic Analysis of Group B Streptococcus Carriage Isolates From Botswana Reveals Distinct Local Epidemiology and Identifies Novel Strains.

In pregnant people colonized with group B Streptococcus (GBS) in Botswana, we report the presence/expansion of sequence types 223 and 109, a low rate of erythromycin resistance, and 3 novel sequence types. These data highlight the importance of local epidemiologic studies of GBS, a significant source of neonatal disease.

The association between farm-level antimicrobial usage and resistance of Staphylococcus spp., as the major genus isolated from aerosol samples, in Japanese piggeries.

Bacteria are the dominant particulate matter in livestock houses and can threaten animal and public health. Antimicrobial resistance (AMR) is a crucial concern worldwide, and nationwide measures established based on the One Health approach are being implemented in many countries. This requires multidisciplinary perspectives and collaboration among the human, animal, and environmental sectors. However, information on the AMR risk in livestock house aerosol is limited, especially its association with antimicrobial usage (AMU). Therefore, this study was conducted to reveal the AMR profile of Staphylococcus, the major bacterial genus in the aerosol of the piggeries of Japanese farms, and the association between farm-level AMU and AMR. The investigation at 10 farrow-to-finish pig farms revealed that regardless of the sampling season and the piggery group, the resistance rate of isolated staphylococci for oxacillin, erythromycin, and lincomycin was more than 40% of the median and tended to be higher than that for other antimicrobials. The AMU adjusted by the defined daily dose (DDD-adjusted AMU) in the fattening piggery group was significantly higher than that in the sow piggery group (p < 0.05). Finally, for the fattening piggery group, the generalized linear mixed model revealed that the AMR rate for oxacillin, erythromycin, tetracycline, and chloramphenicol was positively associated with the corresponding class-based DDD-adjusted AMU of penicillins (odds ratio (OR) = 2.63, p = 0.03), macrolides (OR = 6.89, p = 0.0001), tetracyclines (OR = 2.48, p = 0.04), and amphenicols (OR = 3.22, p = 0.03), respectively. These significant positive associations observed in this study imply that the resistance rate for these antimicrobials may decrease by reducing the corresponding antimicrobials' use. In addition, the resistance rates for erythromycin and chloramphenicol also displayed a positive association with the AMU of antimicrobial classes other than macrolides and amphenicols, respectively. The mechanism underlying these phenomena is unclear; therefore, further evaluation will be needed. As limited studies have reported staphylococci in piggery aerosol and its AMR with quantitative AMU, these results based on on-farm investigations are expected to aid in establishing countermeasures for AMR of aerosol bacteria in pig farms.

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.

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.

550. Analysis of Staphylococcus aureus resistance patterns and antibiotic prescribing practices in a single tertiary pediatric center in South Florida

Abstract Background Staphylococcus aureus antibiotic resistance in pediatric populations is a dynamic problem that affects the morbidity and mortality of all children. Local efforts to understand its patterns as well as the antibiotic prescribing trends, as well as their relationship, are cornerstone for the development of mitigation strategies. Methods We conducted a retrospective observational study of 11,964 clinical isolates at a tertiary pediatric care center in South Florida collected from 2008 to 2019 to determine the antibiotic susceptibility of Staphylococcus aureus, compare antibiotic resistance patterns between MRSA and MSSA isolates and evaluate antibiotic prescribing practices from 2013 to 2019. Results Methicillin resistance was present in 47.9% (±0.63) isolates with no significant temporal trend. Resistance to clindamycin was on average 24.8% (±1.08), to erythromycin 66.9% (±1.68), to levofloxacin 35.5% (±1.61) and to gentamicin 6.8% (±1.11). MRSA isolates had higher resistance rates to most antibiotics than MSSA (p&amp;lt; 0.05) except for clindamycin for which both had similar rates. Resistance to clindamycin and gentamicin increased significantly from 20% to 25% and from 5 to 15%, respectively, among MRSA and quinolone resistance rose among MSSA from 7% to 13%. Antibiotic prescription rate increased from 56 prescriptions per 1,000 patients to 136 prescriptions per 1,000 patients from 2013 to 2019. There was a positive correlation between erythromycin resistance rate among MRSA and macrolide prescription frequency (p&amp;lt; 0.05). Figure 1.Antibiotic resistance in S aureus isolates from pediatric patients between 2008 and 2019. The trends in erythromycin and gentamicin resistance were statistically significant (p&amp;lt;0.05); all other trends shown were not significant. Figure 2.Comparative annual resistance rate among MSSA and MRSA isolates from pediatric patients between 2008 and 2019 The trend in levofloxacin resistance among MSSA was statistically significant, as well as the trends in erythromycin, clindamycin, and gentamicin in MRSA; all other trends were not significant. Figure 3.Annual antibiotic prescription frequency as a percent of all antibiotics prescribed in outpatient facilities and emergency department at Nicklaus Children’s Hospital between 2013 and 2019Beta-Lactams are expressed as the summation of cephalosporins and penicillins. The frequency at which penicillins, cephalosporins and macrolides were prescribed changed significantly; all other frequencies did not change significantly. Conclusion Pediatric Staphylococcus aureus isolates showed high and stable rates of methicillin resistance during the study period. There is growing clindamycin and gentamicin resistance among MRSA isolates as well as increasing levofloxacin resistance in MSSA isolates. Antibiotic prescribing increased significantly in this population during the study period in South Florida. Disclosures All Authors: No reported disclosures.

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.

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.

A Cross-Sectional Study Revealing the Emergence of Erythromycin-Resistant Bordetella pertussis Carrying ptxP3 Alleles in China.

BackgroundPrevious limited studies have identified that Bordetella pertussis (B. pertussis) isolates circulating in China possess distinct molecular features and high rates of erythromycin-resistance (ER). Their evolution and potential impact on the prevention and control of global pertussis are worthy of attention.MethodsThe present cross-sectional study involved 311 non-duplicate and unrelated B. pertussis strains isolated from Chinese children from 2017 to 2019. Their antimicrobial susceptibilities were assessed using both E-test strips and Kirby-Bauer (KB) disk diffusion methods. Seven virulence-related genes (ptxA, ptxC, ptxP, prn, fim2, fim3, and tcfA2) and the A2047G mutation in the 23S rRNA gene were detected by PCR. Based on the susceptibilities and genotypes, 50 isolates were selected for multi-locus variable-number tandem-repeat analysis (MLVA) typing and whole-genome sequencing.ResultsA total of 311 B. pertussis strains were isolated from children with a median age of 4 months (interquartile range: 2–9 months). Strains carrying the ptxP1 allele were more frequent (84.9%, 264/311), were always ER (except for one strain), and were mainly related to ptxA1/ptxC1/prn1 alleles (99.6%, 263/264). The remaining 47 (15.1%) strains carried the ptxP3 allele, mainly harboring the ptxA1/ptxC2/prn2 alleles (93.6%, 44/47), and were sensitive to erythromycin (except for two strains). The two ER-ptxP3 isolates were first identified in China, belonged to MT27 and MT28 according to MLVA, and were classified into sub-lineage IVd by phylogenetic analysis of their genome sequences. This sub-lineage also includes many strains carrying the ptxP3 allele spreading in developed countries. For each tested antimicrobial, the susceptibilities judged by KB disks were consistent with those determined by E-test strips.ConclusionThe present results reveal that B. pertussis strains with the ptxP1-ER profile still dominate in China, and a few strains carrying the ptxP3 allele have acquired the A2047G mutation in the 23S rRNA gene and the ER phenotype. The surveillance of the drug susceptibility of B. pertussis is necessary for all countries, and the KB disk method can be adopted as a screening test.

Antibiotic resistance among clinical Ureaplasma isolates from Cuban individuals between 2013 and 2018.

Introduction. Acquired resistance against the antibiotics that are active against Ureaplasma species has been described.Hypothesis/Gap Statement. Diagnostics combined with antimicrobial sensitivity testing are required for therapeutic guidance.Aim. To report the prevalence of antimicrobial resistance among Cuban Ureaplasma isolates and the related molecular mechanisms of resistance.Methodology. Traditional broth microdilution assays were used for antimicrobial sensitivity testing in 262 clinical Ureaplasma species isolates from Cuban patients between 2013 and 2018, and a subset of samples were investigated in parallel with the commercial MYCO WELL D-ONE rapid culture diagnostic assay. The underlying molecular mechanisms for resistance were determined by PCR and sequencing for all resistant isolates.Results. Among the tested isolates, the tetracycline and erythromycin resistance rates were 1.9 and 1.5%, respectively, while fluoroquinolone resistance was not found. The tet(M) gene was found in all tetracycline-resistant isolates, but also in two tetracycline-susceptible Ureaplasma clinical isolates. We were unable to determine the underlying mechanism of erythromycin resistance. The MYCO WELL D-ONE kit overestimated tetracycline and erythromycin resistance in Ureaplasma spp. isolates.Conclusions. Although low levels of antibiotic resistance were detected in Cuban patients over a 5-year period, continued surveillance of the antibiotic susceptibility of Ureaplasma is necessary to monitor possible changes in resistance patterns.

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.

Bacterial Etiologies of Ear Infection and Their Antimicrobial Susceptibility Pattern at the University of Gondar Comprehensive Specialized Hospital, Gondar, Northwest Ethiopia: A Six-Year Retrospective Study.

BackgroundAn ear infection is responsible for up to 40% of preventable hearing impairment; one of the reasons for frequent and unwise antibiotic usage, especially in the developing world. Since the incidence of antibiotic resistance is increasing, especially in resource-limited countries, up-to-date knowledge on the susceptibility of ear-discharge isolates to antibiotic is important for better patient treatment. Therefore, this study aimed at determining the bacterial etiologies and their antibiotic susceptibility profiles among patients suspected with ear infections.MethodsWe collected retrospective data from bacteriological results of ear discharge samples from 2013 to 2018. Sample collection, culture preparation, and bacterial identification were performed using standard microbiological techniques. Antimicrobial susceptibility testing was performed following Clinical and Laboratory Standard Institute (CLSI) guidelines. We extracted and inputted the data using Epi-info version 7 and exported it to SPSS version 20 for analysis.ResultsThe overall ear-discharge culture positivity rate was 283/369 (76.7%) (95% CI = 72.4–81.3), with 14/283 (4.95%) mixed infections. Staphylococcus aureus (27.9%), Proteus spps (20.8%), Streptococcus spps (10%), and Pseudomonas spps (8.92%) were the main isolates. High-level resistance rates for tetracycline (77.6%), penicillins (67.2%), erythromycin (52.6%), and co-trimoxazole (52%), and low-level resistance rates for fluoroquinolones (23.3%), aminoglycosides (23.7%), and cephalosporins (29.8%) were observed. More than 45% of isolates, with 50.9% of Gram-negative and 37.3% of Gram-positive, were multidrug-resistant.ConclusionStaphylococcus aureus, Proteus mirabilis, Proteus vulgaris, Escherichia coli, and Pseudomonas aeruginosa were the leading cause of ear infections. The presence of high number of multidrug-resistant strains calls for the need for periodic and continuous follow-up of antibiotic usage in the study area. Further studies are recommended to explore the types of ear infections, with their etiologic agents and possible risk factors.

Changing characteristics of S. aureus bacteremia caused by PVL-negative, MRSA strain over 11\xa0years

Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) has emerged as an important cause of infection. We conducted a longitudinal study to evaluate changes in clinical and microbiological characteristics as well as outcomes of sequence type (ST) 72 MRSA bacteremia. We reviewed adult patients enrolled in a prospective cohort with ST72 MRSA bacteremia from August 2008 to December 2018 at Asan Medical Center, Seoul, South Korea. Changes in clinical characteristics, outcomes, and microbiological characteristics of patients over time were evaluated. Generalized linear and linear regression models were used to evaluate changes. Of the 1,760 isolates, 915 (62%) were MRSA bacteremia and 292 (31.9%) were ST72 MRSA. During the study period, the relative risk (RR) of MRSA bacteremia decreased annually by 3.7%; however, among MRSA bacteremia, RR of ST72 MRSA increased annually by 8.5%. Vancomycin minimum inhibitory concentration (MIC) decreased over the study period. Metastatic infection, persistent bacteremia, and recurrence of bacteremia within 12 weeks decreased significantly. There were no significant changes in 30-d and 12-week mortality. Antibiotic susceptibility of ST72 MRSA was evaluated, and the resistance rate to erythromycin decreased significantly. ST72 MRSA incidence increased annually; its vancomycin MIC and erythromycin resistance rate decreased over the 11 years.

Invasive Streptococcus pyogenes disease in Spain: a microbiological and epidemiological study covering the period 2007-2019.

The aim of this study is to present the first nationwide microbiological and epidemiological study of invasive group A Streptococcus (iGAS) disease in Spain. One thousand eight hundred ninety-three iGAS isolates were analyzed over 2007-2019. emm typing was performed by sequencing the gene's variable 5' end, exotoxin genes were identified by PCR, and antimicrobial susceptibility explored via the E test and disk diffusion. Five hundred twenty-three isolates were associated with sepsis, 292 with cellulitis, 232 with scarlet fever, 153 with pneumonia, 141 with streptococcal toxic shock syndrome, and 94 with necrotizing fasciitis. The most prevalent emm types were emm1 (449/1893 isolates), emm89 (210/1893), emm3 (208/1893), emm4 (150/1893), emm12 (112/1893) emm6 (107/1893), emm87 (89/1893), emm28 (88/1893), emm75 (78/1893), emm77 (78/1893), emm11 (58/1893), and emm22 (35/1893). emm1, emm3, emm4, and emm6 were the predominant types affecting children (mostly respiratory infections), while emm11, emm77, and emm89 prevailed in the elderly (mostly skin infections). Each emm type was associated with one or more exotoxin gene (spe, sme, and ssa) profiles. speA was detected in 660 isolates, speB in 1829, speC in 1014, speF in 1826, speG in 1651, speJ in 716, speH in 331, smeZ in 720, and ssa in 512. Isolates with speA were associated with the most severe infections. Penicillin susceptibility was universal. Two hundred twenty-four isolates were resistant to tetracycline, 169 to erythromycin, and 81 to clindamycin. Tetracycline, erythromycin, and clindamycin resistance rates declined over the study period. The above information could serve as the basis for continued surveillance efforts designed to control disease cause by this bacterium.

Antimicrobial Resistance Profiles and Macrolide Resistance Mechanisms of Campylobacter coli Isolated from Pigs and Chickens.

We identified 1218 Campylobacter coli isolates from fecal and carcass samples of pigs (n = 643) and chickens (n = 575) between 2010 and 2018. About 99% of the isolates were resistant to at least one antimicrobial agent. The isolates exhibited high resistance rates (>75%) to ciprofloxacin, nalidixic acid, and tetracycline. Azithromycin and erythromycin resistance rates were the highest in isolates from pigs (39.7% and 39.2%, respectively) compared to those of chickens (15.8% and 16.3%, respectively). Additionally, a low-to-moderate proportion of the isolates were resistant to florfenicol, gentamicin, clindamycin, and telithromycin. Multidrug resistance (MDR) was found in 83.1% of the isolates, and profiles of MDR usually included ciprofloxacin, nalidixic acid, and tetracycline. We found point mutation (A2075G) in domain V of the 23S rRNA gene in the majority of erythromycin-resistant isolates. Multilocus sequence typing of 137 erythromycin-resistant C. coli isolates revealed 37 previously reported sequence types (STs) and 8 novel STs. M192I, A103VI, and G74A substitutions were frequently noted in the ribosomal proteins L4 or L22. Further, we identified a considerable proportion (>90%) of erythromycin-resistant isolates carrying virulence factor genes: flaA, cadF, ceuE, and VirB. The prudent use of antimicrobials and regular microbiological investigation in food animals will be vital in limiting the public health hazards of C. coli in Korea.

Genomic analysis of the diversity, antimicrobial resistance and virulence potential of clinical Campylobacter jejuni and Campylobacter coli strains from Chile.

Campylobacter jejuni and Campylobacter coli are the leading cause of human gastroenteritis in the industrialized world and an emerging threat in developing countries. The incidence of campylobacteriosis in South America is greatly underestimated, mostly due to the lack of adequate diagnostic methods. Accordingly, there is limited genomic and epidemiological data from this region. In the present study, we performed a genome-wide analysis of the genetic diversity, virulence, and antimicrobial resistance of the largest collection of clinical C. jejuni and C. coli strains from Chile available to date (n = 81), collected in 2017–2019 in Santiago, Chile. This culture collection accounts for more than one third of the available genome sequences from South American clinical strains. cgMLST analysis identified high genetic diversity as well as 13 novel STs and alleles in both C. jejuni and C. coli. Pangenome and virulome analyses showed a differential distribution of virulence factors, including both plasmid and chromosomally encoded T6SSs and T4SSs. Resistome analysis predicted widespread resistance to fluoroquinolones, but low rates of erythromycin resistance. This study provides valuable genomic and epidemiological data and highlights the need for further genomic epidemiology studies in Chile and other South American countries to better understand molecular epidemiology and antimicrobial resistance of this emerging intestinal pathogen.