Clinical, microbiological, and molecular characterization of pediatric invasive infections by Streptococcus pyogenes in Spain in a context of global outbreak.

In December 2022, an alert was published in the UK and other European countries reporting an unusual increase in the incidence of Streptococcus pyogenes infections. Our aim was to describe the clinical, microbiological, and molecular characteristics of group A Streptococcus invasive infections (iGAS) in children prospectively recruited in Spain (September 2022-March 2023), and compare invasive strains with strains causing mild infections. One hundred thirty isolates of S. pyogenes causing infection (102 iGAS and 28 mild infections) were included in the microbiological study: emm typing, antimicrobial susceptibility testing, and sequencing for core genome multilocus sequence typing (cgMLST), resistome, and virulome analysis. Clinical data were available from 93 cases and 21 controls. Pneumonia was the most frequent clinical syndrome (41/93; 44.1%), followed by deep tissue abscesses (23/93; 24.7%), and osteoarticular infections (11/93; 11.8%). Forty-six of 93 cases (49.5%) required admission to the pediatric intensive care unit. iGAS isolates mainly belonged to emm1 and emm12; emm12 predominated in 2022 but was surpassed by emm1 in 2023. Spread of M1UK sublineage (28/64 M1 isolates) was communicated for the first time in Spain, but it did not replace the still predominant sublineage M1global (36/64). Furthermore, a difference in emm types compared with the mild cases was observed with predominance of emm1, but also important representativeness of emm12 and emm89 isolates. Pneumonia, the most frequent and severe iGAS diagnosed, was associated with the speA gene, while the ssa superantigen was associated with milder cases. iGAS isolates were mainly susceptible to antimicrobials. cgMLST showed five major clusters: ST28-ST1357/emm1, ST36-ST425/emm12, ST242/emm12.37, ST39/emm4, and ST101-ST1295/emm89 isolates. IMPORTANCE: Group A Streptococcus (GAS) is a common bacterial pathogen in the pediatric population. In the last months of 2022, an unusual increase in GAS infections was detected in various countries. Certain strains were overrepresented, although the cause of this raise is not clear. In Spain, a significant increase in mild and severe cases was also observed; this study evaluates the clinical characteristics and the strains involved in both scenarios. Our study showed that the increase in incidence did not correlate with an increase in resistance or with an emm types shift. However, there seemed to be a rise in severity, partly related to a greater rate of pneumonia cases. These findings suggest a general increase in iGAS that highlights the need for surveillance. The introduction of whole genome sequencing in the diagnosis and surveillance of iGAS may improve the understanding of antibiotic resistance, virulence, and clones, facilitating its control and personalized treatment.

Dynamics of respiratory viruses other than SARS-CoV-2 during the COVID-19 pandemic in Madrid, Spain.

The COVID-19 pandemic and the implemented control measures have impacted the circulation of respiratory-transmitted pathogens. In this report, we present data from a retrospective study that included 17,883 specimens conducted between 2018 and 2022 in our facility, describing the dynamics of circulation of the main respiratory viruses. We observed a significant decrease in all viral detections (other than SARS-CoV-2) starting from March 2020. However, rhinovirus maintained comparable levels to the pre-pandemic period. Additionally, influenza viruses were not detected during the 2020-2021 season, and respiratory syncytial virus (RSV) exhibited a shift in its seasonality, with an epidemic peak occurring in the summer of 2021.

Comprehensive analysis of current epidemiology, clinical features and prognostic factors of puerperal endometritis: A retrospective cohort analysis.

Background: Puerperal endometritis has not been recently investigated. We aimed to describe the current dimension of the endometritis in the context of other causes of puerperal fever and investigate the microbiology and need for curettage in these patients. Methods: A retrospective cohort study was conducted based on a prospectively maintained database of patients with puerperal fever, (2014-2020) in which cases fulfilling criteria for endometritis were selected for further analysis. Description of clinical and microbiological features was performed and determination of the factors related with puerperal curettage requirement were studied using univariate and multivariate analysis through binary logistic regression. Results: From 428 patients with puerperal fever, endometritis was the main cause of puerperal fever (233 patients, 52.7 %). Curettage was required in 96 of them (41.2 %). Culture of endometrial samples were performed in 62 (64.5 %), of which 32 (51.6 %) yielded bacterial growth. Escherichia coli was the most common microorganism in curettage cultures (46.9 %). Multivariate analysis identified the following predictive factors for curettage: the presence of pattern compatible with retained products of conception (RPOC) in transvaginal ultrasonography (odds ratio [OR]: 17.6 [95 % confidence interval [CI]: 8.4-36.6]; P-value < 0.0001), fever during the first 14 days after delivery (OR:5.1; [95 % CI: 1.57-16.5]; P-value 0.007), abdominal pain (OR: 2.9; [95 % CI: 1.36-6.1]; P-value 0.012) and malodorous lochia (OR:3.5; [95 % CI: 1.25-9.9]; P-value 0.017). Scheduled cesarean delivery was protective (OR: 0.11 [95 % CI 0.01-1.2]; P-value 0.08). Conclusions: Endometritis is still the main cause of puerperal fever. Women requiring curettage typically presented with abdominal pain and foul-smelling lochia, an ultrasound image compatible with RPOC and fever in the first 14 days postpartum. Curettage culture is useful for the microbiological affiliation mostly yielding gram-negative enteric flora.

A prospective study to identify preoperative serum parameters for spinal implant infection detected by sonication fluid culture.

PURPOSE: Low-virulent microorganisms identified on pedicle screws by sonication fluid culture (SFC) are an important cause of implant loosening. While sonication of explanted material improves the detection rate, the risk of contamination exists and no standardized diagnostic criteria for chronic low-grade spinal implant-related infection (CLGSII) are stablished. Besides, the role of serum C-reactive protein (CRP) and procalcitonin (PCT) in CLGSII has not been adequately investigated. METHODS: Blood samples were collected prior to implant removal. To increase sensitivity, the explanted screws were sonicated and processed separately. Patients exhibiting at least one positive SFC were classified in the infection group (loose criteria). To increase specificity, the strict criteria only considered multiple positive SFC (≥ 3 implants and/or ≥ 50% of explanted devices) as meaningful for CLGSII. Factors which might promote implant infection were also recorded. RESULTS: Thirty-six patients and 200 screws were included. Among them, 18 (50%) patients had any positive SFCs (loose criteria), whereas 11 (31%) patients fulfilled the strict criteria for CLGSII. Higher serum protein level was the most accurate marker for the preoperative detection of CLGSSI, exhibiting an area under the curve of 0.702 (loose criteria) and 0.819 (strict criteria) for the diagnosis of CLGSII. CRP only exhibited a modest accuracy, whereas PCT was not a reliable biomarker. Patient history (spinal trauma, ICU hospitalization and/or previous wound-related complications) increased the likelihood of CLGSII. CONCLUSION: Markers of systemic inflammation (serum protein level) and patient history should be employed to stratify preoperative risk of CLGSII and decide the best treatment strategy.

Genomic Analysis of Ceftazidime/Avibactam-Resistant GES-Producing Sequence Type 235 Pseudomonas aeruginosa Isolates.

The emergence of ceftazidime/avibactam (CZA) resistance among Guiana extended-spectrum ß-lactamase (GES)-producing Pseudomonas aeruginosa isolates has rarely been described. Herein, we analyze the phenotypic and genomic characterization of CZA resistance in different GES-producing P. aeruginosa isolates that emerged in our institution. A subset of nine CZA-resistant P. aeruginosa isolates was analyzed and compared with thirteen CZA-susceptible isolates by whole-genome sequencing (WGS). All CZA-resistant isolates belonged to the ST235 clone and O11 serotype. A variety of GES enzymes were detected: GES-20 (55.6%, 5/9), GES-5 (22.2%, 2/9), GES-1 (11.1%, 1/9), and GES-7 (11.1%, 1/9). WGS revealed the presence of two mutations within the blaGES-20 gene comprising two single-nucleotide substitutions, which caused aspartic acid/serine and leucine/premature stop codon amino acid changes at positions 165 (D165S) and 237 (L237X), respectively. No major differences in the mutational resistome (AmpC, OprD porin, and MexAB-OprM efflux pump-encoding genes) were found among CZA-resistant and CZA-susceptible isolates. None of the mutations that have been previously demonstrated to cause CZA resistance were observed. Different mutations within the blaGES-20 gene were documented in CZA-resistant GES-producing P. aeruginosa isolates belonging to the ST235 clone in our institution. Although further analysis should be performed, according to our results, other resistance mechanisms might be involved in CZA resistance.

Reduction of Instrumentation-Related Spine Surgical Site Infections After Optimization of Surgical Techniques. A Single Center Retrospective Analysis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Although surgical risk factors for developing spine surgical site infections (S-SSI) have been identified, the impact of such knowledge in its prevention has not been demonstrated. METHODS: We evaluated in 500 patients undergoing spine surgery between 2011 and 2019 at Hospital 12 de Octubre the changes in S-SSI rates over time. Surgical variables independently related to S-SSI were analyzed by univariate and multivariate analysis using binary logistic regression models. A case-control sub-analysis (1:4), matched by the surgical variables identified in the overall cohort was also performed. RESULTS: Twenty cases of S-SSI were identified (4%), with a significant decrease in the incidence rate across consecutive time periods (6.6% [2011-2014] vs .86% [2015-2019]; P-value <.0001)). Multivariate analysis identified arthrodesis involving sacral levels (odds ratio [OR]: 2.57; 95% confidence interval [95%CI]: 1.02-6.47; P-value = .044) and instrumentation over 4-8 vertebrae (OR: 2.82; 95%CI: 1.1-7.1; P-value = .027) as independent risk factors for S-SSI. The reduction in the incidence of S-SSI concurred temporally with a reduction in instrumentations involving 4-8 vertebrae (55% vs 21.8%; P-value <.0001) and sacral vertebrae (46.9% vs 24.6%; P-value <.0001) across both periods. The case-control analysis matched by these surgical variables failed to identify other factors independently related to the occurrence of S-SSI. CONCLUSIONS: Spinal fusion of more than 4 levels and the inclusion of sacral levels were independently related to the risk of S-SSI. Optimization of surgical techniques by reducing these two types of instrumentation could significantly reduce S-SSI rates.

Experience with leflunomide as treatment and as secondary prophylaxis for cytomegalovirus infection in lung transplant recipients: A case series and review of the literature.

BACKGROUND: Data concerning the use of leflunomide-a drug approved for rheumatoid arthritis with in vitro anticytomegalovirus (CMV) activity-in lung transplant (LT) recipients are scarce. AIMS: To report the use of leflunomide in LT recipients diagnosed with CMV infection/disease. MATERIAL AND METHODS: We performed a single-center retrospective study including LT recipients who received leflunomide for CMV infection or as secondary prophylaxis after viremia clearance. We also conducted a full systematic PubMed search until June 30, 2017. RESULTS: We identified 5 LT recipients in our center plus 7 patients reported in the literature. All patients had previously received ganciclovir (GCV) and foscarnet (FOS), with drug-induced adverse effects described in 6 recipients (50%). Antiviral resistance mutations were observed in 8 patients (66.7%). Leflunomide was prescribed for CMV infection in 9 of 12 patients (75%) and as secondary prophylaxis in 3 patients (25%). Initial decrease of CMV viremia after starting leflunomide was observed in 7 of 9 recipients (77.7%), although this response was only transient in 2 patients. Long-term suppression of CMV viremia was reported in 7 of 12 patients (58.3%). In 3 recipients (25%), leflunomide was discontinued due to adverse effects. DISCUSSION: Our study has some limitations, such as the small number of patients included, its retrospective nature, and absence of leflunomide drug monitoring in serum. Notwithstanding, in our experience, leflunomide proved to be particularly effective as an anti-CMV secondary prophylaxis treatment and for clearing low-grade viremia. Moreover, leflunomide combined with a short course of GCV or intravitreal FOS also proved to be very effective in some patients. CONCLUSION: Leflunomide, alone or in combination, could be an effective treatment in selected LT recipients with GCV-resistant CMV infection and as secondary prophylaxis. Further studies are necessary.

Molecular epidemiology of carbapenemase-producing Enterobacteriaceae infection/colonisation in a hospital in Madrid. / Epidemiología molecular de las infecciones/colonizaciones por enterobacterias productoras de carbapenemasas en un hospital de Madrid.

INTRODUCTION: A description is presented on the molecular epidemiology of carbapenemase-producing enterobacteriaceae infection in a tertiary hospital. MATERIAL AND METHODS: A study was made on all the carbapenemase-producing enterobacteriaceae isolations obtained between February 2015 and March 2016 in the Hospital Universitario 12 de Octubre (Madrid). Phenotypic and molecular methods were used. RESULTS: A total of 7 bacterial species were identified, with the majority being Klebsiella pneumoniae (K. pneumoniae) (78.9%) and Enterobacter cloacae (E. cloacae) (16.4%). The resistance of K. pneumoniae and E. cloacae for carbapenems was 88.7 and 88.6% for ertapenem, 21.4 and 54.3% for imipenem, and 20.8 and 34.3% for meropenem, respectively. The most frequent carbapenemase type was OXA-48 (91.1%) and VIM (71.4%) in E. cloacae. A total of 9K. pneumoniae clonal types were identified, including a majority pertaining to the sequence type ST11. In E. cloacae, 16 clonal types were identified. CONCLUSIONS: The current increase in carbapenemase-producing enterobacteriaceae is mainly due to the spread of OXA-48-producing K. pneumoniae.

Pathogenic Characteristics of Staphylococcus aureus Endovascular Infection Isolates from Different Clonal Complexes.

Staphylococcus aureus is a major cause of bacteremia and, even with appropriate clinical management, causes high morbidity, and mortality due to its involvement in endovascular complications and metastatic infections. Through different pathogenic in vivo and in vitro models we investigated the behavior of S. aureus most relevant clonal complexes (CCs) causing endovascular complications. We analyzed 14 S. aureus strains representing CC5, CC8, CC15, CC30, and CC45 that caused endovascular complications, including methicillin susceptible and resistant isolates and strains with different functionality of the agr global regulator. Their adherence to collagen, interaction with the endothelium, resistance to immune attack, capacity to form biofilm and virulence in the Galleria mellonella model were analyzed. CC30 and CC45 showed greater adhesion to collagen and CC8 showed a trend towards higher rate of intracellular persistence in endothelial cells. All CCs exhibited similar tolerance to neutrophil antimicrobial peptide hNP-1 and were capable of forming biofilms under static conditions. The virulence assay in the G. mellonella model demonstrated that CC15 and CC30 were the most and least virulent, respectively. The analysis of the genomic sequences of the most relevant virulence genes identified some CC15 specific gene patterns (absence of enterotoxins and sak gene) and variants (mainly in leucocidins and proteases), but did not reveal any gene or variant that could be responsible for the increased virulence detected for CC15 strains. Even though all the CCs were capable of causing endovascular complications, our results showed that different CCs are likely to produce these complications through different mechanisms which, if confirmed in more sophisticated models, would indicate the need to more specific management and therapeutic approaches.

Influence of molecular characteristics in the prognosis of methicillin-resistant Staphylococcus aureus prosthetic joint infections: beyond the species and the antibiogram.

We have explored the relationship of phenotypic (antibiogram, ß-haemolysis, agr functionality, biofilm formation) and genotypic characteristics on the prognosis of 18 cases of methicillin-resistant S. aureus prosthetic joint infection (2005-2015). All isolates belonged to CC5, and had agr type II. This pilot study suggests that phage-borne genes belonging to the immune evasion cluster (chp, sak and scn) were more frequent among episodes with treatment failure (80.0 vs. 37.5%).

Cytomegalovirus Genotype Distribution Among Congenitally and Postnatally Infected Patients: Association of Particular Glycoprotein (g)B and gN Types With Symptomatic Disease.

Background. Human cytomegalovirus is a leading cause of congenital infection, and there are limited data on prognosis markers in disease development. We aimed to study 3 virology targets (glycoprotein [g]B, gN, and UL144) to assess their correlation with congenital infection and various organ system involvement. Methods. Forty-eight congenital cases and 58 postnatally infected children were included (2003-2014). Genotyping for the 3 targets and distribution among the cohorts were investigated, and the relationship between the gB, gN, and UL144 types with clinical manifestations in congenital infection was also studied. Results. All of the genotypes were similarly represented among cohorts, and the most prevalent were the UL144B, gB1, and gN1 genotypes. The gB2 genotype was associated with abnormal image findings by ultrasound and/or magnetic resonance in congenital infection (odds ratio [OR], 6.2; 95% confidence interval [CI], 1.1-34.3; P = .036); the gN1 genotype was associated with an elevated risk of developing neurological disorders (OR, 7.0; 95% CI, 1.1-45.9; P = .043). Both gN1 and gB2 were independent factors for symptomatic infection. Statistical analyses showed no association between any UL144 genotype and disease severity. Conclusions. All of the genotypes can be involved in congenital infection, although the gB2 and gN1 genotypes might be associated with a more serious illness.

Molecular epidemiology of carbapenemase-producing Klebsiella pneumoniae in a hospital in Madrid: Successful establishment of an OXA-48 ST11 clone.

Here we report a retrospective clinical and molecular study conducted in a tertiary care facility in southern Madrid, Spain, from January 2009 to February 2014 to investigate the epidemiology of carbapenemase-producing Klebsiella pneumoniae (CPKp). Carbapenemase genes were identified in 97 non-duplicate K. pneumoniae isolates, including 59 harbouring blaOXA-48, 37 harbouring blaVIM-1 and 1 harbouring blaKPC-2. Pulsed-field gel electrophoresis (PFGE) analysis verified the presence of 20 different clonal types, whilst multilocus sequence typing (MLST) assigned the isolates to eight sequence types (STs). A gradual increase was noted in the number of CPKp isolated, ranging from 0.8% in 2009 to 4.3% in 2013. A large outbreak was also identified, initiated in 2013 owing to a blaOXA-48 and blaCTX-M-15 co-producing ST11 clone and involving a total of 44 patients. Whole-genome sequencing was used to characterise the resistome of a representative isolate from this outbreak. Bioinformatics analysis revealed the presence of 121 genes related to antibiotic and antiseptic resistance, mutations in the ompk35 and ompk36 genes, and the presence of the blaOXA-48 gene on a 62 811bp IncL/M-type plasmid as part of a Tn1999.2 composite transposon. These results portray the increasing trend in carbapenemase-producing isolates in this hospital and highlight the successful establishment of a blaOXA-48 and blaCTX-M-15 co-producing ST11 clone that has led to the displacement of previous circulating clones.

Usefulness of endoluminal catheter colonization surveillance cultures to reduce catheter-related bloodstream infections in hemodialysis.

BACKGROUND: To evaluate the use of surveillance cultures (SCs) to prevent catheter-related bloodstream infections (CRBSIs) in asymptomatic hemodialysis (HD) patients. METHODS: In 2011-2012, we conducted a prospective study of HD patients with tunneled cuffed central venous catheters (TCCs). Colonization of the catheter lumen was assessed every 15 days by inoculating ~5 mL endoluminal blood into aerobic culture bottles. Individual patients were triaged based on SC results: group 1 (negative); group 2 (coagulase-negative Staphylococcus [CoNS] with time-to-positivity (TTP) >14 hours); group 3 (CoNS with TTP ≤14 hours); and group 4 (any microorganism other than CoNS and any TTP). RESULTS: We studied 104 patients (129 TCCs). Median follow-up was 262.5 days (interquartile range [IR], 135.0-365.0). A total of 1,734 SCs were collected (median, 18 per patient; IR, 10.0-24.0), of which 1,634 (94.2%) were negative (group 1) and 100 (5.8%) were positive (group 2: 79; group 3: 12, group 4: 9). In groups 2 and 3, 19 TCCs required antibiotic lock therapy (ALT). In group 4, all patients received intravenous therapy and ALT. Under this protocol, there were 0.27 episodes of CRBSI per 1,000 catheter days compared with 1.65 (P < .001) prior to its implementation. CONCLUSION: SCs based on easily accessible samples proved useful in triaging HD patients at a high risk of infection.

Draft Whole-Genome Sequence of OXA-48-Producing Multidrug-Resistant Klebsiella pneumoniae KP_ST11_OXA-48.

We present the draft genome sequence of a blood culture isolate of OXA-48-producing Klebsiella pneumoniae (sequence type 11 [ST11]) obtained in the course of a hospital outbreak in Spain. Sequence analysis showed 121 genes related to antibiotic and antiseptic resistance, including blaOXA-48, which was located in an IncL/M plasmid.

Multiclonal spread of VIM-1-producing Enterobacter cloacae isolates associated with In624 and In488 integrons located in an IncHI2 plasmid.

Over a 6-year period (2007-2012), the emergence of Enterobacter cloacae isolates resistant to ß-lactams and with reduced susceptibility to carbapenems was observed in Hospital Universitario 12 de Octubre (Madrid, Spain). To determine the possible role of metallo-ß-lactamases (MBLs) in the resistance profile of these isolates, a molecular and clinical epidemiological study was performed, including determination of patients' clinical characteristics, genetic diversity of strains, resistance mechanisms to carbapenems, and the genetic environment of VIM-1. A total of 73 E. cloacae isolates showed resistance to extended-spectrum cephalosporins and reduced susceptibility to at least one carbapenem during 2007-2012. PCR amplification revealed the presence of bla(VIM-1) gene in 37 isolates, bla(VIM-2) in 1 isolate and bla(KPC) in 5 isolates. Molecular typing showed high clonal diversity of E. cloacae isolates carrying bla(VIM-1). The genetic environment of bla(VIM-1) was investigated and two integron structures were found: intI-bla(VIM-1)-aacA4-dfrB1-aadA1-catB2-qacEΔ1/sul1 (In624); and intI-bla(VIM-1)-aacA4-aadA1-qacEΔ1/sul1 (In488). Isolates belonging to three clones (A, F and G) harboured different types of integron (In624 or In488) despite belonging to the same clone. Conjugal experiments showed an association with a conjugative plasmid of ca. 300 kb belonging to IncHI2 group, which is common in Spanish hospitals, suggesting that the widespread dissemination of bla(VIM-1) may be due to horizontal transfer of mobile genetic determinants rather than the result of spreading of a few clones. These results have implications for infection control programmes in the hospital.