Isolates Of Streptococcus Research Articles

Ceftriaxone 1g versus 2g per day, for the treatment of community-acquired pneumonia: a retrospective cohort study.

Guidelines recommend intravenous (IV) ceftriaxone at a dose of 1-2g/d as empirical treatment in adults hospitalized with community acquired pneumonia (CAP), with the addition of macrolide. We examined whether 1g/d of IV ceftriaxone is associated with similar clinical outcomes to those of 2g/d. This is a single-center, retrospective, cohort study of all adult patients hospitalized at Rabin Medical Center between 2015 and 2018 with CAP. The primary outcome was 30-day all-cause mortality. Risk factors for 30-day all-cause mortality were identified by univariable and multivariable analyses, using logistic regression analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. A total of 2045 patients were treated with IV ceftriaxone 1g/d and were and compared to 1944 patients who were treated with 2g/d. The groups were comparable in their baseline characteristics and their clinical presentation. The 30-day all-cause mortality rate was similar between the groups (301/2045 (14.7%) for 1g/d vs. 312/1944 (16.0%) for 2g/d, p = 0.24). The rate of C. difficile infection (CDI) was significantly decreased with 1g/d compared to 2g/d (4/2045 (0.2%) vs. 12/1944 (0.6%), p = 0.03) and the length of stay was significantly shorter (median 4days interquartile range (IQR) 3-7 vs. 5days IQR 3-8, p = 0.02). None of the blood isolates of Streptococcus pneumoniae were penicillin or ceftriaxone resistant. For hospitalized patients with CAP, IV ceftriaxone 1g/d was associated with similar mortality rates as IV ceftriaxone 2g/d, with a decreased rate of CDI and shorter length of stay. Ceftriaxone 1g/d may be sufficient to treat patients with CAP in countries with low prevalence of drug resistant Streptococcus pneumoniae.

Diversity of Streptococcus spp. and genomic characteristics of Streptococcus uberis isolated from clinical mastitis of cattle in Bangladesh.

Streptococci are the major etiology in mastitis in dairy cattle, a cause of huge economic losses in the dairy industries. This study was aimed to determine the diversity of Streptococcus spp. isolated from clinical mastitis of cattle reared in Bangladesh. A total of 843 lactating cattle reared in four prominent dairy farms and one dairy community were purposively included in this study where 80 cattle were positive to clinical mastitis (CM) based on gross changes in the udder (redness, swelling, and sensitive udder) and/or milk (flakes and/or clots). Milk samples were collected from all the eighty cattle with clinical mastitis (CCM) and twenty five apparently healthy cattle (AHC). Samples were enriched in Luria Bertani broth (LB) and one hundred microliter of the enrichment culture was spread onto selective media for the isolation of Staphylococcus spp., Streptococcus spp., Enterococcus spp., Escherichia coli and Corynebacterium spp., the major pathogen associated with mastitis. Isolates recovered from culture were further confirmed by species specific PCR. Out of 105 samples examined 56.2% (59/105), 17.14% (18/105), 9.52% (10/105) and 22.9% (24/105) samples were positive for Staphylococcus, Streptococcus, Enterococcus faecalis and E. coli, respectively. This study was then directed to the determination of diversity of Streptococcus spp. through the sequencing of 16S rRNA. A total of eighteen of the samples from CCM (22.5%) but none from the AHC were positive for Streptococcus spp. by cultural and molecular examination. Sequencing and phylogenetic analysis of 16S rRNA identified 55.6, 33.3, 5.6 and 5.6% of the Streptococcus isolates as Streptococcus uberis, Streptococcus agalactiae, Streptococcus hyovaginalis and Streptococcus urinalis, respectively. Considering the high prevalence and worldwide increasing trend of S. uberis in mastitis, in-depth molecular characterization of S. uberis was performed through whole genome sequencing. Five of the S. uberis strain isolated in this study were subjected to WGS and on analysis two novel ST types of S. uberis were identified, indicating the presence of at least two different genotypes of S. uberis in the study areas. On virulence profiling, all the isolates harbored at least 35 virulence and putative virulence genes probably associated with intramammary infection (IMI) indicating all the S. uberis isolated in this study are potential mastitis pathogen. Overall findings suggest that Streptococcus encountered in bovine mastitis is diverse and S. uberis might be predominantly associated with CM in the study areas. The S. uberis genome carries an array of putative virulence factors that need to be investigated genotypically and phenotypically to identify a specific trait governing the virulence and fitness of this bacterium. Moreover, the genomic information could be used for the development of new genomic tools for virulence gene profiling of S. uberis.

A Multicenter Evaluation of Overall Susceptibility and Antimicrobial Resistance Among Streptococcus pneumoniae Isolates.

S. pneumoniae ranks as the fourth-most lethal pathogen globally in terms of fatalities associated with or attributable to resistance. In this study, the Antimicrobial Testing Leadership and Surveillance (ATLAS) analysis from India aims to study the overall antimicrobial susceptibility (AMS) among pneumococcal isolates collected between 2018 and 2021. Non-duplicate clinically significant S. pneumoniae isolates were collected between 2018 and 2021. In vitro activity of antibiotics was assessed against S. pneumoniae. Susceptibility was confirmed at an International Health Management Associates (IHMA) laboratory using supplied broth microdilution panels (Omron Microscan Systems, Inc., Omron Corp., Kyoto, Japan), according to the Clinical and Laboratory Standards Institute (CLSI) guidelines for all antibiotics. Of the total 86 non-duplicate isolates of Streptococcus pneumoniae collected from the tertiary care centers, the proportion of isolates increased from 8.14% (n=7) in 2018 to 43.02% (n=37) in 2020. Most isolates (n = 18; 48.65%) were collected from the age group of 31-60 years in the year 2020. Erythromycin revealed a decrease in susceptibility from the year 2018 (71.43%) to 2020 (16.22%). A decreased susceptibility of 90% was recorded for levofloxacin in the year 2021. Meropenem revealed a decrease in susceptibility from the year 2018 (85.71%) to 2020 (35.14%). Penicillin susceptibility decreased from 37.5% in 2019 to 27.03% in the year 2020. Clindamycin indicated a 100% susceptibility in the year 2018 which then decreased to 71.88% in 2019 and 56.76% in 2020. Linezolid and vancomycin were found to have uniform susceptibility of 100% throughout the years from 2018 to 2021. An increase in resistance to penicillin and macrolides among S. pneumoniae isolates was observed in the Indian population. Addressing the elevating rates of S. pneumoniae resistance may require pneumococcal conjugate vaccines (PCVs) with expanded serotype coverage and targeted antimicrobial stewardship efforts.

Microbial Ecology of Pecorino Siciliano PDO Cheese Production Systems

Pecorino Siciliano PDO is a semi-hard cheese that is produced in wooden vats using raw sheep’s milk and its associated autochthonous microbial community. In the present study, we evaluated the microbial ecology of the milk, curd and whey from five Pecorino Siciliano PDO-producing farms in Sicily using a combination of metagenomic and microbiological approaches. We present an overview of the species and strain-level diversity of dairy lactococcal and streptococcal isolates using established genotyping tools and compare the lactic acid bacterial populations present in samples from these farms. Whole genome sequences of representative isolates of Lactococcus spp. and Streptococcus thermophilus were elucidated and the genetic diversity of the strains was established through analysis of predicted phage-resistance systems and prophage-associated regions. The analysis revealed farm-specific dairy lactococcal and streptococcal isolates that possess diverse genotypic features including newly described phage-resistance systems.

Group B Streptococcus CRISPR1 Typing of Maternal, Fetal, and Neonatal Infectious Disease Isolates Highlights the Importance of CC1 in In Utero Fetal Death.

We performed a descriptive analysis of group B Streptococcus (GBS) isolates responsible for maternal and fetal infectious diseases from 2004 to 2020 at the University Hospital of Tours, France. This represents 115 isolates, including 35 isolates responsible for early-onset disease (EOD), 48 isolates responsible for late-onset disease (LOD), and 32 isolates from maternal infections. Among the 32 isolates associated with maternal infection, 9 were isolated in the context of chorioamnionitis associated with in utero fetal death. Analysis of neonatal infection distribution over time highlighted the decrease in EOD since the early 2000s, while LOD incidence has remained relatively stable. All GBS isolates were analyzed by sequencing their CRISPR1 locus, which is an efficient way to determine the phylogenetic affiliation of strains, as it correlates with the lineages defined by multilocus sequence typing (MLST). Thus, the CRISPR1 typing method allowed us to assign a clonal complex (CC) to all isolates; among these isolates, CC17 was predominant (60/115, 52%), and the other main CCs, such as CC1 (19/115, 17%), CC10 (9/115, 8%), CC19 (8/115, 7%), and CC23 (15/115, 13%), were also identified. As expected, CC17 isolates (39/48, 81.3%) represented the majority of LOD isolates. Unexpectedly, we found mainly CC1 isolates (6/9) and no CC17 isolates that were responsible for in utero fetal death. Such a result highlights the possibility of a particular role of this CC in in utero infection, and further investigations should be conducted on a larger group of GBS isolated in a context of in utero fetal death. IMPORTANCE Group B Streptococcus is the leading bacterium responsible for maternal and neonatal infections worldwide, also involved in preterm birth, stillbirth, and fetal death. In this study, we determined the clonal complex of all GBS isolates responsible for neonatal diseases (early- and late-onset diseases) and maternal invasive infections, including chorioamnionitis associated with in utero fetal death. All GBS was isolated at the University Hospital of Tours from 2004 to 2020. We described the local group B Streptococcus epidemiology, which confirmed national and international data concerning neonatal disease incidence and clonal complex distribution. Indeed, neonatal diseases are mainly characterized by CC17 isolates, especially in late-onset disease. Interestingly, we identified mainly CC1 isolates responsible for in utero fetal death. CC1 could have a particular role in this context, and such a result should be confirmed on a larger group of GBS isolated from in utero fetal death.

Phenotypic and Molecular Investigation of Streptococcus pneumoniae pneumolysin

The current study aimed to detect the prevalence of Streptococcus pneumoniae by identifying Pneumolysin and determining the gene (ply) using polymerase chain reaction (PCR). The study aimed to highlight the isolation and identification of Streptococcus pneumoniae using morphological, biochemical and Vitek, as well as investigation about pneumolysin phenotypically and molecularly through ply gene and sent the PCR products to sequencing by sanger method. Fifty sputum specimens were collected from patients at AL Salam Hospital, Iben Sina/ Mosul/ Iraq, from August 2021 to March 2022. The isolated bacteria were identified depending on morphology and biochemical properties; Vitek and the ply gene were detected by PCR technique. Five isolates of Streptococcus pneumoniae showed the ability to produce pneumolysin when tested by a double agar layer. When PCR reaction was performed on the Streptococcus pneumoniae pneumolysin gene, the results on gel electrophoresis showed three bands with 238 bp, and the ratio of the presence of the ply gene was 80%. PCR products were then submitted to sequencing by the Sanger method, and the ply sequencing result showed Point mutations that nucleotide and amino acid change with location. Keywords: Streptococcus pneumonia; pneumolysin; ply gene; PCR sequencing.

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.

Serotype distribution and antimicrobial susceptibility profile of invasive group B streptococcal disease-in South Indian population

PurposeInvasive group B Streptococcal disease (iGBS) is an important cause of morbidity and mortality in neonates for which the development of an efficacious vaccine remains a global health imperative. The knowledge about the serotype distribution of iGBS is important component for formulation of Capsular polysaccharide (CPS)-based vaccine. However, there were absolute lack of information on serotype distribution in invasive GBS isolates from Indian subcontinent. Methods This study has assessed the serotype distribution and antimicrobial susceptibility profile of invasive group B streptococcal isolates for a period of 13 years from 2009 to 2022 from a tertiary care Center in South India. A total of 155 iGBS isolates were subjected to serotyping by conventional multiplex PCR for identification of all ten GBS serotype. Antimicrobial susceptibility profile and demographic details were extracted from microbiological records. Results Overall, the most common serotype causing invasive GBS were Ia (29%), V (26%), III (15%), II (12%), VI (6%), VII (5%) and Ib (5%). Serotypes IV, VIII and XI were not detected. Among the early-onset iGBS, the common serotype were Ia (36%), V (27%), and III (8%). In late onset iGBS, Serotype III (44%) was predominant. The common serotype in adults were Serotype V (31%) and III (20%). All the invasive GBS isolates were susceptible for penicillin (100%), but the susceptibility for clindamycin and erythromycin were 72% and 80% respectively. Conclusion The serotype distribution of invasive Group B streptococcal isolates from India suggest that hexavalent group B CPS vaccine will cover only 90% of GBS isolates causing invasive disease among the infants in India. Continued surveillance monitoring for serotype distribution and antimicrobial resistance patterns for iGBS are warranted to make public health interventions.

Time to reconsider antibiotic prophylaxis in women with prolonged rupture of membranes: The trend of Enterobacteriaceae in peripartum infections.

The proportion of neonatal early-onset sepsis (EOS) by gram-negative bacteria has increased. The authors examined bacterial distribution in the amniotic membrane cultures of women with peripartum fever (PPF) and related perinatal outcomes. This retrospective study covered the period 2011 to 2019. The primary outcomes were Enterobacteriaceae-positive birth culture rates in women with PPF and the trend of ampicillin resistance. Maternal and neonatal outcomes were compared between women with group B Streptococcus (GBS) and Enterobacteriaceae-positive isolates. Bacterial distribution was also compared according to rupture of membrane (ROM) duration. Among 621 women with PPF, the positive birth culture rate was 52%. Increasing prevalences of ampicillin-resistant Enterobacteriaceae (81%) were noted. Positive birth cultures were associated with maternal bacteremia (P = 0.017) and neonatal EOS (P = 0.003). Prolonged ROM ≥18 h was associated with increased risk for Enterobacteriaceae-positive cultures, while intrapartum ampicillin and gentamicin were associated with lower risk. Enterobacteriaceae-positive compared with GBS-positive birth cultures were associated with adverse maternal and neonatal outcomes. Positive birth cultures were related to maternal bacteremia and neonatal sepsis. Adverse outcomes were more prevalent among women with Enterobacteriaceae-positive versus GBS-positive birth cultures. Prolonged ROM is a risk factor for Enterobacteriaceae-positive birth cultures among women with PPF. Antibiotic prophylaxis treatment for prolonged ROM should be reconsidered.

Prevalence of the optrA gene among Streptococcus suis isolates from diseased pigs and identification of a novel integrative conjugative element ICESsu988S

Aim of this study was to investigate the prevalence and genetic environment of the oxazolidinone resistance gene optrA in Streptococcus suis (S. suis) isolates from diseased pigs in China. A total of 178 S. suis isolates were screened for the optrA gene by PCR. The phenotypes and genotypes of optrA-positive isolates were investigated by antimicrobial susceptibility testing, core genome Multilocus Sequence Typing (cgMLST), capsular serotypes determination and whole-genome sequencing (WGS). Fifty-one (28.7%) S. suis isolates were positive for optrA. Phylogenetic analysis indicated that the spread of the optrA among S. suis isolates was primarily due to horizontal transfer. Analysis of S. suis serotypes from diseased pigs revealed substantial diversity. The genetic environment of optrA was complex and diverse and could be divided into 12 different types. Interestingly, we identified a novel integrative and conjugative element ICESsu988S, carrying optrA and erm(T) genes. This is to the best of our knowledge the first report of the optrA and erm(T) co-located on an ICE in S. suis. Our results showed a high prevalence of optrA gene in S. suis isolates in China. Further research is needed to evaluate the importance of ICEs, as they horizontally propagate important clinical resistance genes.

Antimicrobial susceptibility testing of invasive isolates of Streptococcus pneumoniae from Canadian patients: the SAVE study, 2011-2020.

To assess the antimicrobial susceptibility of 14 138 invasive Streptococcus pneumoniae isolates collected in Canada from 2011 to 2020. Antimicrobial susceptibility testing was performed using the CLSI M07 broth microdilution reference method. MICs were interpreted using 2022 CLSI M100 breakpoints. In 2020, 90.1% and 98.6% of invasive pneumococci were penicillin-susceptible when MICs were interpreted using CLSI meningitis or oral and non-meningitis breakpoints, respectively; 96.9% (meningitis breakpoint) and 99.5% (non-meningitis breakpoint) of isolates were ceftriaxone-susceptible, and 99.9% were levofloxacin-susceptible. Numerically small, non-temporal, but statistically significant differences (P < 0.05) in the annual percentage of isolates susceptible to four of the 13 agents tested was observed across the 10-year study: chloramphenicol (4.4% difference), trimethoprim-sulfamethoxazole (3.9%), penicillin (non-meningitis breakpoint, 2.7%) and ceftriaxone (meningitis breakpoint, 2.7%; non-meningitis breakpoint, 1.2%). During the same period, annual differences in percent susceptible values for penicillin (meningitis and oral breakpoints) and all other agents did not achieve statistical significance. The percentage of isolates with an MDR phenotype (resistance to ≥3 antimicrobial classes) in 2011 and 2020 (8.5% and 9.4%) was not significantly different (P = 0.109), although there was a significant interim decrease observed between 2011 and 2015 (P < 0.001) followed by a significant increase between 2016 and 2020 (P < 0.001). Statistically significant associations were observed between resistance rates to most antimicrobial agents included in the MDR analysis (penicillin, clarithromycin, clindamycin, doxycycline, trimethoprim/sulfamethoxazole and chloramphenicol) and patient age, specimen source, geographic location in Canada or concurrent resistance to penicillin or clarithromycin, but not biological sex of patients. Given the large isolate collection studied, statistical significance did not necessarily imply clinical or public health significance in some analyses. Invasive pneumococcal isolates collected in Canada from 2011 to 2020 generally exhibited consistent in vitro susceptibility to commonly tested antimicrobial agents.

Co-Existence of Oxazolidinone Resistance Genes cfr(D) and optrA on Two Streptococcus parasuis Isolates from Swine.

This study was performed to investigate the presence and characteristics of the oxazolidinone resistance genes optrA and cfr(D) in Streptococcus parasuis. In total, 36 Streptococcus isolates (30 Streptococcus suis isolates, 6 Streptococcus parasuis isolates) were collected from pig farms in China in 2020-2021, using PCR to determine the presence of optrA and cfr. Then, 2 of the 36 Streptococcus isolates were further processed as follows. Whole-genome sequencing and de novo assembly were employed to analyze the genetic environment of the optrA and cfr(D) genes. Conjugation and inverse PCR were employed to verify the transferability of optrA and cfr(D). The optrA and cfr(D) genes were identified in two S. parasuis strains named SS17 and SS20, respectively. The optrA of the two isolates was located on chromosomes invariably associated with the araC gene and Tn554, which carry the resistance genes erm(A) and ant(9). The two plasmids that carry cfr(D), pSS17 (7550 bp) and pSS20-1 (7550 bp) have 100% nucleotide sequence identity. The cfr(D) was flanked by GMP synthase and IS1202. The findings of this study extend the current knowledge of the genetic background of optrA and cfr(D) and indicate that Tn554 and IS1202 may play an important role in the transmission of optrA and cfr(D), respectively.

Throat Swab Culture Positivity and Antibiotic Resistance Profiles in Children 2-5 Years of Age Suspected of Bacterial Tonsillitis at Hargeisa Group of Hospitals, Somaliland: A Cross-Sectional Study.

Tonsillitis is the third most frequently diagnosed infection in the pediatric age and is associated with significant morbidity and loss of school attendance. Throat swab cultures are useful for the confirmation of children with a clinically suspected tonsillitis. However, Somaliland is one of the underdeveloped countries with a low standard of sanitation and poor health seeking culture. Treatment of tonsillitis with antibiotics is irrational and not empirical. This study determined the bacterial throat swab culture positivity and antibiotic resistance profiles of the bacterial isolates among children 2-5 years of age with suspicion of tonsillitis at Hargeisa Group of Hospital, Somaliland. A cross-sectional study was conducted from March to July 2020. A total of 374 children from 2 to 5 years of age suspicion of tonsillitis was included using a convenient sampling method. Throat swabs were collected, and bacterial isolation and identification were done using standard bacteriological procedures. Antimicrobial susceptibility testing was done using the disk diffusion method. Data on demographic variables and clinical profiles were collected using structured questionnaires. Logistic regression analysis was computed to identify factors associated with bacterial tonsillitis. Overall, 120 (32.1%) (95% CI 27.4-36.8%) of children were positive for bacterial throat cultures. Of these, 23 (19.2%) were mixed bacterial isolates. The most frequent bacterial isolates were beta-hemolytic streptococci 78 (55%), Staphylococcus aureus 42 (29%), and Streptococcus pneumoniae 10 (7%). Isolates revealed 83.3-100% rate of resistance to ampicillin. Beta-hemolytic streptococci isolates were 94.9% resistant to ampicillin. S. aureus was resistant to clarithromycin (38%) while S. pneumoniae isolates were 100% resistant to ampicillin. History of tonsillitis (AOR = 0.12; 95% CI = 0.06-0.21), difficulty in swallowing (AOR = 6.99; 95% CI = 3.56-13.73), and attending schools (AOR = 2.98; 95% CI = 1.64-5.42) were found to be associated with positive throat culture. Resistance to ampicillin and MDR among beta-hemolytic streptococci and other isolates of throat colonizers in children with clinically suspected of bacterial tonsillitis are major concerns in Hargeisa, Somaliland. Therefore, treatments of cases are recommended to be guided by regular culture and antimicrobial susceptibility testing to prevent complications of tonsillitis and associated antibiotic resistance.

CURB-65 and Long-Term Mortality of Community-Acquired Pneumonia: A Retrospective Study on Hospitalized Patients.

Background Community-acquired pneumonia remains a significant factor in global mortality. Several clinical scoring models are used for predicting pneumonia severity and mortality, aiding in the clinical decision relative to the therapeutic approach, including the CURB-65 score. However, currently, no models exist to identify high-risk patients relative to long-term prognosis when recent evidence reveals a significantly higher mortality rate in the first year after community-acquired pneumonia (CAP) hospitalization. Purpose of the study The purpose of this study is to evaluate the application of the CURB-65 scoring model in our population and examine its potential to predict prognosis and subsequent mortality 6 months after hospitalization. Other potential factors influencing mortality during and after hospitalization were characterized: patient demographics, nosocomial infections, readmissions, and identified pathogens. Study design We conducted a retrospective observational study, enrolling 130 patients admitted with a diagnosis of CAP in the department of internal medicine of Centro Hospitalar Universitário Cova da Beira between January and December of 2018. Consultation of electronic medical records was used to calculate the CURB-65 score on admission at the first hospitalization by CAP, categorizing patients into five risk groups. Mortality and readmission were evaluated after 30, 90, and 180 days. Key results High-risk patients (CURB>2) accounted for 96.9% of our study population. Inpatient mortality of 13%, increasing to 21.5% after six months, was similar to previous studies and was correlated to the CURB-65 score on admission. A microbiologic agent was identified in 37% of cases, with 53% isolates of Streptococcus (S.) pneumoniae. Conclusions Identifying high-risk patients is important for more individualized healthcare and management. The CURB-65 score, only validated for ashort-term (30 days) prediction, demonstrates a potential to also predict mortality and rehospitalization in the six-month period after hospitalization, as supported by our findings and previous studies.

Effect of Antibiotic Eye Drops on the Nasal Microbiome in Healthy Subjects-A Pilot Study.

Antibiotic eye drops are frequently used in clinical practice. Due to the anatomical connection via the nasolacrimal duct, it seems possible that they have an influence on the nasal/pharyngeal microbiome. This was investigated by using two different commonly used antibiotic eye drops. 20 subjects were randomized to four groups of five subjects receiving eye drops containing gentamicin, ciprofloxacin, or, as controls, unpreserved povidone or benzalkonium chloride-preserved povidone. Nasal and pharyngeal swabs were performed before and after the instillation period. Swabs were analyzed by Illumina next-generation sequencing (NGS)-based 16S rRNA analysis. Bacterial culture was performed on solid media, and bacterial isolates were identified to the species level by MALDI-TOF MS. Species-dependent antimicrobial susceptibility testing was performed using single isolates and pools of isolates. Bacterial richness in the nose increased numerically from 163 ± 30 to 243 ± 100 OTUs (gentamicin) and from 114 ± 17 to 144 ± 45 OTUs (ciprofloxacin). Phylogenetic diversity index (pd) of different bacterial strains in the nasal microbiome increased from 12.4 ± 1.0 to 16.9 ± 5.6 pd (gentamicin) and from 10.2 ± 1.4 to 11.8 ± 3.1 pd (ciprofloxacin). Unpreserved povidone eye drops resulted in minimal changes in bacterial counts. Preservative-containing povidone eye drops resulted in no change. A minor increase (1-2-fold) in the minimal inhibitory concentration (MIC) was observed in single streptococcal isolates. Antibiotic eye drops could affect the nasal microbiome. After an instillation period of seven days, an increase in the diversity and richness of bacterial strains in the nasal microbiome was observed.

Respiratory culture organism isolation and test characteristics in children with tracheostomies with and without acute respiratory infection.

Among children with tracheostomies, little is known about how respiratory culture results differ between states with and without acute respiratory infections (ARI), or the overall test performance of respiratory cultures. To determine the association of respiratory culture organism isolation with diagnosis of ARI in children with tracheostomies, and assess test characteristics of respiratory cultures in the diagnosis of bacterial ARI (bARI). This single-center, retrospective cohort study included respiratory cultures of children with tracheostomies obtained between 2010 and 2018. The primary predictor was ARI diagnosis code at the time of culture; the primary outcomes were respiratory culture organism isolation and species identified. Generalized estimating equations were used to assess for association between ARI diagnosis and isolation of any organism while controlling for potential confounders and accounting for within-patient clustering. A multinomial logistic regression equation assessed for association with specific species. Test characteristics were calculated using bARI diagnosis as the reference standard. Among 3578 respiratory cultures from 533 children (median 4 cultures/child, interquartile range (IQR): 1-9), 25.9% were obtained during ARI and 17.2% had ≥1 organism. Children with ARI diagnosis had higher odds of organism identification (adjusted odds ratio 1.29, 95% confidence interval [CI] 1.16-1.44). When controlling for covariates, ARI was associated with isolation of Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Streptococcus pyogenes. Test characteristics revealed a 24.3% sensitivity, 85.2% specificity, 36.5% positive predictive value, and 76.3% negative predictive value in screening for bARI. The utility of respiratory culture testing to screen for, diagnose, and direct treatment of ARI in children with tracheostomies is limited.

Streptococcus pneumoniae serotype 19A from carriers and invasive disease: virulence gene profile and pathogenicity in a Galleria mellonella model.

This study aimed to evaluate and compare the presence of genes related to surface proteins between isolates of Streptococcus pneumoniae from healthy carriers (HC) and invasive pneumococcal disease (IPD) with a particular focus on serotype 19A. The presence of these genes was identified by real-time PCR. Subsequently, we employed the Galleria mellonella larval infection model to study their effect on pathogenicity in vivo. The percentage of selected virulence genes was similar between the HC and IPD groups (p > 0.05), and the genes lytA, nanB, pavA, pcpA, phtA, phtB, phtE, rrgA, and sipA were all present in both groups. However, the virulence profile of the isolates differed individually between HC and IPD groups. The highest lethality in G. mellonella was for IPD isolates (p < 0.01), even when the virulence profile was the same as compared to the HC isolates or when the nanA, pspA, pspA-fam1, and pspC genes were not present. The occurrence of the investigated virulence genes was similar between HC and IPD S. pneumoniae serotype 19A groups. However, the IPD isolates showed a higher lethality in the alternative G. mellonella model than the HC isolates, regardless of the virulence gene composition, indicating that other virulence factors may play a decisive role in virulence. Currently, this is the first report using the in vivo G. mellonella model to study the virulence of clinical isolates of S. pneumoniae.

Serotype Distribution and Antimicrobial Resistance of Streptococcus agalactiae Isolates in Nonpregnant Adults with Streptococcal Toxic Shock Syndrome in Japan in 2014 to 2021.

The incidence of streptococcal toxic shock syndrome (STSS) due to group B Streptococcus (GBS) has been increasing annually in Japan and is becoming a serious challenge. Furthermore, in recent years, penicillin- or clindamycin-resistant strains used in treating streptococcal toxic shock syndrome have been reported. However, no report analyzed >100 isolates of group B Streptococcus causing streptococcal toxic shock syndrome. Therefore, we aimed to perform serotyping and antimicrobial susceptibility testing of 268 isolated group B Streptococcus strains from streptococcal toxic shock syndrome cases involving nonpregnant adult patients in Japan between 2014 and 2021. The most prevalent serotype was Ib, followed by serotypes V, III, and Ia. Seven isolates were resistant to penicillin G, and 17.9% (48 isolates) were resistant to clindamycin. Of the penicillin-resistant group B Streptococcus isolates, 71.4% (5 isolates) were clindamycin resistant. In addition, group B Streptococcus strains resistant to penicillin and clindamycin were isolated from patients with streptococcal toxic shock syndrome. Therefore, before these strains become prevalent, introduction of the group B Streptococcus vaccine is essential for disease prevention. IMPORTANCE Group B Streptococcus (GBS) has been increasingly associated with invasive disease in nonpregnant adults. Such infections are responsible for substantial morbidity and mortality, particularly in individuals with underlying chronic conditions. Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multiorgan failure, and high mortality. In this study, we assessed 268 GBS-related STSS cases in nonpregnant adults in Japan between 2014 and 2021. Serotype Ib was the most prevalent, followed by serotypes V, III, and Ia, which were identified in more than 80% of STSS isolates. We found that 48 clindamycin-resistant strains and 7 penicillin G-resistant strains were isolated between 2014 and 2021. We believe that our study makes a significant contribution to the literature because we show that the GBS vaccine, particularly the hexavalent conjugate vaccine, is important to reduce the number of patients with STSS.

Antibiotic resistance pattern, capsular types, and molecular characterization of invasive isolates of Streptococcus pneumoniae in the south of Tunisia from 2012 to 2018

BackgroundStreptococcus pneumoniae remains a leading cause of morbidity and mortality worldwide. In this study, we sought to analyze serotype distributions, antibiotic resistance, and genetic relationships of 106 clinical invasive pneumococcal isolates recovered in Tunisia between 2012 and 2018, prior to the routine use of pneumococcal conjugate vaccines (PCV).MethodsWe used multiplex PCR, the disk diffusion method and/or E-test, and multi-locus sequence typing (MLST).ResultsThe most frequent serotypes were 14 (17%), 19F (14.2%), and 3 (11.3%). Of the 106 S. pneumoniae isolates, 67.9% were penicillin non-susceptible (29.4% were resistant), 45.3% were amoxicillin non-susceptible (17% were resistant), and 16% were cefotaxime non-susceptible. For antibiotics other than β-lactams, resistance rates to erythromycin, tetracycline, cotrimoxazole, and chloramphenicol were 62.3, 33, 22.6, and 4.7%, respectively. Two isolates were non-susceptible to levofloxacin. Among 66 erythromycin-resistant pneumococci, 77.3% exhibited the cMLSB phenotype, and 87.9% carried ermB gene. All tetracycline-resistant strains harbored the tetM gene. The potential coverage by 7-, 10-, and 13-valent pneumococcal conjugate vaccines were 55.7, 57.5, and 81.1%, respectively. A multilocus sequence typing analysis revealed great diversity. Fifty different sequence types (STs) were identified. These STs were assigned to 10 clonal complexes and 32 singletons. The most common STs were 179, 2918, 386, and 3772 – related mainly to 19F, 14, 6B/C, and 19A serotypes, respectively.ConclusionsThis study demonstrated that the majority of the serotypes of invasive pneumococci in the Tunisian population were 14, 19F, and 3. Moreover, we noted a high degree of genetic diversity among invasive S. pneumoniae isolates. The highest proportions of antibiotic non-susceptible isolates were for penicillin, erythromycin, and tetracycline. Further molecular characteristics are required to monitor the genetic variations and to follow the emergence of resistant pneumococci for the post-vaccination era in Tunisia.

Complete Genome Sequences of Streptococcus parauberis Serotype Ia, Ib/Ic, and II Isolates from Diseased Olive Flounder in South Korea.

We report the complete genome sequences of three isolates of Streptococcus parauberis, representing serotypes Ia, Ib/Ic, and II, which were isolated from diseased olive flounder (Paralichthys olivaceus) in South Korea.