A Real-World Study on the Clinical Characteristics, Outcomes, and Relationship between Antibiotic Exposure and Clostridioides difficile Infection

Clostridioides difficile is a Gram-positive bacteria that causes nosocomial infections, significantly impacting public health. In the present study, we aimed to describe the clinical characteristics, outcomes, and relationship between antibiotic exposure and Clostridioides difficile infection (CDI) in patients based on reports from two databases. Thus, we conducted a retrospective study of patients diagnosed with CDI from Sibiu County Clinical Emergency Hospital (SCCEH), Romania, followed by a descriptive analysis based on spontaneous reports submitted to the EudraVigilance (EV) database. From 1 January to 31 December 2022, we included 111 hospitalized patients with CDI from SCCEH. Moreover, 249 individual case safety reports (ICSRs) from EVs were analyzed. According to the data collected from SCCEH, CDI was most frequently reported in patients aged 65-85 years (66.7%) and in females (55%). In total, 71.2% of all patients showed positive medical progress. Most cases were reported in the internal medicine (n = 30, 27%), general surgery (n = 26, 23.4%), and infectious disease (n = 22, 19.8%) departments. Patients were most frequently exposed to ceftriaxone (CFT) and meropenem (MER). Also, in the EV database, most CDI-related ADRs were reported for CFT, PIP/TAZ (piperacillin/tazobactam), MER, and CPX (ciprofloxacin). Understanding the association between previous antibiotic exposure and the risk of CDI may help update antibiotic stewardship protocols and reduce the incidence of CDI by lowering exposure to high-risk antibiotics.

Prognostic Factors of Platinum-Refractory Advanced Urothelial Carcinoma Treated with Pembrolizumab

INTRODUCTION

Immune checkpoint inhibitor (ICI) therapy has significantly improved the prognosis of some patients with advanced urothelial carcinoma (UC), but it does not provide high therapeutic efficacy in all patients. Therefore, identifying predictive biomarkers is crucial in determining which patients are candidates for ICI treatment. This study aimed to identify the predictors of ICI treatment response in patients with platinum-refractory advanced UC treated with pembrolizumab.

METHODS

Patients with platinum-refractory advanced UC who had received pembrolizumab at two hospitals in Japan were included. Univariate and multivariate analyses were performed to identify biomarkers for progression-free survival (PFS) and overall survival (OS).

RESULTS

Forty-one patients were evaluable for this analysis. Their median age was 75 years, and the vast majority of the patients were male (85.4%). The objective response rate was 29.3%, with a median overall survival (OS) of 17.8 months. On multivariate analysis, an Eastern Cooperative Oncology Group performance status (ECOG-PS) ≥ 2 (HR = 6.33, p = 0.03) and a baseline neutrophil-to-lymphocyte ratio (NLR) > 3 (HR = 2.79, p = 0.04) were significantly associated with poor OS. Antibiotic exposure did not have a significant impact on either PFS or OS.

CONCLUSIONS

ECOG-PS ≥ 2 and baseline NLR > 3 were independent risk factors for OS in patients with platinum-refractory advanced UC treated with pembrolizumab. Antibiotic exposure was not a predictor of ICI treatment response.

[Antimicrobial stewardship program in an Intensive Care Unit: A retrospective observational analysis of the results 15 months after its implementation]

OBJECTIVE

We aim to evaluate the adherence rate to an Antimicrobial Stewardship Program (ASP) in an Intensive Care Unit (ICU), and to assess its effect on the use of antibiotics, quality indicators and clinical outcomes.

METHODS

Retrospective description of the interventions proposed by the ASP. We compared antimicrobial use, quality and safety indicators in an ASP versus a non-ASP period. The study was performed in a polyvalent ICU of a medium-size University Hospital (600 beds). We studied patients admitted to the ICU for any cause during the ASP period, provided that a microbiological sample aiming to diagnose a potential infection has been drawn, or antibiotics have been started. We elaborated and registered of non-mandatory recommendations to improve antimicrobial prescription (audit and feedback structure) and its registry during the ASP period (15 months, October 2018-December 2019). We compared indicators in a period with ASP (April-June 2019) and without ASP (April-June 2018).

RESULTS

We issued 241 recommendations on 117 patients, 67% of them classified as de-escalation type. The rate of adherence to the recommendations was high (96.3%). In the ASP period, the mean number of antibiotics per patient (3.3±4.1 vs 2.4±1.7, p=0.04) and the days of treatment (155 DOT/100 PD vs 94 DOT/100 PD, p <0.01) were reduced. The implementation of the ASP did not compromise patient safety or produce changes in clinical outcomes.

CONCLUSIONS

The implementation of an ASP is widely accepted in the ICU, reducing the consumption of antimicrobials, without compromising patient safety.

Previous Antibiotic Exposure Reshapes the Population Structure of Infecting Uropathogenic Escherichia coli Strains by Selecting for Antibiotic Resistance over Urovirulence

Antibiotic therapy is the standard of care for urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC). However, previous antibiotic therapy may impart a selective pressure that influences the population structure and pathogenic potential of infecting UPEC strains. Here, we conducted a 3-year study using whole-genome-sequencing analysis and retrospective medical record review to characterize how antibiotic exposure influenced the phenotypic antibiotic resistance, acquired resistome, virulome, and population structure of 88 UTI-causing E. coli strains from dogs. A majority of UTI-associated E. coli strains were from phylogroup B2 and clustered within sequence type 372. Previous antibiotic exposure was associated with a population shift toward UPEC from phylogroups other than the typical urovirulent phylogroup B2. The specific virulence profiles within the accessory virulome that were associated with antibiotic use were elicited by the effect of antibiotics on UPEC phylogenetic structure. Among phylogroup B2, antibiotic exposure increased the quantity of genes within the resistome and the odds of developing reduced susceptibility to at least one antibiotic. Non-B2 UPEC strains harbored a more diverse and greater resistome that conferred reduced susceptibility to multiple antibiotic classes following antibiotic exposure. Collectively, these data suggest that previous antibiotic exposure establishes an environment that provides a selective edge to non-B2 UPEC strains through their diverse and abundant antibiotic resistance genes, despite their lack of urovirulence genes. Our findings highlight the necessity for judicious use of antibiotics as we uncover another mechanism by which antibiotic exposure and resistance can influence the dynamics of bacterial infectious disease. IMPORTANCE Urinary tract infections (UTIs) are one of the most common infections of dogs and humans. While antibiotic therapy is the standard of care for UTIs and other infections, antibiotic exposure may influence the pathogenic profile of subsequent infections. We used whole-genome sequencing and retrospective medical record review to characterize the effect of systemic antibiotic therapy on the resistance, virulence, and population structure of 88 UTI-causing UPEC strains isolated from dogs. Our results indicate that antibiotic exposure alters the population structure of infecting UPEC strains, providing a selective edge for non-B2 phylogroups that harbor diverse and abundant resistance gene catalogues but fewer urovirulence genes. These findings highlight how antibiotic resistance can influence pathogen infection dynamics and have clinical implications for the judicious use of antibiotics for bacterial infections.

Relationship between antibiotic exposure and carbapenem-resistant Klebsiella pneumoniae infection within four types of control patients: a systematic review and meta-analysis

OBJECTIVES

This study attempted to identify the relationship between antibiotic exposure and carbapenem-resistant Klebsiella pneumoniae (CRKP) infection.

METHODS

Antibiotic exposure were chosen as the risk factors for CRKP infection, which were extracted from research articles indexed in PubMed, EMBASE and Cochrane Library. Relevant studies published until January 2023 were reviewed, and a meta-analysis was conducted on antibiotic exposure within the four types of control groups, which comprised of 52 studies.

RESULTS

The meta-analysis was performed within four types of control groups: patients infected with carbapenem-susceptible Klebsiella pneumoniae (comparison 1), other infection especially without CRKP infection (comparison 2), CRKP colonization (comparison 3) and no infection (comparison 4). The two risk factors were common to the four comparisons according to Carbapenem and Aminoglycoside exposure. Compared to Carbapenem-susceptible Klebsiella pneumoniae (CSKP) infection, Tegacyclin exposure in bloodstream infection and Quinolone exposure within 30 days were associated with increased risk for CRKP infection. However, Tegacyclin exposure in MIX infection (MIX infection included two or more different infection sites) and Quinolone exposure within 90 days possessed a similar risk for both CRKP and CSKP infection.

CONCLUSIONS

Carbapenem and Aminoglycoside exposure serve as likely risk factors for CRKP infection. Meanwhile, antibiotic exposure time as continuous variables was not related to CRKP infection compared to CSKP infection. Tigecycline exposure in MIX infection and Quinolone exposure within 90 days may not increase the risk of CRKP infection.

A European International Multicentre Survey on the Current Practice of Perioperative Antibiotic Prophylaxis for Paediatric Liver Transplantations

(1) Background: Postoperative infections are major contributors of morbidity and mortality after paediatric liver transplantation (pLTX). Evidence and recommendations regarding the most effective antimicrobial strategy are lacking. (2) Results: Of 39 pLTX centres, 20 responded. Aminopenicillins plus ß-lactamase inhibitors were used by six (30%) and third generation cephalosporins by three (15%), with the remaining centres reporting heterogenous regimens. Broad-spectrum regimens were the standard in 10 (50%) of centres and less frequent in the 16 (80%) centres with an infectious disease specialist. The duration ranged mainly between 24-48 h and 3-5 days in the absence and 3-5 days or 6-10 days in the presence of risk factors. Strategies regarding antifungal, antiviral, adjunctive antimicrobial, and surveillance strategies varied widely. (3) Methods: This international multicentre survey endorsed by the European Liver Transplant Registry queried all European pLTX centres from the registry on their current practice of perioperative antibiotic prophylaxis and antimicrobial strategies via an online questionnaire. (4) Conclusions: This survey found great heterogeneity regarding all aspects of postoperative antimicrobial treatment, surveillance, and prevention of infections in European pLTX centres. Evidence-based recommendations are urgently needed to optimise antimicrobial strategies and reduce the spectrum and duration of antimicrobial exposure.

Relationships between antibiotic exposure and asthma in adults in the United States: results of the National Health and Nutrition Examination Survey between 1999 and 2018

Objectives

To investigate the relationship between antibiotic exposure and asthma in adults in the United States.

Methods

Data was obtained from the National Health and Nutrition Examination Survey (NHANES) conducted between 1999 and 2018. A total of 51,124 participants were included, excluding those who were aged < 20 years, female participants who were pregnant, and individuals who did not complete the prescription medications questionnaire and the medical conditions questionnaire regarding asthma status. Antibiotic exposure was defined as the utilization of antibiotics within the past 30 days, categorized based on the Multum Lexicon Plus therapeutic classification system. Asthma was defined as having a history of asthma or having an asthma attack or wheezing symptoms in the past year.

Results

The risk of asthma was found to be 2.557 (95% CI: 1.811, 3.612), 1.547 (95% CI: 1.190, 2.011) and 2.053 (95% CI: 1.344, 3.137) times greater in participants who had used macrolide derivatives, penicillin and quinolones in the past 30 days, respectively, compared with those not using antibiotics. After adjusting for demographic covariates and asthma-related factors, only macrolides derivatives were significantly associated with asthma in the 20-40 and 40-60 age groups. For individuals over 60 years old, quinolones were significantly associated with asthma. The effect of different types of antibiotic with asthma varied in male and female populations. Moreover, higher socioeconomic status, greater BMI, younger age, smoking habits, history of infection, chronic bronchitis, emphysema, and family history of asthma were all identified as risk factors for asthma.

Conclusion

Our study indicated that three types of antibiotics were significantly associated with asthma in different subgroups of the population. Therefore, the use of antibiotics should be more strictly regulated.

Early-life antibiotic exposure increases the risk of childhood overweight and obesity in relation to dysbiosis of gut microbiota: a birth cohort study

Background

Early-life antibiotic exposure is associated with the development of later obesity through the disruption of gut microbiota in the animal models. However, the related epidemiological evidence is still conflicting.

Methods

A birth cohort was consisted of 2140 mother-infant pairs in Chaoyang District Maternal and Child Health Care Hospital in this study. Here, their available antibiotic exposure during the first one year of life was ascertained using a open-ended questionnaire and related anthropometric parameters from the health screening program. The compositions of gut microbiota were comprehensively analyzed by16S rRNA high throughput sequencing. Then the spearman correlations were performed by the multiple covariance-adjusted regressions between the antibiotic exposure with anthropometric parameters and compositions of gut microbiota.

Results

Among the 2140 subjects, the antibiotic exposure during the first one year of life was 53.04%, mainly by Cephalosporins (53.39%) and Erythromycins(27.67%) for the treatment of respiratory tract infection (79.56%), which were not significantly different among the subgroups. Compared to the control group, both childhood overweight and obesity at two and a half years were higher in the antibiotic exposed group, with higher percents of Faecalibacterium, Agathobacter and Klebsiella, and lower percentage of Bifidobacterium. Moreover, there were positively potential associations between early-life antibiotic exposure with the accelerated anthropometric parameters and disruption of Faecalibacterium, Agathobacter, Klebsiella and Bifidobacterium at two and a half years.

Conclusion

These above results proved that early-life antibiotic exposure was positively associated with the accelerated childhood overweight and obesity from one year to two and a half years by impacting the disorders of Faecalibacterium, Agathobacter, Klebsiella and Bifidobacterium, which would propose the theoretical basis for rationalizing the personalized antibiotic exposure among the infants to truly reflect the fairness of public health.

Supplementary information

The online version contains supplementary material available at 10.1186/s12941-022-00535-1.

Longitudinal analysis of exposure to a low concentration of oxytetracycline on the zebrafish gut microbiome

Oxytetracycline, a widely produced and administered antibiotic, is uncontrollably released in low concentrations in various types of environments. However, the impact of exposure to such low concentrations of antibiotics on the host remains poorly understood. In this study, we exposed zebrafish to a low concentration (5,000 ng/L) of oxytetracycline for 1 month, collected samples longitudinally (Baseline, and Days 3, 6, 9, 12, 24, and 30), and elucidated the impact of exposure on microbial composition, antibiotic resistance genes, mobile genetic elements, and phospholipid metabolism pathway through comparison of the sequenced data with respective sequence databases. We identified Pseudomonas aeruginosa, a well-known pathogen, to be significantly positively associated with the duration of oxytetracycline exposure (Adjusted P = 5.829e-03). Several tetracycline resistance genes (e.g., tetE) not only showed significantly higher abundance in the exposed samples but were also positively associated with the duration of exposure (Adjusted P = 1.114e-02). Furthermore, in the exposed group, the relative abundance of genes involved in phospholipid metabolism had also decreased. Lastly, we characterized the impact of exposure on zebrafish intestinal structure and found that the goblet cell counts were decreased (~82%) after exposure. Overall, our results show that a low concentration of oxytetracycline can increase the abundance of pathogenic bacteria and lower the abundance of key metabolic pathways in the zebrafish gut microbiome that can render them prone to bacterial infections and health-associated complications.

Association of Blood Biochemical Indexes and Antibiotic Exposure With Severe Immune-related Adverse Events in Patients With Advanced Cancers Receiving PD-1 Inhibitors

Some patients with cancer treated with programmed death 1 (PD-1) inhibitors experience immune-related severe adverse events (ir-SAEs), however, predictors are limited. The objective was to identify clinicopathologic features that may be associated with a higher ir-SAE risk. This was a nested case-control study. After screening a total of 832 PD-1 inhibitor-treated patients, we identified 42 ir-SAE cases. According to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, ir-SAEs were defined as grade ≥3 toxic effects associated with immunotherapy. A total of 126 controls were matched. The crude and adjusted risks of ir-SAEs were estimated by odds ratio (ORs) and 95% CIs using multivariate logistic regression models. Baseline neutrophil-to-lymphocyte ratio (NLR) [per SD increment-adjusted (aOR): 1.16], lactate dehydrogenase (LDH) ≥245 U/L (aOR: 2.39), and antibiotic exposure (aOR: 4.39) were associated with a higher risk of ir-SAEs. When NLR was categorized in 3 groups, significantly higher risks of ir-SAEs (aOR: 4.95) were found in participants in group 3 (>6) than in those in group 1 (<3). Furthermore, NLR (per SD increment-adjusted hazard ratio:1.08) were also significantly associated with shorter overall survival (OS). Baseline LDH ≥245 U/L and antibiotic exposure were no significant association with OS. In conclusion, ir-SAEs were associated between baseline NLR, LDH ≥245 U/L and antibiotic exposure. Lower NLR was correlated with longer OS for cancer.

Characterization of the Ocular Surface Microbiome in Keratitis Patients after Repeated Ophthalmic Antibiotic Exposure

In human medicine, antibiotics have been widely used to treat microbial infections. The extensive use of antibiotics is a leading cause of antibiotic resistance. Currently, the influence of the use of antibiotics on the ocular surface microbiome in the course of keratitis treatment remains to be explored in depth. We performed metagenomic analyses in a cohort of 26 healthy controls (HCs), 28 keratitis patients (KPs) who received antibiotics [KP (abx+) group], and 12 KPs who were antibiotic naive [KP (abx-) group]. We identified that the dissimilarities in microbial community structure (Bray-Curtis and Jaccard analyses) between the KP (abx+) group and the HC group were greater than those between the KP (abx-) group and the HC group. Pseudomonas lactis, P. aeruginosa, Pseudomonas sp. FDAARGOS_380, Pseudomonas sp. J380, Corynebacterium simulans, Streptococcus pyogenes, Finegoldia magna, and Aspergillus oryzae had no statistically significant differences between the KP (abx+) and KP (abx-) groups but did have statistically significant differences between the KP (abx+) and HC groups and between the KP (abx-) and HC groups. Among them, Pseudomonas lactis, P. aeruginosa, Pseudomonas sp. FDAARGOS_380, and Pseudomonas sp. J380 were identified as possible hosts carrying multidrug-resistant genes. The total abundance and number of antibiotic resistance genes (ARGs) were greater in the KP (abx+) group than in the HC and KP (abx-) groups. The functional profile analysis of ocular surface microbiota revealed that pathogenesis-related functional pathways and virulence functions were enriched in KPs. In conclusion, our results show that empirical antibiotic treatment in KPs leads to increases in the antibiotic resistance of ocular surface microbiota. IMPORTANCE Treatment for keratitis is based on appropriate antimicrobial therapy. A direct correlation between antibiotic use and the extent of antibiotic resistance has been reported. Therefore, knowledge of the antibiotic resistance patterns of ocular surface microbial flora in KPs is important for clinical treatment. To the best of our knowledge, this is the first study to use metagenomic approaches to investigate the associations between ophthalmic antibiotic use and the ocular surface microbiome of KPs. Monitoring the microbiota and antibiotic resistome profiles for the ocular surface has huge potential to help ophthalmologists choose the appropriate antibiotics and will thereby improve the efficacy of treatment regimens, which has important implications for reducing the development of antibiotic resistance of the ocular surface to a certain extent.

The Effect of Pharmacist-Led Intervention on Surgical Antibacterial Prophylaxis (SAP) at an Orthopedic Unit

Perioperative antibiotic use is a common reason for antibiotic misuse. Evidence suggests that adherence to SAP guidelines may improve outcomes. The purpose of this study was to analyze the impact of pharmacist-led antibiotic stewardship interventions on SAP guideline compliance. The study was conducted at an Orthopedic Department of a tertiary care medical center. SAP compliance and antibiotic exposure in the pre-intervention and intervention period was compared using chi-square, Fisher exact, and Mann-Whitney tests, as appropriate. Prophylactic antibiotic use in orthopedic joint arthroplasties (overall guideline adherence: agent, dose, frequency, duration), clinical outcomes (length of stay-LOS, number of surgical site infections-SSIs), antibiotic exposure and direct antibiotic costs were compared between pre-intervention and intervention periods. Significant improvement in mean SAP duration (by 42.9%, 4.08 ± 2.08 vs. 2.08 ± 1.90 days, p ˂ 0.001), and overall guideline adherence regarding antibiotic use (by 56.2%, from 2% to 58.2%, p ˂ 0.001) were observed. A significant decrease was observed in antibiotic exposure in SAP (by 41%, from 6.07 ± 0.05 to 3.58 ± 4.33 DDD/patient, p ˂ 0.001), average prophylactic antibiotic cost (by 54.8%, 9278.79 ± 6094.29 vs. 3598.16 ± 3354.55 HUF/patient), and mean LOS (by 37.2%, from 11.22 ± 6.96 to 7.62 ± 3.02 days, p < 0.001); and a slight decrease in the number of confirmed SSIs was found between the two periods (by 1.8%, from 3% to 1.2%, p = 0.21). Continuous presence of the clinical pharmacist led to significant improvement in SAP guideline adherence, which was accompanied by decreased antibiotic exposure and cost.

Citrus reticulatae pericarpium Extract Decreases the Susceptibility to HFD-Induced Glycolipid Metabolism Disorder in Mice Exposed to Azithromycin in Early Life

Background

Studies have shown that gut microbe disorder in mice due to early-life antibiotic exposure promotes glycolipid metabolism disorder in adulthood. However, the underlying mechanism remains unclear and there is not yet an effective intervention or treatment for this process.

Purpose

The study investigated whether early-life azithromycin (AZT) exposure in mice could promote high-fat diet (HFD)-induced glycolipid metabolism disorder in adulthood. Moreover, the effect of citrus reticulata pericarpium (CRP) extract on glycolipid metabolism disorder via regulation of gut microbiome in mice exposed to antibodies early in life were investigated.

Methods and Results

Three-week-old mice were treated with AZT (50 mg/kg/day) via drinking water for two weeks and then were fed a CRP diet (1% CRP extract) for four weeks and an HFD for five weeks. The results showed that early-life AZT exposure promoted HFD-induced glycolipid metabolism disorder, increased the levels of inflammatory factors, promoted the flora metabolism product trimethylamine N-oxide (TMAO), and induced microbial disorder in adult mice. Importantly, CRP extract mitigated these effects.

Conclusion

Taken together, these findings suggest that early-life AZT exposure increases the susceptibility to HFD-induced glycolipid metabolism disorder in adult mice, and CRP extract can decrease this susceptibility by regulating gut microbiome.

Newborns with Bloody Stools-At the Crossroad between Efficient Management of Necrotizing Enterocolitis and Antibiotic Stewardship

The onset of bloody stools in neonates often results in antibiotic treatment for suspected necrotizing enterocolitis (NEC). Food protein-induced allergic proctocolitis (FPIAP) is an often-neglected differential diagnosis. We performed a retrospective analysis of antibiotic exposure at our tertiary center from 2011 to 2020 that included three time periods of differing antimicrobial stewardship goals. We compared these data with the conventional treatment guidelines (modified Bell's criteria). In our cohort of 102 neonates with bloody stools, the length of antibiotic exposure was significantly reduced from a median of 4 to 2 days. The proportion of treated neonates decreased from 100% to 55% without an increase in negative outcomes. There were 434 antibiotic days. Following a management strategy according to modified Bell's criteria would have led to at least 780 antibiotic days. The delayed initiation of antibiotic treatment was observed in 7 of 102 cases (6.9%). No proven NEC case was missed. Mortality was 3.9%. In conclusion, with FPIAP as a differential diagnosis of NEC, an observational management strategy in neonates with bloody stools that present in a good clinical condition seems to be justified. This may lead to a significant reduction of antibiotic exposure. Further prospective, randomized trials are needed to prove the safety of this observational approach.

Comparison of Culture, Antigen Test, and Polymerase Chain Reaction for Pneumococcal Detection in Cerebrospinal Fluid of Children

Background

Sensitivity of culture for the detection of Streptococcus pneumoniae is limited by prior antibiotic exposure. Immunochromatographic test (ICT) is highly sensitive and specific for pneumococcal antigen detection in the cerebrospinal fluid (CSF) of meningitis cases. We determined the specificity and sensitivity of culture, ICT, and polymerase chain reaction (PCR) and the effect of antibiotic exposure on their performance.

Methods

CSF specimens from suspected meningitis cases admitted to Dhaka Shishu Hospital, Bangladesh, were tested using culture, ICT and PCR. Additionally, 165 specimens collected from 69 pneumococcal cases after antibiotic treatment were tested.

Results

Of 1883 specimens tested, culture detected 9, quantitative PCR (qPCR) detected 184, and ICT detected 207 pneumococcal cases (including all culture and qPCR positives). In comparison to ICT, sensitivity of culture was 4.4% and of qPCR was 90.6%; both were 100% specific. After antibiotic exposure, culture sensitivity plummeted rapidly; conventional PCR and qPCR sensitivity disappeared after day 6 and 20, respectively. ICT detected pneumococcal antigen for >10 weeks.

Conclusions

While culture provides the most information about bacterial characteristics, in high antibiotic exposure settings, ICT exhibits maximum sensitivity. We recommend culture and ICT as mainstay for pneumococcal diagnosis and surveillance; qPCR can generate additional molecular data where possible.

Use of antibiotics during pregnancy is associated with infection in children at four years of age in Portugal

AIM

To assess the association between taking antibiotics in pregnancy and the occurrence of infections in children at four years of age.

METHODS

We studied children who participated in the follow-up of the birth cohort Generation XXI, Porto-Portugal, at the age of four years. We evaluated the associations between the use of antibiotics by the mother at any time in pregnancy with the occurrence of infections. Data were analysed using logistic regression, controlling for potential confounding variables.

RESULTS

We studied 7459 children (50.7% boys). The use of antibiotics at any stage of pregnancy, and not only in the third trimester, was associated with the occurrence of tonsillitis at four years, even after controlling for potential confounders (OR 1.19, 95% CI 1.03-1.38). Other infections did not show association.

CONCLUSION

Maternal use of antibiotics during pregnancy was associated with an increased risk of tonsillitis reported at four years of age. Antibiotics could favour the potential transmission of an unfavourable microbiome from mother to child.

A Case of Primary Ciliary Dyskinesia Caused by a Mutation in OFD1, Which Was Diagnosed Owing to Clostridium difficile Infection

We report a Japanese 5-year-old boy with primary ciliary dyskinesia (PCD) which was diagnosed owing to Clostridium difficile (CD) infection caused by prolonged antibiotic exposure. He had intractable otitis media with effusion (OME) and had abdominal pain and diarrhea for 4 months after starting antibiotics administration. His stool contained CD toxin. After vancomycin treatment, his symptoms improved and his stools did not contain CD toxin. His past medical history included frequent pneumonia. We, therefore, performed electron microscopy of the biopsy specimen from his nasal mucosa and genetic testing, and he was diagnosed with PCD. PCD is a rare inherited genetic disease causing ciliary dysfunction, which is very difficult to diagnose because some children without PCD also develop the same symptoms. Therefore, children who have intractable OME, rhinosinusitis, frequent pneumonia, or bronchitis and are taking antibiotics for long periods of time should be checked for underlying diseases, such as PCD.

Gut Microbiota Features on Nursing Home Admission Are Associated With Subsequent Acquisition of Antibiotic-resistant Organism Colonization

Nursing home (NH) patients often acquire colonization with antibiotic-resistant organisms (AROs). We show that patients exposed to broad-spectrum antibiotics during previous hospitalizations have elevated enterococcal relative abundances on NH admission and higher risk of subsequent ARO acquisition. Our findings suggest that interventions preventing ARO spread should extend beyond NH doors.

Prior Antibiotic Therapy and the Onset of Healthcare-Associated Infections Sustained by Multidrug-Resistant Klebsiella pneumoniae in Intensive Care Unit Patients: A Nested Case-Control Study

Epidemiological research has demonstrated direct relationships between antibiotic consumption and the emergence of multidrug-resistant (MDR) bacteria. In this nested case-control study, we assessed whether prior exposure to antibiotic therapy and its duration affect the onset of healthcare-associated infections (HAIs) sustained by MDR Klebsiella pneumoniae (MDR-Kp) in intensive care unit patients. Cases were defined as patients who developed an MDR-Kp HAI. Controls matched on sex and the length of intensive care unit (ICU) stay were randomly selected from the at-risk population. Any antibiotic agent received in systemic administration before the onset of infection was considered as antibiotic exposure. Multivariable conditional logistic regression analyses were performed to estimate the effect of prior exposure to each antibiotic class (Model 1) or its duration (Model 2) on the onset of HAIs sustained by MDR-Kp. Overall, 87 cases and 261 gender-matched controls were compared. In Model 1, aminoglycosides and linezolid independently increased the likelihood of developing an MDR-Kp HAI, whereas exposure to both linezolid and penicillins reduced the effect of linezolid alone. In Model 2, cumulative exposure to aminoglycosides increased the likelihood of the outcome, as well as cumulative exposures to penicillins and colistin, while a previous exposure to both penicillins and colistin reduced the influence of the two antibiotic classes alone. Our study confirms that aminoglycosides, penicillins, linezolid, and colistin may play a role in favoring the infections sustained by MDR-Kp. However, several double exposures in the time window before HAI onset seemed to hinder the selective pressure exerted by individual agents.

Anti-staphylococcus Antibiotics Interfere With the Transcription of Leucocidin ED Gene in Staphylococcus aureus Strain Newman

Antibiotics have been described to modulate bacterial virulence gene expression. This study aimed to assess the changes caused by anti-Staphylococcus agents in the transcription of leucocidin ED (lukED) gene of Staphylococcus aureus strain Newman in vitro and in vivo and to determine whether the altered expression is agr dependent. The bacteria were exposed to subinhibitory concentrations [1/2, 1/4, or 1/8 minimal inhibitory concentration (MIC)] of 11 antibiotics, and the expression of lukE and agr-effector RNAIII was determined using qRT-PCR. In vivo experiments were performed to evaluate the impact exerted by six representative antibiotics on the transcription of both genes. Molecular analysis showed that in vitro lukE transcription was dramatically promoted in the Newman strain exposed to sub-MICs of vancomycin, trimethoprim-sulfamethoxazole, clindamycin, gentamicin, daptomycin, and ciprofloxacin and considerably reduced when stimulated by cefazolin, erythromycin, rifampicin, tigecycline, and linezolid. In the murine abscess model, tigecycline significantly decreased the transcription of lukE and the bacterial numbers, whereas vancomycin increased them; although cefazolin increased the lukE expression (contrary to the in vitro effect), it had a remarkable role in reducing bacterial load. The correspondence analysis shows that RNAIII expression varied under seven of 11 antibiotics in vitro, and six drugs in vivo were consistent with lukE transcripts. In conclusion, our data show that anti-Staphylococcus antibiotics exert modulatory effects on lukE expression in vitro and/or in vivo, and the changed expression caused by some drugs may be involved with agr activity, thus providing a guide to choose appropriate agents to avoid promoting bacterial virulence in lukED-positive S. aureus infections.

The Association between Autism Spectrum Disorder and Pre- and Postnatal Antibiotic Exposure in Childhood-A Systematic Review with Meta-Analysis

Autism spectrum disorder (ASD) is a developmental disorder that begins in early childhood and has been associated with several environmental and genetic factors. We aimed to conduct two-side meta-analyses to determine the association between ASD and pre- and postnatal antibiotic exposure in childhood. We searched PubMed, Embase, Web of Science, and Cochrane Library for articles published up to February 2019. We evaluated observational studies that assessed the association between ASD and antibiotic exposure. Of 1459 articles, nine studies were used in the meta-analysis. We found that early antibiotic exposure, including pre- and postnatal, significantly increased the ASD risk in children. Furthermore, early antibiotic exposure, including pre- and postnatal, was significantly increased in children with ASD. Specifically, prenatal antibiotic exposure was significantly increased in children with ASD; however, postnatal antibiotic exposure was not. Our results indicate an association between ASD and early antibiotic exposure; specifically, that prenatal antibiotic exposure is an important risk factor of ASD in children.

Antibiotic exposure and 'response failure' for subsequent respiratory tract infections: an observational cohort study of UK preschool children in primary care

Background

Childhood antibiotic exposure has important clinically relevant implications. These include disruption to the microbiome, antibiotic resistance, and clinical workload manifesting as treatment ‘failure’.

Aim

To examine the relationship between the number of antibiotic courses prescribed to preschool children for acute respiratory tract infections (RTI), in the preceding year, and subsequent RTIs that failed to respond to antibiotic treatment (‘response failures’).

Design and setting

A cohort study using UK primary care data from the Clinical Practice Research Datalink, 2009 to 2016.

Method

Children aged 12 to 60 months (1 to 5 years) who were prescribed an antibiotic for an acute RTI (upper and lower RTI or otitis media) were included. One random index antibiotic course for RTI per child was selected. Exposure was the number of antibiotic prescriptions for acute RTI up to 12 months before the index antibiotic prescription. The outcome was ‘response failure’ up to 14 days after index antibiotic prescription, defined as: subsequent antibiotic prescription; referral; hospital admission; death; or emergency department attendance within 3 days. The authors used logistic regression models to estimate the odds between antibiotic exposure and response failure.

Results

Out of 114 329 children who were prescribed an antibiotic course for acute RTI, children who received ≥2 antibiotic courses for acute RTIs in the preceding year had greater odds of response failure; one antibiotic course: adjusted odds ratio (OR) 1.03 (95% confidence interval [CI] = 0.88 to 1.21), P = 0.67, n = 230 children; ≥2 antibiotic courses: adjusted OR 1.32 (CI = 1.04 to 1.66), P = 0.02, n = 97.

Conclusion

Childhood antibiotic exposure for acute RTI may be a good predictor for subsequent response failure (but not necessarily because of antibiotic treatment failure). Further research is needed to improve understanding of the mechanisms underlying response failure.

Modeling the effect of antibiotic exposure on the transmission of methicillin-resistant Staphylococcus aureus in hospitals with environmental contamination

In this paper both deterministic and stochastic models are developed to explore the roles that antibiotic exposure and environmental contamination play in the spread of antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), in hospitals. Uncolonized patients without or with antibiotic exposure, colonized patients without or with antibiotic exposure, uncontaminated or contaminated healthcare workers, and free-living bacteria are included in the models. Under the assumption that there is no admission of the colonized patients, the basic reproduction number R₀ is calculated. It is shown that when R₀ < 1, the infection-free equilibrium is globally asymptotically stable; when R₀ > 1, the infection is uniformly persistent. Numerical simulations and sensitivity analysis show that environmental cleaning is a critical intervention, and hospitals should use antibiotics properly and as little as possible. The rapid and efficient treatment of colonized patients, especially those with antibiotic exposure, is key in controlling MRSA infections. Screening and isolating colonized patients at admission, and improving compliance with hand hygiene are also important control strategies.

Risk Factors for Community-Acquired Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae Infections-A Retrospective Study of Symptomatic Urinary Tract Infections

Background

Community-acquired extended-spectrum beta-lactamase–producing Enterobacteriaceae (ESBL) infections are an evolving public health problem. Identifying predictive risk factors may improve patient management.

Methods

We identified 251 adult inpatients admitted to a 22-hospital system with an ESBL urinary tract infection (UTI) between 2001 and 2016. Cases were matched 1:1 with controls who had a UTI at admission with non-ESBL Enterobacteriaceae. Cases with a history of ESBL infections or hospitalization within 3 months of index admission were excluded. Univariate and multiple logistic regression were used to identify risk factors associated with ESBL UTIs.

Results

In univariate analysis, history of repeated UTIs, neurogenic bladder, urinary catheter presence at admission, and exposure to outpatient third-generation cephalosporins or fluoroquinolones within 3 months were associated with higher risk of ESBL UTIs. When controlling for severity of illness and comorbid conditions, history of repeated UTIs (adjusted odds ratio [aOR], 6.40; 95% confidence interval [CI], 3.42–12.66; P < .001), presence of urinary catheter at admission (aOR, 2.36; 95% CI, 1.15–4.98; P < .05), and prior antibiotic exposure (aOR, 7.98; 95% CI, 2.92–28.19; P < .001) remained associated with risk of ESBL infection.

Conclusions

Patients in the community with indwelling urinary catheters, history of recurrent UTIs, or recent antimicrobial use are at higher risk for de novo ESBL Enterobacteriaceae UTIs.

Training a Drug to Do New Tricks: Insights on Stability of Meropenem Administered as a Continuous Infusion

Background

The antibiotic armamentarium used to combat multi-drug resistant organisms (MDROs) include carbapenems. Continuous infusion (CI) dosing is frequently employed to maximize beta-lactam efficacy; however, use of meropenem CI has been limited due to concerns with product instability.

Objective

The primary objective of this study was to quantify meropenem serum concentrations to reflect drug stability when administered as CI over 8- or 12-h exchanges. In addition, a stability experiment was performed to further establish meropenem integrity over 12 h. The secondary objectives were to assess the ability of meropenem to achieve target pharmacokinetic/pharmacodynamic (PK/PD) exposures relative to the minimum inhibitory concentration (MIC) of the pathogen, and to determine clinical cure.

Methods

This was a retrospective, observational study on use of CI meropenem (infused either over 8- or 12- h) at a 1% concentration. The stability experiment was conducted on 1% meropenem at room temperature.

Results

In 22 patients, a median meropenem daily dose of 6 g/day (range 2-6 g/day) resulted in a median serum concentration of 17.8 mg/L (interquartile range, 9.3-27.8 mg/L). In 95% of cases, meropenem delivered as CI resulted in free drug concentrations at or above the MIC of the pathogen for the entire dosing interval. Clinical cure was achieved in 80% of patients included in this review. The stability experiment revealed negligible drug degradation at the end of the 12-h dosing interval.

Conclusions

The data from this study provides compelling evidence for the use of meropenem as CI utilizing either a 12- or 8-h exchange process.

Modeling the seasonality of Methicillin-resistant Staphylococcus aureus infections in hospitals with environmental contamination

A deterministic mathematical model with periodic antibiotic prescribing rate is constructed to study the seasonality of Methicillin-resistant Staphylococcus aureus (MRSA) infections taking antibiotic exposure and environmental contamination into consideration. The basic reproduction number R0 for the periodic model is calculated under the assumption that there are only uncolonized patients with antibiotic exposure at admission. Sensitivity analysis of R0 with respect to some essential parameters is performed. It is shown that the infection would go to extinction if the basic reproduction number is less than unity and would persist if it is greater than unity. Numerical simulations indicate that environmental cleaning is the most important intervention to control the infection, which emphasizes the effect of environmental contamination in MRSA infections. It is also important to highlight the importance of effective antimicrobial stewardship programmes, increase active screening at admission and subsequent isolation of positive cases, and treat patients quickly and efficiently.

The Effect of Antibiotic Exposure and Specimen Volume on the Detection of Bacterial Pathogens in Children With Pneumonia

Background.

Antibiotic exposure and specimen volume are known to affect pathogen detection by culture. Here we assess their effects on bacterial pathogen detection by both culture and polymerase chain reaction (PCR) in children.

Methods.

PERCH (Pneumonia Etiology Research for Child Health) is a case-control study of pneumonia in children aged 1–59 months investigating pathogens in blood, nasopharyngeal/oropharyngeal (NP/OP) swabs, and induced sputum by culture and PCR. Antibiotic exposure was ascertained by serum bioassay, and for cases, by a record of antibiotic treatment prior to specimen collection. Inoculated blood culture bottles were weighed to estimate volume.

Results.

Antibiotic exposure ranged by specimen type from 43.5% to 81.7% in 4223 cases and was detected in 2.3% of 4863 controls. Antibiotics were associated with a 45% reduction in blood culture yield and approximately 20% reduction in yield from induced sputum culture. Reduction in yield of Streptococcus pneumoniae from NP culture was approximately 30% in cases and approximately 32% in controls. Several bacteria had significant but marginal reductions (by 5%–7%) in detection by PCR in NP/OP swabs from both cases and controls, with the exception of S. pneumoniae in exposed controls, which was detected 25% less frequently compared to nonexposed controls. Bacterial detection in induced sputum by PCR decreased 7% for exposed compared to nonexposed cases. For every additional 1 mL of blood culture specimen collected, microbial yield increased 0.51% (95% confidence interval, 0.47%–0.54%), from 2% when volume was ≤1 mL to approximately 6% for ≥3 mL.

Conclusions.

Antibiotic exposure and blood culture volume affect detection of bacterial pathogens in children with pneumonia and should be accounted for in studies of etiology and in clinical management.