Incidence of invasive infections with Group B streptococcus in adults in Norway 1996-2019: a nationwide registry-based case-control study.

PURPOSE: Group B streptococcus (GBS) colonizes the gastrointestinal and vaginal mucosa in healthy adults, but has also become an increasing cause of invasive infection. The aims of this study were to describe the incidence and factors associated with the occurrence of invasive GBS disease in adults in Norway. METHODS: We performed a nationwide retrospective case-control study of invasive GBS infections during 1996-2019, with two control groups; invasive Group A streptococcal disease (GAS) to control for changes in surveillance and diagnostics, and a second representing the general population. RESULTS: A total of 3710 GBS episodes were identified. The age-standardized incidence rate increased steadily from 1.10 (95% CI 0.80-1.50) in 1996 to 6.70 (95% CI 5.90-7.50) per 100,000 person-years in 2019. The incidence rate had an average annual increase of 6.44% (95% CI 5.12-7.78). Incidence rates of GAS varied considerably, and there was no evidence of a consistent change over the study period. GBS incidence was highest among adults > 60 years of age. Cardiovascular disease, cancer, and diabetes were the most common comorbid conditions. There was a shift in the distribution of capsular serotypes from three dominant types to more equal distribution among the six most common serotypes. CONCLUSIONS: The incidence of invasive GBS disease in adults increased significantly from 1996 to 2019. The increasing age of the population with accompanying underlying comorbid conditions might contribute to the increasing burden of invasive GBS disease. Interestingly, type 1 diabetes was also associated with the occurrence of invasive GBS disease.

Coding practice for sepsis 2008-21. / Kodepraksis ved sepsis 2008­21.

Background: Sepsis has a high incidence and mortality rate. Accurate data are needed for health service planning and for research, and there is a need to identify coding practices in Norway. Material and method: All patients over 17 years of age who had been admitted to Norwegian hospitals with sepsis in the period 2008-21 were identified using diagnostic codes for infection plus organ failure, and specific codes for sepsis, from the Norwegian Patient Registry. Results: There were 317 705 admissions with diagnostic codes for sepsis, of which 210 391 (66.2 %) were sepsis with a known focus, 77 627 (24.4 %) were of unknown focus and 29 687 (9.3 %) were codes for both a known and unknown focus. The percentage of sepsis episodes coded with a known focus varied between the health regions. The highest percentage was in the Western Norway Regional Health Authority (72.1 %, 95 % confidence interval (CI): 71.8 to 72.5), and the lowest was in the Central Norway Regional Health Authority (59.2 %, 95 %, CI 58.7 to 59.7). The use of codes with a known focus increased each year on average by 3.2 % (95 % CI 2.7 to 3.6, from 47.5 % in 2008 to 82.3 % in 2021), while the use of codes with an unknown focus decreased by 2.3 % (95 % CI -2.7 to -1.9) from 37.8 % in 2008 to 13.0 % in 2021. Known and unknown focus combined also decreased by 0.9 % per year on average (95 % CI -1.0 to -0.8) from 14.3 % in 2008 to 4.1 % in 2021. Interpretation: The coding of sepsis in Norwegian hospitals has become more uniform.

Epidemiological and clinical characteristics of immunocompromised patients infected with Pneumocystis jirovecii in a twelve-year retrospective study from Norway.

BACKGROUND: Pneumocystis pneumonia (PCP) severely menaces modern chemotherapy and immunosuppression. Detailed description of the epidemiology of Pneumocystis jirovecii today is needed to identify candidates for PCP-prophylaxis. METHODS: We performed a 12-year retrospective study of patients with P. jirovecii detected by polymerase chain reaction in Central Norway. In total, 297 patients were included. Comprehensive biological, clinical and epidemiological data were abstracted from patients' medical records. Regional incidence rates and testing trends were also assessed. RESULTS: From 2007 to 2017 we found a 3.3-fold increase in testing for P. jirovecii accompanied by a 1.8-fold increase in positive results. Simultaneously, regional incidence rates doubled from 5.0 cases per 100,000 person years to 10.8. A majority of the study population had predisposing conditions other than human immunodeficiency virus (HIV). Hematological (36.0%) and solid cancers (25.3%) dominated. Preceding corticosteroids were a common denominator for 72.1%. Most patients (74.4%) presented with at least two cardinal symptoms; cough, dyspnea or fever. Main clinical findings were hypoxia, cytopenias and radiological features consistent with PCP. A total of 88 (29.6%) patients required intensive care and 121 (40.7%) suffered at least one complication. In-hospital mortality was 21.5%. Three patients (1.0%) had received prophylaxis. CONCLUSIONS: P. jirovecii is re-emerging; likely due to increasing immunosuppressants use. This opportunistic pathogen threatens the life of heterogenous non-HIV immunosuppressed populations currently at growth. Corticosteroids seem to be a major risk factor. A strategy to increase prophylaxis is called for.

Prelabor rupture of membranes and the association with cerebral palsy in term born children: a national registry-based cohort study.

BACKGROUND: Guidelines regarding management of prelabor rupture of membranes (PROM) at term vary between immediate induction and expectant management. A long interval between PROM and delivery increases the risk for perinatal infections. Severe perinatal infections are associated with excess risk for cerebral palsy (CP) and perinatal death. We investigated if increasing intervals between PROM and delivery were associated with perinatal death or CP. METHODS: Eligible to participate in this population-based cohort-study were term born singletons without congenital malformations born in Norway during 1999-2009. Data was retrieved from the Medical Birth Registry of Norway (MBRN) and the Cerebral Palsy Register of Norway. In line with the registration in the MBRN, intervals between PROM and delivery of more than 24 h was defined as 'prolonged' and intervals between 12 and 24 h as 'intermediate'. Outcomes were stillbirth, death during delivery, neonatal mortality and CP. Logistic regression was used to calculate odds ratio (OR) with 95% confidence intervals (CI) for adverse outcomes in children born after prolonged and intermediate intervals, compared with a reference group comprising all children born less than 12 h after PROM or without PROM. RESULTS: Among 559,972 births, 34,759 children were born after intermediate and 30,332 were born after prolonged intervals. There was no association between increasing intervals and death during delivery or in the neonatal period, while the prevalence of stillbirths decreased with increasing intervals. Among children born after intermediate intervals 38 (0.11%) had CP, while among those born after prolonged intervals 46 (0.15%) had CP. Compared with the reference group, the OR for CP was 1.16 (CI; 0.83 to 1.61) after intermediate and 1.61 (CI; 1.19 to 2.18) after prolonged intervals. Adjusting for antenatal factors did not affect these associations. Among children with CP the proportion with diffuse cortical injury and basal ganglia pathology on cerebral MRI, consistent with hypoxic-ischemic injuries, increased with increasing intervals. CONCLUSION: Intervals between PROM and delivery of more than 24 h were associated with CP, but not with neonatal mortality or death during delivery. The inverse association with stillbirth is probably due to reverse causality.

Investigation of an outbreak caused by antibiotic-susceptible Klebsiella oxytoca in a neonatal intensive care unit in Norway.

AIM: Klebsiella spp. have been stated to be the most frequent cause of neonatal intensive care unit (NICU) outbreaks. We report an outbreak of Klebsiella oxytoca in a NICU at a tertiary care hospital in Norway between April 2016 and April 2017. This study describes the outbreak, infection control measures undertaken and the molecular methods developed. METHODS: The outbreak prompted detailed epidemiological and microbial investigations, where whole-genome sequencing (WGS) was particularly useful for both genotyping and development of two new K. oxytoca-specific real-time PCR assays. Routine screening of patients, as well as sampling from numerous environmental sites, was performed during the outbreak. A bundle of infection control measures was instigated to control the outbreak, among them strict cohort isolation. RESULTS: Five neonates had symptomatic infection, and 17 were found to be asymptomatically colonised. Infections varied in severity from conjunctivitis to a fatal case of pneumonia. A source of the outbreak could not be determined. CONCLUSION: This report describes K. oxytoca as a significant pathogen in a NICU outbreak setting and highlights the importance of developing appropriate microbiological screening methods and implementing strict infection control measures to control the outbreak in a setting where the source could not be identified.

Stratification by interferon-γ release assay level predicts risk of incident TB.

INTRODUCTION: Targeted testing and treatment of latent TB infection (LTBI) are priorities on the global health agenda, but LTBI management remains challenging. We aimed to evaluate the prognostic value of the QuantiFERON TB-Gold (QFT) test for incident TB, focusing on the interferon (IFN)-γ level, when applied in routine practice in a low TB incidence setting. METHODS: In this large population-based prospective cohort, we linked QFT results in Norway (1 January 2009-30 June 2014) with national registry data (Norwegian Surveillance System for Infectious Diseases, Norwegian Prescription Database, Norwegian Patient Registry and Statistics Norway) to assess the prognostic value of QFT for incident TB. Participants were followed until 30 June 2016. We used restricted cubic splines to model non-linear relationships between IFN-γ levels and TB, and applied these findings to a competing risk model. RESULTS: The prospective analyses included 50 389 QFT results from 44 875 individuals, of whom 257 developed TB. Overall, 22% (n=9878) of QFT results were positive. TB risk increased with the IFN-γ level until a plateau level, above which further increase was not associated with additional prognostic information. The HRs for TB were 8.8 (95% CI 4.7 to 16.5), 19.2 (95% CI 11.6 to 31.6) and 31.3 (95% CI 19.8 to 49.5) times higher with IFN-γ levels of 0.35 to <1.00, 1.00 to <4.00 and >4.00 IU/mL, respectively, compared with negative tests (<0.35 IU/mL). CONCLUSIONS: Consistently, QFT demonstrates increased risk of incident TB with rising IFN-γ concentrations, indicating that IFN-γ levels may be used to guide targeted treatment of LTBI.

Prevalence of Sexually Transmitted Infections among Married Women in Rural Nepal.

Introduction: We have previously determined the prevalence of human papillomavirus (HPV) infection among women in rural Nepal. In the current study, we also wanted to examine the prevalence of and risk factors for other sexually transmitted infections (STIs) in the same population. Methods: Population-based study of nonpregnant women ≥ 15 years who were married or had a history of marriage in the past, residing in five rural villages in Nepal. Data on sociodemographic characteristics, reproductive history, and genitourinary symptoms were collected, and a gynecological examination was conducted. Cervical samples were analyzed by real-time PCR for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis and HPV, and a serum sample was analyzed for syphilis, hepatitis B virus (HBV) and HIV infection by serology. Results: Of 2416 eligible women, 62% participated. Trichomoniasis, Chlamydia trachomatis infection, HPV and HBV infection, and syphilis were detected in 5.4%, 0.8%, 14.3%, 0.3%, and 0.2% of the women. None had gonorrhea or HIV infection. Of those with genitourinary symptoms, 6.3% had a curable STI. Vaginal discharge classified as abnormal by gynecological examination, but not self-reported discharge, was significantly associated with laboratory diagnosis of a curable STI. Risk factors for trichomoniasis were reproductive age and high cast/ethnicity. Due to low prevalence, risk factors for other STIs could not be disclosed. Conclusion: We observed high prevalence of HPV infection followed by trichomoniasis, while other STIs were rare among women in rural Nepal. There was no association between genitourinary symptoms and laboratory-confirmed STIs.

Community-Based Health Education has Positive Influence on the Attitude to Cervical Cancer Screening among Women in Rural Nepal.

The main purpose of this study was to assess the knowledge of cervical cancer among women in rural Nepal and explore the feasibility and impact of a community-based awareness program on cervical cancer. Community-based educational meetings on cervical cancer and its prevention were conducted among women's groups in rural Nepal. Through a questionnaire, the women's baseline knowledge of risk factors, symptoms, and perceived risk of cervical cancer were identified. The willingness to participate in cervical cancer screening was compared before and after the educational meeting. The meetings were followed by a cervical cancer screening program. Among the 122 participants at the educational meeting, only 6 % had heard of cervical cancer. Their baseline knowledge of risk factors and symptoms was poor. The proportion of women willing to participate in cervical screening increased from 15.6 to 100 % after attending the educational meeting. All the study subjects participated in the screening program. Additionally, the study participants recruited a further 222 of their peers for screening. Poor knowledge of cervical cancer among women in rural Nepal highlights the urgency of public awareness programs for cervical cancer at a national level. A community-based awareness program can change women's attitude to cervical screening, and women's groups can play a major role in promoting participation in cervical cancer screening programs.

Insights from a decade of surveillance: Molecular epidemiology of methicillin-resistant Staphylococcus aureus in Norway from 2008 to 2017.

AIM: Norway has a low prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and reporting of all MRSA cases has been mandatory, including infections and carriage, since 1995 and 2005 accordingly. This provides a unique window to study the spread of MRSA in Norway over time. The aim of this study was to analyze the nationwide trends in the molecular epidemiology of MRSA in Norway over a period of 10 years. METHODS: Clinical and epidemiological data as well as bacterial genotype (spa-type and PVL) were analyzed for all reported MRSA cases in Norway in the period 2008-2017. RESULTS: During the study period, there were 15,200 MRSA cases reported in Norway, from 14,386 patients. The notification rate per 100,000 population increased by 15% annually, rising from 14.2 in 2007 to 48.6 in 2017. This increase was primarily driven by MRSA carriage and community-associated MRSA cases. The incidence of invasive infections remained stable and low, at less than 0.5. The incidence of healthcare-associated MRSA showed an increasing trend, while the number of outbreak-related cases, particularly those associated with nursing homes, decreased. Overall, there were significantly more MRSA infections in males than females. Interestingly, there was a significantly higher prevalence of MRSA infections in female young adolescents compared to males. spa-typing revealed a very heterogeneous MRSA population (D = 0.97), predominantly impacted by international travel and migration patterns, and less by domestic spread in the community. CONCLUSIONS: This study highlights that Norway, while still classified as a low-prevalence country, has experienced a significant increase in the incidence of MRSA between 2008 and 2017, which can predominantly be attributed to CA-MRSA and MRSA carriage.

Predicting In-Hospital Death from Derived EHR Trajectory Features.

Medical histories of patients can predict a patient's immediate future. While most studies propose to predict survival from vital signs and hospital tests within one episode of care, we carried out selective feature engineering from longitudinal medical records in this study to develop a dataset with derived features. We thereafter trained multiple machine learning models for the binary prediction of whether an episode of care will culminate in death among patients suspected of bloodstream infections. The machine learning classifier performance is evaluated and compared and the feature importance impacting the model output is explored. The extreme gradient boosting model achieved the best performance for predicting death in the next hospital episode with an accuracy of 92%. Age at the time of the first visit, length of history, and information related to recent episodes were the most critical features.

Enteroaggregative Escherichia coli in mid-Norway: A prospective, case control study.

BACKGROUND: The use of molecular methods has led to increased detection of Enteroaggregative Escherichia coli (EAEC) in faecal samples. Studies have yielded conflicting results regarding the clinical relevance of this finding. The objective of this study was to investigate the prevalence of EAEC in faecal samples from patients with diarrhoea and healthy controls and describe characteristics of EAEC positive persons. METHODS: From March 1st, 2017 to February 28th, 2019, we investigated all consecutive faecal samples from patients with diarrhoea received at the laboratory and collected faecal samples from randomly invited healthy controls from mid-Norway. Real-time multiplex PCR was used for detection of bacterial, viral, and parasitic pathogens. We registered sex, age, urban versus non-urban residency, and travel history for all participants. Statistical analyses were performed with Pearson chi-squared test, Kruskal-Wallis test, and Mann-Whitney U test. RESULTS: We identified EAEC in 440 of 9487 (4.6%) patients with diarrhoea and 8 of 375 (2.2%) healthy controls. The EAEC prevalence was 19.1% among those with diarrhoea and recent foreign travel and 2.2% in those without travel history independent of diarrhoea. Concomitant pathogens were detected in 64.3% of EAEC-positive patients with diarrhoea. The median age was 28.5 in those with EAEC-positive diarrhoea and 38 in those with EAEC-negative diarrhoea (p <0.01). In patients with diarrhoea, travel was reported in 72% of those with EAEC and concomitant pathogens, and 54% and 12% in those with only EAEC and no EAEC, respectively (p <0.01). CONCLUSIONS: EAEC was a common detection, particularly in patients with diarrhoea and recent international travel, and was found together with other intestinal pathogens in the majority of cases. Our results suggest that domestically acquired EAEC is not associated with diarrhoea. Patients with EAEC-positive diarrhoea and concomitant pathogens were young and often reported recent travel history compared to other patients with diarrhoea.

The combination of pleconaril, rupintrivir, and remdesivir efficiently inhibits enterovirus infections in vitro, delaying the development of drug-resistant virus variants.

Enteroviruses are a significant global health concern, causing a spectrum of diseases from the common cold to more severe conditions like hand-foot-and-mouth disease, meningitis, myocarditis, pancreatitis, and poliomyelitis. Current treatment options for these infections are limited, underscoring the urgent need for effective therapeutic strategies. To find better treatment option we analyzed toxicity and efficacy of 12 known broad-spectrum anti-enterovirals both individually and in combinations against different enteroviruses in vitro. We identified several novel, synergistic two-drug and three-drug combinations that demonstrated significant inhibition of enterovirus infections in vitro. Specifically, the triple-drug combination of pleconaril, rupintrivir, and remdesivir exhibited remarkable efficacy against echovirus (EV) 1, EV6, EV11, and coxsackievirus (CV) B5, in human lung epithelial A549 cells. This combination surpassed the effectiveness of single-agent or dual-drug treatments, as evidenced by its ability to protect A549 cells from EV1-induced cytotoxicity across seven passages. Additionally, this triple-drug cocktail showed potent antiviral activity against EV-A71 in human intestinal organoids. Thus, our findings highlight the therapeutic potential of the pleconaril-rupintrivir-remdesivir combination as a broad-spectrum treatment option against a range of enterovirus infections. The study also paves the way towards development of strategic antiviral drug combinations with virus family coverage and high-resistance barriers.

Comparisons of infant Escherichia coli isolates link genomic profiles with adaptation to the ecological niche.

BACKGROUND: Despite being one of the most intensely studied model organisms, many questions still remain about the evolutionary biology and ecology of Escherichia coli. An important step toward achieving a more complete understanding of E.coli biology entails elucidating relationships between gene content and adaptation to the ecological niche. RESULTS: Here, we present genome comparisons of 16 E.coli strains that represent commensals and pathogens isolated from infants during a specific time period in Trondheim, Norway. Using differential gene content, we characterized enrichment profiles of the collection of strains relating to phylogeny, early vs. late colonization, pathogenicity and growth rate. We found clear gene content distinctions relating to the various grouping criteria. We also found that different categories of strains use different genetic elements for similar biological processes. The sequenced genomes included two pairs of strains where each pair was isolated from the same infant at different time points. One pair, in which the strains were isolated four months apart, showed maintenance of an early colonizer genome profile but also gene content and codon usage changes toward the late colonizer profile. Lastly, we placed our sequenced isolates into a broader genomic context by comparing them with 25 published E.coli genomes that represent a variety of pathotypes and commensal strains. This analysis demonstrated the importance of geography in shaping strain level gene content profiles. CONCLUSIONS: Our results indicate a general pattern where alternative genetic pathways lead toward a consistent ecological role for E.coli as a species. Within this framework however, we saw selection shaping the coding repertoire of E.coli strains toward distinct ecotypes with different phenotypic properties.

Role of fungal burden in risk stratification of HIV-negative patients with Pneumocystis pneumonia: A 12-year, retrospective, observational, multicenter cohort.

OBJECTIVES: This study aimed to explore the role of fungal burden in risk stratification of patients without HIV-negative patients with Pneumocystis pneumonia (PCP). METHODS: This was a retrospective analysis of the characteristics associated with 30-day mortality in patients who were positive for P. jirovecii using polymerase chain reaction in bronchoalveolar lavage fluid between 2006 and 2017 in a multicenter cohort from Central Norway. The fungal burden was indicated by the cycle threshold (CT) values from semiquantitative real-time polymerase chain reaction targeting the ß-tubulin gene. RESULTS: We included 170 patients with proven or probable PCP. The all-cause 30-day mortality was 18.2%. After adjusting for host characteristics and premorbid corticosteroid use, a higher fungal burden was associated with a higher risk of dying: adjusted odds ratio 1.42 (95% confidence interval 0.48-4.25) for a CT value 31-36, increasing to odds ratio 5.43 (95% confidence interval 1.48-19.9) for a CT value ≤30 compared with patients with a CT value ≥37. The Charlson comorbidity index (CCI) improved the risk stratification: patients with a CT value ≥37 and CCI ≤2 had a 9% mortality risk compared with 70% among those with a CT value ≤30 and CCI ≥6. Comorbid cardiovascular disease, solid tumors, immunological disorders, premorbid corticosteroids, hypoxemia, abnormal leukocyte counts, low serum albumin, and C-reactive protein ≥100 were also independently associated with 30-day mortality. The sensitivity analyses did not suggest selection bias. CONCLUSION: Fungal burden may improve the risk stratification of patients without HIV-negative patients with PCP.

High levels of discordant antimicrobial therapy in hospital-acquired bloodstream infections is associated with increased mortality in an intensive care, low antimicrobial resistance setting.

BACKGROUND: Bloodstream infections (BSI) occur frequently and are associated with severe outcomes. In this study we aimed to investigate proportions of patients that received discordant empirical antimicrobial therapy and its association to mortality. METHODS: A retrospective cohort study model was undertaken to outline BSI in an intensive care, single centre, and low antimicrobial resistance prevalence setting. We used descriptive statistics to delineate proportions of patients that received discordant empirical antimicrobial therapy, and a correlation model and a logistic regression model to calculate the association with mortality and predictors of receiving discordant therapy, respectively. RESULTS: From 2014 to 2018 we included 270 BSI episodes, of which one third were hospital-acquired. Gram negative, Gram positive, and anaerobic pathogens were detected in 49.0%, 45.3% and 5.7% respectively. The proportion of isolates that conferred extended-spectrum beta-lactamase (ESBL) properties were 5.9% among enterobactereales, and no methicillin-resistant Staphylococcus aureus isolates were detected. Empirical antimicrobial therapy for community-acquired (CA) and hospital-acquired (HA) BSI were discordant at day 0 in 6.5% and 24.4%, respectively (p<.001). Discordant therapy was significantly associated with mortality at day 28 (p=.041). HA-onset BSI, enterococcal BSI and BSI of intraabdominal origin were statistically significant predictors of receiving discordant therapy. CONCLUSION: A significant proportion of HA-BSI did not receive effective antimicrobial therapy and this was significantly associated with mortality. The results underscore the need for more accurate diagnostic tools, improved communication between the microbiological laboratory and the clinicians, and antimicrobial stewardship measures.

Empirical antimicrobial therapy for bloodstream infections not compliant with guideline was associated with discordant therapy, which predicted poorer outcome even in a low resistance environment.

OBJECTIVES: To characterise all bloodstream infections (BSIs) in a low antimicrobial resistance (AMR) prevalence setting with regard to the appropriateness of empirical antimicrobial therapy, compliance with the national clinical practice guideline, de-escalation practice and outcome. METHODS: A retrospective observational study including patients aged ≥ 18 years admitted to a university hospital in central Norway with positive blood culture in 2019. RESULTS: We included 756 BSI episodes in our analysis. Empirical antimicrobial therapy was in accordance with the national guideline in 534 (70.6%), and not in accordance in 190 (25.1%) of the BSI episodes. There was a statistically significant association between compliance with the national guideline and concordant empirical antimicrobial therapy (p = .001). De-escalation of antimicrobial therapy was possible but not done in 217 (31.1%) of the BSI episodes. Variables identified as independent predictors of discordant empirical antimicrobial therapy included hospital department, type of empirical antimicrobial regimen, bacterial species, and AMR. Independent predictors of intra-hospital case fatality rate were coverage of empirical antimicrobial therapy, CCI-score, SAPS-II score, site of infection, and type of empirical antimicrobial regimen. Furthermore, the intra-hospital and long-term unadjusted all-cause case fatality rates were increased (p < .001, log-rank test for overall difference in survival) for the patients who received discordant empirical antimicrobial therapy. CONCLUSION: Our study shows that empirical antimicrobial therapy initiated in accordance with national guideline recommendations increases the likelihood of receiving concordant therapy. Discordant empirical antimicrobial therapy was associated with poorer outcomes, even in a setting with low AMR prevalence.

Phenotypic and genotypic characterisation of thymine auxotrophy in Escherichia coli isolated from a patient with recurrent bloodstream infection.

INTRODUCTION: Thymine auxotrophic in vitro mutants of Escherichia coli were first reported in the mid-20th century. Later, thymine-dependent clinical strains of E. coli as well as other Enterobacterales, Enterococcus faecalis and Staphylococcus aureus have been recognized as the cause of persistent and recurrent infections. OBJECTIVES: The aim of this study was to characterize the phenotype and investigate the molecular basis of thymine auxotrophy in ten E. coli isolates obtained at different time points from a patient with recurrent bloodstream infection (BSI) due to a chronic aortic graft infection treated with Trimethoprim/sulfamethoxazole (TMP-SMX). METHODS: Clinical data was obtained from hospital records. Growth characterization and antimicrobial susceptibility testing to TMP-SMX was performed on M9 agar and in MH broth with different thymine concentrations (0.5, 2, 5, 10 and 20 µg/mL), on Mueller-Hinton (MH) and blood agar. Whole genome sequencing (WGS) was performed on all E. coli isolates. RESULTS: E. coli were isolated from ten consecutive BSI episodes from a patient with chronic aortic graft infection. Six of these isolates were resistant to TMP-SMX when assayed on blood agar. Growth experiments with added thymine confirmed that these isolates were thymine-dependent (thy-), and revealed growth defects (slower growth rate and smaller colony size) in these isolates relative to thy+ isolates (n = 4). WGS indicated that all isolates were of the same clonal lineage of sequence type 7358. Genomic analysis revealed a G172C substitution in thyA in all TMP-SMX resistant isolates, while mutations affecting genes involved in the deoxyribose salvage pathway (deoB and deoC) were identified in eight isolates. CONCLUSION: This case highlights the risk of resistance development to TMP-SMX, especially for long-term treatment, and the possible pitfalls in detection of growth-deficient subpopulations from chronic infections, which could lead to treatment failure.

The Streptococcus agalactiae R3 surface protein is encoded by sar5.

Streptococcus agalactiae (group B streptococcus; GBS) is an important human pathogen causing pneumonia, sepsis and meningitis in neonates, as well as infections in pregnant women, immunocompromised individuals, and the elderly. For the future control of GBS-inflicted disease, GBS surface exposed proteins are particularly relevant as they may act as antigens for vaccine development and/or as serosubtype markers in epidemiological settings. Even so, the genes encoding some of the surface proteins established as serosubtype markers by antibody-based methods, like the R3 surface protein, are still unknown. Here, by examining a Norwegian GBS collection consisting of 140 strains, we find that R3 protein expression correlates with the presence of the gene sar5. By inducible expression of sar5 in an R3-negative bacterial strain we show that the sar5 gene product is specifically recognized by an R3 monoclonal antibody. With this we identify sar5 as the gene encoding the R3 surface protein, a serosubtype marker of hitherto unknown genetic origin.

Novel Synergistic Anti-Enteroviral Drug Combinations.

Background: Enterovirus infections affect people around the world, causing a range of illnesses, from mild fevers to severe, potentially fatal conditions. There are no approved treatments for enterovirus infections. Methods: We have tested our library of broad-spectrum antiviral agents (BSAs) against echovirus 1 (EV1) in human adenocarcinoma alveolar basal epithelial A549 cells. We also tested combinations of the most active compounds against EV1 in A549 and human immortalized retinal pigment epithelium RPE cells. Results: We confirmed anti-enteroviral activities of pleconaril, rupintrivir, cycloheximide, vemurafenib, remdesivir, emetine, and anisomycin and identified novel synergistic rupintrivir-vemurafenib, vemurafenib-pleconaril and rupintrivir-pleconaril combinations against EV1 infection. Conclusions: Because rupintrivir, vemurafenib, and pleconaril require lower concentrations to inhibit enterovirus replication in vitro when combined, their cocktails may have fewer side effects in vivo and, therefore, should be further explored in preclinical and clinical trials against EV1 and other enterovirus infections.

Semiquantitative Real-Time PCR to Distinguish Pneumocystis Pneumonia from Colonization in a Heterogeneous Population of HIV-Negative Immunocompromised Patients.

Pneumocystis jirovecii is a threat to iatrogenically immunosuppressed individuals, a heterogeneous population at rapid growth. We assessed the ability of an in-house semiquantitative real-time PCR assay to discriminate Pneumocystis pneumonia (PCP) from colonization and identified risk factors for infection in these patients. Retrospectively, 242 PCR-positive patients were compared according to PCP status, including strata by immunosuppressive conditions, human immunodeficiency virus (HIV) infection excluded. Associations between host characteristics and cycle threshold (CT) values, semiquantitative real-time PCR correlates of fungal loads in lower respiratory tract specimens, were investigated. CT values differed significantly according to PCP status. Overall, a CT value of 36 allowed differentiation between PCP and colonization with sensitivity and specificity of 71.3% and 77.1%, respectively. A CT value of less than 31 confirmed PCP, whereas no CT value permitted exclusion. A considerable diversity was uncovered; solid organ transplant (SOT) recipients had significantly higher fungal loads than patients with hematological malignancies. In SOT recipients, a CT cutoff value of 36 resulted in sensitivity and specificity of 95.0% and 83.3%, respectively. In patients with hematological malignancies, a higher CT cutoff value of 37 improved sensitivity to 88.5% but reduced specificity to 66.7%. For other conditions, assay validity appeared inferior. Corticosteroid usage was an independent predictor of PCP in a multivariable analysis and was associated with higher fungal loads at PCP expression. Semiquantitative real-time PCR improves differentiation between PCP and colonization in immunocompromised HIV-negative individuals with acute respiratory syndromes. However, heterogeneity in disease evolution requires separate cutoff values across intrinsic and iatrogenic predisposition for predicting non-HIV PCP. IMPORTANCE Pneumocystis jirovecii is potentially life threatening to an increasing number of individuals with compromised immune systems. This microorganism can cause severe pneumonia in susceptible hosts, including patients with cancer and autoimmune diseases and people undergoing solid organ transplantation. Together, these patients constitute an ever-diverse population. In this paper, we demonstrate that the heterogeneity herein has important implications for how we diagnose and assess the risk of Pneumocystis pneumonia (PCP). Specifically, low loads of microorganisms are sufficient to cause infection in patients with blood cancer compared to those in solid organ recipients. With this new insight into host versus P. jirovecii biology, clinicians can manage patients at risk of PCP more accurately. As a result, we take a significant step toward offering precision medicine to a vulnerable patient population. One the one hand, these patients have propensity for adverse effects from antimicrobial treatment. On the other hand, this population is susceptible to life-threatening infections, including PCP.