Risk factors for in-hospital mortality in patients with type 2 diabetes complicated by community-acquired Klebsiella pneumoniae bacteremia

Comparative epidemiology of bacteraemia in two ageing populations: Singapore and Denmark

Burden of bacteraemia is rising due to increased average life expectancy in developed countries. This study aimed to compare the epidemiology and outcomes of bacteraemia in two similarly ageing populations with different ethnicities in Singapore and Denmark. Historical cohorts from the second largest acute-care hospital in Singapore and in the hospitals of two Danish regions included patients aged 15 and above who were admitted from 1 January 2006 to 31 December 2016 with at least 1 day of hospital stay and a pathogenic organism identified. Among 13 144 and 39 073 bacteraemia patients from Singapore and Denmark, similar 30-day mortality rates (16.5%; 20.3%), length of hospital stay (median 14 (IQR: 9-28) days; 11 (6-21)), and admission rate to ICU (15.5%; 15.6%) were observed, respectively. Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus ranked among the top four in both countries. However, Singaporeans had a higher proportion of patients with diabetes (46.8%) and renal disease (29.5%) than the Danes (28.0% and 13.7%, respectively), whilst the Danes had a higher proportion of patients with chronic pulmonary disease (18.0%) and malignancy (35.3%) than Singaporeans (9.7% and 16.2%, respectively). Our study showed that top four causative organisms and clinical outcomes were similar between the two cohorts despite pre-existing comorbidities differed.

Factors Associated with Extended-Spectrum β-Lactamases and Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infections: A Five-Year Retrospective Study

Klebsiella pneumoniae is one of the leading causes of nosocomial infections. It has been estimated that nosocomial infection by Klebsiella pneumoniae comprises 3-8% of all nosocomial infections. Klebsiella pneumoniae bloodstream infections (BSIs) occur worldwide with varying mortality. Resistant strains, like those producing extended-spectrum beta-lactamases (ESBL) and carbapenemases, are becoming increasingly common, especially in hospital settings, posing therapeutic challenges. In this article, we aimed to study the epidemiology and risk factors of BSIs due to resistant Klebsiella pneumoniae strains in the period 1 January 2014-31 December 2018 at the Nicosia General Hospital, the largest tertiary hospital in Cyprus. Data on demographics, co-morbidities, prior hospitalization, prior intensive care unit (ICU) admission, previous antimicrobial use, nosocomial acquisition of the infection, the presence of a prosthetic device or surgery, and the primary site of infection were retrospectively recorded. Associations between the detection of ESBL Klebsiella pneumoniae BSIs and factors/covariates were examined using logistic regression. This study involved 175 patients with BSI caused by Klebsiella pneumoniae. Of these, 61 BSIs were caused by ESBL strains, 101 by non-ESBL, and 13 by carbapenem-resistant (CR) strains. In univariable analyses, age, sex, heart disease, antimicrobial use during current admission, previous hospitalization (ward or ICU), and primary BSI were associated with the presence of an ESBL strain. Antibiotic use during current admission and heart disease remained statistically significantly associated with ESBL Klebsiella pneumoniae BSI in multivariable models. Antibiotic use during current admission, respiratory infection, and a recent history of surgery were more prevalent among CR Klebsiella pneumoniae BSI patients than among non-CR Klebsiella pneumoniae BSI patients. Our study showed that recent antimicrobial use and heart disease were associated with BSI due to ESBL-producing Klebsiella pneumoniae. This finding could inform clinical practice in hospital settings.

Synergistic effect of Ru(II)-based type II photodynamic therapy with cefotaxime on clinical isolates of ESBL-producing Klebsiella pneumoniae

Multidrug-resistant bacteria, such as ESBL producing-Klebsiella pneumoniae, have increased substantially, encouraging the development of complementary therapies such as photodynamic inactivation (PDI). PDI uses photosensitizer (PS) compounds that kill bacteria using light to produce reactive oxygen species. We test Ru-based PS to inhibit K. pneumoniae and advance in the characterization of the mode of action. The PDI activity of PSRu-L2, and PSRu-L3, was determined by serial micro dilutions exposing K. pneumoniae to 0.612 J/cm ² of light dose. PS interaction with cefotaxime was determined on a collection of 118 clinical isolates of K. pneumoniae. To characterize the mode of action of PDI, the bacterial response to oxidative stress was measured by RT-qPCR. Also, the cytotoxicity on mammalian cells was assessed by trypan blue exclusion. Over clinical isolates, the compounds are bactericidal, at doses of 8 µg/mL PSRu-L2 and 4 µg/mL PSRu-L3, inhibit bacterial growth by 3 log₁₀ (>99.9%) with a lethality of 30 min. A remarkable synergistic effect of the PSRu-L2 and PSRu-L3 compounds with cefotaxime increased the bactericidal effect in a subpopulation of 66 ESBL-clinical isolates to > 6 log₁₀ with an FIC-value of 0.16 and 0.17, respectively. The bacterial transcription response suggests that the mode of action occurs through Type II oxidative stress. The upregulation of the extracytoplasmic virulence factors mrkD, magA, and rmpA accompanied this response. Also, the compounds show little or no toxicity in vitro on HEp-2 and HEK293T cells. Through the type II effect, PSs compounds are bactericidal, synergistic on K. pneumoniae, and have low cytotoxicity in mammals.

Elevated Mortality Risk from CRKp Associated with Comorbidities: Systematic Review and Meta-Analysis

Carbapenem-resistant Klebsiella pneumoniae has become a public health problem with therapeutic limitations and high mortality associated with comorbidities. Methods: This is a systematic review and meta-analysis with a search in PubMed, SciELO, and Lilacs. Ten articles were selected, considering cohort, case-control, and cross-sectional studies. Tests for proportions and relative risk of mortality were performed, considering a 5% threshold for significance. Statistical analyses were performe dusing Rstudio® software, version 4.0.2 of Ross Ihaka and Robert Genleman in Auckland, New Zealand. Results: Klebsiella pneumoniae, associated with chronic kidney disease, was responsible for 26%/258 deaths, chronic lung disease 28%/169, diabetes 31%/185, liver disease 15%/262, and heart disease 51%/262 deaths. Carbapenem-resistant Klebsiella pneumoniae associated with chronic kidney disease was responsible for 49%/83 deaths, with diabetes 29%/73, and with liver disease 33%/73 deaths. The risk of death from carbapenem-resistant Klebsiella pneumoniae was twice as high as the number of deaths associated with carbapenem-sensitive Klebsiella pneumoniae, RR = 2.07 (p < 0.00001). Conclusions: The present study showed an increase in mortality from carbapenem-resistant Klebsiella pneumoniae when associated with comorbidities.

Investigation of quinolone-tethered aminoguanidine as novel antibacterial agents

A recent study identified quinolone-based thiosemicarbazone with an MIC₉₀ value of 2 µM against Mycobacterium tuberculosis (Mtb). Herein, we report further optimization of the previous hit, which led to the discovery of quinolone-tethered aminoguanidine molecules with generally good antitubercular activity. Compounds 7f and 8e emerged as the hits of the series with submicromolar antitubercular activity, exhibiting MIC₉₀ values of 0.49/0.90 and 0.49/0.60 µM, respectively, in the 7H9 CAS GLU Tx medium. This shows a fivefold increase in antitubercular activity compared to the previous study. Target compounds were also screened against ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens. However, the series generally exhibited poor antibacterial activities, with only compounds 8d and 8e demonstrating >50% growth inhibition of Staphylococcus aureus and Pseudomonas aeruginosa at 32 µg/ml. The compounds displayed selective antitubercular activity as they showed no cytotoxicity effects against two noncancerous human cell lines. In silico studies predict 7f to have good solubility, no inhibitory effect on cytochrome P450 isoenzymes, and to be a non-pan-assay interfering compound.

A New Prognostic Index PDPI for the Risk of Pneumonia Among Patients With Diabetes

Objective

Risk factors for the development of pneumonia among patients with diabetes mellitus are unclear. The aim of our study was to elucidate the potential risk factors and attempt to predict the probability of pneumonia based on the history of diabetes.

Methods

We performed a population-based, prospective multicenter cohort study of 1,043 adult patients with diabetes in China during 2017–2019. Demographic information, comorbidities, or laboratory examinations were collected.

Results

The study included 417 diabetic patients with pneumonia and 626 no-pneumonia-onset diabetic patients. The predictive risk factors were chosen on the basis of a multivariate logistic regression model to predict pneumonia among patients with diabetes including male sex [odds ratio (OR) = 1.72, 95% confidence interval (CI): 1.27–2.33, p < 0.001], age ≥ 75 years (OR = 2.31, 95% CI: 1.61–3.31, p < 0.001), body mass index < 25 (OR = 2.59, 95% CI: 1.92–3.50, p < 0.001), chronic obstructive pulmonary disease (OR = 6.58, 95% CI: 2.09–20.7, p = 0.001), hypertension (OR = 4.27, 95% CI: 3.12–5.85, p < 0.001), coronary heart disease (OR = 2.98, 95% CI: 1.61–5.52, p < 0.001), renal failure (OR = 1.82, 95% CI: 1.002–3.29, p = 0.049), cancer (OR = 3.57, 95% CI: 1.80–7.06, p < 0.001), use of insulin (OR = 2.28, 95% CI: 1.60–3.25, p < 0.001), and hemoglobin A1c ≥ 9% (OR = 2.70, 95% CI: 1.89–3.85, p < 0.001). A predictive nomogram was established. This model showed c-statistics of 0.811, and sensitivity and specificity were 0.717 and 0.780, respectively, under cut-off of 125 score.

Conclusion

We designed a clinically predictive tool for assessing the risk of pneumonia among adult patients with diabetes. This tool stratifies patients into relevant risk categories and may provide a basis for individually tailored intervention for the purpose of early prevention.

Impact of wound microbiology on limb preservation in patients with diabetic foot infection

AIMS/INTRODUCTION

To investigate the association between specific bacterial pathogens and treatment outcome in patients with limb-threatening diabetic foot infection (LT-DFI).

MATERIALS AND METHODS

Consecutive patients treated for LT-DFI in a major diabetic foot center in Taiwan were analyzed between the years 2014 and 2017. Patients with positive wound culture results at first aid were enrolled. Clinical factors, laboratory data, and wound culture results were compared. Lower-extremity amputations and in-hospital mortality were defined as a poor outcome.

RESULTS

Among the 558 patients, 272 (48.7%) patients had lower extremity amputation and 22 (3.9%) patients had in-hospital mortality. Gram-negative bacterial (GNB) infection was the independent factor following factors adjustment. When all the 31 microorganisms were analyzed, only E. coli (adjusted odds ratio [aOR], 3.01; 95% CI, 1.60-5.65), Proteus spp. (aOR, 2.99; 95% CI, 1.69-5.29), and Pseudomonas aeruginosa (aOR, 2.00; 95% CI 1.20-3.32) were associated with poor outcome. The analysis of specific GNB species in association with major- or minor- amputation have been reported. No specific pathogen was associated with cause of death in patients with mortality within 30 days. The antimicrobial-resistant strains were not associated with a poor treatment outcome.

CONCLUSIONS

The presence of GNB was associated with limb amputations. This study provides insight into more timely and appropriate management of the diabetic foot infection.

In vitro susceptibility of ceftaroline against clinically important Gram-positive cocci, Haemophilus species and Klebsiella pneumoniae in Taiwan: Results from the Antimicrobial Testing Leadership and Surveillance (ATLAS) in 2012-2018

BACKGROUND/PURPOSE

Ceftaroline, with a unique activity against methicillin-resistant Staphylococcus aureus (MRSA), was not launched in Taiwan before 2019. The in vitro susceptibility data of ceftaroline against important Taiwanese pathogens are lacking.

METHODS

The in vitro susceptibility of ceftaroline against important pathogens collected from 2012 through 2018 were extracted from the Antimicrobial Testing Leadership and Surveillance program. Broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) to ceftaroline against all isolates.

RESULTS

During the study period, the in vitro data regarding isolates of S. aureus (n = 2049), Staphylococcus epidermidis (n = 185), Streptococcus pneumoniae (n = 334), Streptococcus pyogenes (n = 170), Haemophilus influenzae (n = 75), Haemophilus parainfluenzae (n = 10) and Klebsiella pneumoniae (n = 680) regardless of hospital sites of collection were analyzed. Among the S. aureus isolates studied, 19.4% showed MICs of 1 mg/L to ceftaroline, and 4.4% showed in vitro susceptible-dose dependent to ceftaroline (all MICs, 2 mg/L). Most of other Gram-positive cocci, all H. influenzae and H. parainfluenzae isolates were susceptible to ceftaroline. By contrast, about one-third (35.9%) of K. pneumoniae isolates, irrespective of infection sources, exhibited non-susceptibility to ceftaroline (MIC range, 0.015-256 mg/L; MIC50 and MIC90 values, 0.12 and 256 mg/L, respectively).

CONCLUSIONS

From the pharmacodynamic perspectives, the ceftaroline dosage of 600 mg as a 2-h intravenous infusion every 8 h is effective against all S. aureus and other Gram-positive isolates regardless of acquisition sites in Taiwan. Before ceftaroline is prescribed in treatment of the patient with Gram-negative infection, a cautious evaluation about patient's healthcare-associated factor is warranted.

Haematogenous Klebsiella pneumoniae osteomyelitis

OBJECTIVES

Klebsiella pneumoniae infection has been associated with alcoholic and diabetic patient populations, especially in Asian populations. K. pneumonia wound infection is common, but K. pneumonia without wound osteomyelitis (OM) is relatively rare. However, the pathogenesis of haematogenous K. pneumonia without open wound OM still unclear until now. In our research, we are trying to collect patients with haematogenous K. pneumonia osteomyelitis (K.p OM) at our hospital and to evaluate their contributing factors.

METHODS

We compiled a retrospective database of haematogenous K. pneumonia osteomyelitis (K.p OM) from 1990 to 2019 at our hospital. Patients' bone cultures without K. pneumonia infection were excluded. Sixteen patients with haematogenous K.p OM were recruited. Patients' basic information, comorbidities, wound history, the biochemical examination of the blood, bacterial blood, bone, urine, and liver abscess cultures, the location of OM, corresponding treatments, and post operation K.p wound infection history were reviewed retrospectively. The collected data were analyzed using SPSS software.

RESULTS

Unwounded haematogenous K.p OM had a statistically significant and positive correlation with liver insufficiency (P = .037; OR = 2.200), advanced age (≥ 65 years) (P = .037; OR = 2.200) and male gender (P = .03; OR = 1.833). DM, hypertension, steroid usage, GI or GU tract K.p infection, post operation K.p wound infection, hypoalbuminemia, and the location of K.p OM had no significant relationship to outcomes.

CONCLUSION

Male patients of advanced age (> 65 years) and patients with liver insufficiency, including liver cirrhosis and hepatitis, have a strong correlation with unwounded haematogenous K.p OM.

The mode of action of the PSIR-3 photosensitizer in the photodynamic inactivation of Klebsiella pneumoniae is by the production of type II ROS which activate RpoE-regulated extracytoplasmic factors

BACKGROUND

Due to increased bacterial multi-drug resistance (MDR), there is an antibiotic depletion to treat infectious diseases. Consequently, other promising options have emerged, such as the antimicrobial photodynamic inactivation therapy (aPDI) based on photosensitizer (PS) compounds to produce light-activated local oxidative stress (photooxidative stress). However, there are scarce studies regarding the mode of action of PS compounds to induce photooxidative stress on pathogenic γ-proteobacteria such as MDR-Klebsiella pneumoniae.

METHODOLOGY

The mode of action exerted by the cationic Ir(III)-based PS (PSIR-3) to inhibit the growth of K. pneumoniae was analyzed. RT-qPCR determined the transcriptional response induced by PSIR-3 on bacteria treated with aPDI. The expression levels of genes associated with a bacterial oxidative response, such as oxyR and sodA, and the extracytoplasmic, regulators rpoE and hfq were determined. Also, were determined the transcriptional response of the extracytoplasmic factors mrkD, acrB, magA, and rmpA.

RESULTS

At 17 μW/cm² photon flux and 4 μg/mL of the PSIR-3 compound, the K. pneumoniae growth was inhibited in 3 log₁₀. Compared with untreated bacteria, the transcriptional response induced by PSIR-3 occurs via the extracytoplasmic sigma factor rpoE and hfq. In contrast, no participation in the oxyR pathway or induction of the sodA gene was observed. This response was accompanied by the upregulation of the extracytoplasmic virulence factors mrkD, magA, and rmpA.

CONCLUSIONS

PDI aPDI produced by PSIR-3 kills K. pneumoniae and may induce damage to the bacterial envelope. The bacterium tries to avoid this injury by activation of extracytoplasmic factors mediated through the rpoE regulon.

Susceptibility of clinical isolates of meticillin-resistant Staphylococcus aureus and phenotypic non-extended-spectrum β-lactamase-producing Klebsiella pneumoniae to ceftaroline in Taiwan: Results from Antimicrobial Testing Leadership and Surveillance (ATLAS) in 2012-2018 and Surveillance of Multicentre Antimicrobial Resistance in Taiwan (SMART) in 2018-2019

Data on ceftaroline (CPT) susceptibility amongst clinical isolates of meticillin-resistant Staphylococcus aureus (MRSA, n=1284) and phenotypic non-extended-spectrum β-lactamase-producing (non-ESBL-P) Klebsiella pneumoniae (n=466), obtained from the Antimicrobial Testing Leadership and Surveillance (ATLAS) programme from 2012 to 2018, and selected MRSA isolates from patients with bloodstream infections (BSIs) (n=95) from the Surveillance of Multicentre Antimicrobial Resistance in Taiwan (SMART) programme from 2018 to 2019 were analysed. The minimum inhibitory concentrations (MICs) of ATLAS isolates were determined using the broth microdilution method, whereas the MICs of SMART BSI-MRSA isolates were determined using the Etest and MicroScan system. The pharmacokinetic profiles and pharmacodynamic parameters of CPT were applied to explore the optimal dosage against infections caused by Taiwanese MRSA and K. pneumoniae isolates. Approximately 7.1% of ATLAS MRSA isolates were susceptible-dose dependent (S-DD) to CPT, and 19.7% of the non-ESBL-P K. pneumoniae isolates were not susceptible to CPT. Amongst the ATLAS MRSA isolates, the S-DD rates to CPT amongst isolates causing lower respiratory tract infections were 11.9% and 8.5% for isolates from intensive care units (ICUs) and general wards (GWs), and those causing skin and soft tissue infections (SSTIs) were 20% and 5.3% for isolates from ICUs and GWs, respectively (P=0.015). Of the SSTI MRSA isolates from GWs, 22.7% displayed vancomycin MICs >1 mg/L. Amongst 95 SMART BSI MRSA isolates, 28 (46.7%) isolates exhibited lower CPT MICs by the Etest compared with 60 isolates with CPT MICs of 1-2 mg/L by the MicroScan system. CPT 600 mg as a 2-h intravenous infusion every 8 h is suggested for treatment of infections caused by MRSA and phenotypic non-ESBL-P K. pneumoniae in Taiwan.

Age, Pulse, Urea and Albumin (APUA) Model: A Tool for Predicting in-Hospital Mortality of Community-Acquired Pneumonia Adapted for Patients with Type 2 Diabetes

OBJECTIVE

The aim of this study was to develop a tool for predicting in-hospital mortality of community-acquired pneumonia (CAP) in patients with type 2 diabetes (T2DM).

METHODS

A retrospective study was conducted on 531 CAP patients with T2DM at The First Hospital of Qinhuangdao. The primary outcome was in-hospital mortality. Variables to develop the nomogram were selected using multiple logistic regression analysis. Discrimination was evaluated using receiver operating characteristic (ROC) curve. Calibration was evaluated using the Hosmer-Lemeshow test and calibration plot.

RESULTS

Multiple logistic regression analysis showed that age, pulse, urea and albumin (APUA) were independent risk predictors. Based on these results, we developed a nomogram (APUA model) for predicting in-hospital mortality of CAP in T2DM patients. In the training set, the area under the curve (AUC) of the APUA model was 0.814 (95% CI: 0.770-0.853), which was higher than the AUCs of albumin alone, CURB-65 and Pneumonia Severity Index (PSI) class (p<0.05). The Hosmer-Lemeshow test (χ ²=5.298, p=0.808) and calibration plot (p=0.802) showed excellent agreement between the predicted possibility and the actual observation in the APUA model. The results of the validation set were similar to those of the training set.

CONCLUSION

The APUA model is a simple and accurate tool for predicting in-hospital mortality of CAP, adapted for patients with T2DM. The predictive performance of the APUA model was better than CURB-65 and PSI class.

Occurrence and determinants of Klebsiella species bloodstream infection in the western interior of British Columbia, Canada

Background

Klebsiella species are among the most common causes of bloodstream infection (BSI). However, few studies have evaluated their epidemiology in non-selected populations. The objective was to define the incidence of, risk factors for, and outcomes from Klebsiella species BSI among residents of the western interior of British Columbia, Canada.

Methods

Population-based surveillance was conducted between April 1, 2010 and March 31, 2017.

Results

151 episodes were identified for an incidence of 12.1 per 100,000 population per year; the incidences of K. pneumoniae and K. oxytoca were 9.1 and 2.9 per 100,000 per year, respectively. Overall 24 (16%) were hospital-onset, 90 (60%) were healthcare-associated, and 37 (25%) were community-associated. The median patient age was 71.4 (interquartile range, 58.8–80.9) years and 88 (58%) cases were males. Episodes were uncommon among patients aged < 40 years old and no cases were observed among those aged < 10 years. A number of co-morbid medical illnesses were identified as significant risks and included (incidence rate ratio; 95% confidence interval) cerebrovascular accident (5.9; 3.3–9.9), renal disease 4.3; 2.5–7.0), cancer (3.8; 2.6–5.5), congestive heart failure (3.5; 1.6–6.6), dementia (2.9; 1.5–5.2), diabetes mellitus (2.6; 1.7–3.9), and chronic obstructive pulmonary disease (2.3; 1.5–3.5). Of the 141 (93%) patients admitted to hospital, the median hospital length stay was 8 days (interquartile range, 4–17). The in-hospital and 30-day all cause case-fatality rates were 24/141 (17%) and 27/151 (18%), respectively.

Conclusions

Klebsiella species BSI is associated with a significant burden of illness particularly among those with chronic co-morbid illnesses.

Photodynamic treatment for multidrug-resistant Gram-negative bacteria: Perspectives for the treatment of Klebsiella pneumoniae infections

The emergence of multi-drug resistance for pathogenic bacteria is one of the most pressing global threats to human health in the 21st century. Hence, the availability of new treatment becomes indispensable to prevent morbidity and mortality caused by infectious agents. This article reviews the antimicrobial properties of photodynamic therapy (PDT), which is based on the use of photosensitizers compounds (PSs). The PSs are non-toxic small molecules, which induce oxidative stress only under excitation with light. Then, the PDT has the advantage to be locally activated using phototherapy devices. We focus on PDT for the Klebsiella pneumoniae, as an example of Gram-negative bacteria, due to its relevance as an agent of health-associated infections (HAI) and a multi-drug resistant bacteria. K. pneumoniae is a fermentative bacillus, member of the Enterobacteriaceae family, which is most commonly associated with producing infection of the urinary tract (UTI) and pneumonia. K. pneumoniae infections may occur in deep organs such as bladder or lungs tissues; therefore, activating light must get access or penetrate tissues with sufficient power to produce effective PDT. Consequently, the rationale for selecting the most appropriate PSs, as well as photodynamic devices and photon fluence doses, were reviewed. Also, the mechanisms by which PDT activates the immune system and its importance to eradicate the infection successfully, are discussed.

Antimicrobial resistance and risk factors for mortality of pneumonia caused by Klebsiella pneumoniae among diabetics: a retrospective study conducted in Shanghai, China

Purpose: To investigate antimicrobial resistance and risk factors for mortality of Klebsiella pneumoniae (KP) pneumonia in diabetics and nondiabetics. Patients and methods: A retrospective study was conducted among inpatients of KP pneumonia via electronic medical records in a territory hospital between January 2016 and June 2018. Antimicrobial resistance in KP pneumonia was compared between diabetics and nondiabetics. Independent risk factors for mortality in KP pneumonia were identified by univariate and multivariate logistic regression among diabetics and nondiabetics separately. Results: In this study, 456 patients with KP pneumonia were included. There were 156 cases with diabetes and 300 without diabetes. KP showed a lower antimicrobial resistance to a multitude of antimicrobials in pneumonia among diabetics than nondiabetics, namely aztreonam, cefotetan, sulperazone, meropenem, amikacin, tobramycin, sulfamethoxazole, and fosfomycin. In addition, carbapenem-resistant Klebsiella pneumoniae (CRKP) was more prevalent among nondiabetics than diabetics who were admitted to intensive care unit (ICU) (63.0% vs 45.1%, P = 0.038). Multivariable analysis showed that independent risk factors for in-hospital mortality (IHM) in KP pneumonia among diabetics differed from that among nondiabetics as well. Independent predictors for IHM of KP pneumonia among diabetics were male (OR: 5.89, 95% CI: 1.34-25.93, P = 0.019), albumin (ALB) < 35 g/L (OR: 7.00, 95% CI: 2.02-24.28, P = 0.002), bloodstream infection (BSI) (OR: 21.14, 95% CI: 3.18-140.72, P = 0.002), and invasive ventilation during hospitalization (OR: 8.00, 95% CI: 2.99-21.42, P < 0.001). In nondiabetics, independent predictors were higher CURB-65 score (OR: 1.92, 95% CI: 1.29-2.86, P = 0.001), CRKP (OR: 2.72, 95% CI: 1.07-6.90, P = 0.035), BSI (OR: 4.98, 95% CI: 1.34-18.50, P = 0.017), and ICU admission (OR: 4.06, 95% CI: 1.57-10.47, P = 0.004). Conclusion: In KP pneumonia, diabetics showed lower antimicrobial resistance and different independent risk factors for mortality compared with nondiabetics, in line with previous studies. Importantly, further attention should be paid on rational and effective antibiotic and supportive treatments in order to reduce mortality without aggravating antimicrobial resistance and metabolic damage among diabetics.

Antimicrobial resistance and outcomes of community-onset bacterial bloodstream infections in patients with type 2 diabetes

OBJECTIVES

Antimicrobial resistance of bacterial pathogens in the diabetic population with infection is seldom investigated. This study evaluated the antimicrobial resistance and outcomes of community-onset bloodstream infections (CO-BSIs) in patients with diabetes.

METHODS

From 2007-2014, 1271 monomicrobial CO-BSIs and 178 polymicrobial CO-BSIs were identified in patients with type 2 diabetes from three teaching hospitals in Taiwan. Antimicrobial-resistant strains of the ten most prevalent bacterial pathogens in monomicrobial CO-BSIs were recorded and were defined according to individual drug resistance. The 30-day mortality rate and factors associated with outcome were analysed.

RESULTS

Antimicrobial-resistant strains were found in 33.7% (379/1125) of monomicrobial CO-BSIs involving the 10 most prevalent pathogens. The leading pathogens in these monomicrobial CO-BSIs were Staphylococcus spp. (33.8%; 430/1271), Escherichia coli (20.9%; 266/1271) and Klebsiella spp. (9.6%; 122/1271); antimicrobial-resistant strains accounted for 61.9%, 18.4% and 10.7% of each, respectively. A higher overall 30-day mortality rate was observed for patients infected by antimicrobial-resistant strains compared with antimicrobial-susceptible strains (9.5% vs. 5.5%; P=0.011, log-rank test). A lower serum albumin level was a predictor of mortality after adjusting for antimicrobial-resistant strains and C-reactive protein level.

CONCLUSIONS

Antimicrobial-resistant bacterial pathogens pose a serious threat to diabetic patients with CO-BSIs owing to a higher risk of mortality.

Clinical predictors and outcomes of Klebsiella pneumoniae bacteraemia in a regional hospital in Hong Kong

BACKGROUND

Klebsiella pneumoniae (KP) infection is associated with high morbidity and mortality. Multidrug resistance, especially extended-spectrum β-lactamase (ESBL) production, in KP is endemic worldwide.

AIM

To evaluate the clinical characteristics and outcomes of patients with KP bacteraemia in critical care and general ward settings.

METHODS

Adult patients admitted to a regional hospital in Hong Kong from January 1^st, 2009 to June 30^th, 2016 (7.5 years) with KP bacteraemia were included. Demographics, clinical features, microbiological characteristics, and outcomes were analysed.

FINDINGS

Among 853 patients, 178 (20.9%) required critical care and 176 (20.6%) died within 30 days of hospital admission. Thirty-day survivors were younger (P<0.001), had milder disease (defined by Sequential Organ Failure Assessment score) (P<0.001), presented with hepatobiliary sepsis (P<0.001) or urosepsis (P<0.001), less septic shock (P=0.013), fewer invasive organ supports (P<0.001), and had appropriate empirical antibiotics (P<0.001). Cox regression analysis showed that respiratory tract infection (hazard ratio: 2.99; 95% confidence interval: 2.061-4.337; P≤0.001), gastrointestinal tract infection (excluding hepatobiliary system) (2.763; 1.761-4.337; P≤0.001), mechanical ventilation (2.202; 1.506-3.221; P≤0.001), medical case (1.830; 1.253-2.672; P=0.002), inappropriate empirical antibiotics (1.716; 1.267-2.324; P≤0.001), female (1.699; 1.251-2.307; P<0.001), age >65 years (1.692; 1.160-2.467; P=0.006), and presence of solid tumour (1.457; 1.056-2.009; P=0.022) were independent risk factors for 30-day mortality. Unexpectedly, diabetes mellitus was associated with better 30-day survival (P=0.002). A total of 102 patients (12.0%) had infections with ESBL-producing strains, which were not associated with higher 30-day mortality.

CONCLUSION

KP bacteraemia is associated with high 30-day mortality. Site of infection, patients' comorbidities and appropriate use of empirical antibiotic are important predictors of patients' outcomes.

Synthesis and biological evaluation of indole core-based derivatives with potent antibacterial activity against resistant bacterial pathogens

The emergence of drug resistance in bacterial pathogens is a growing clinical problem that poses difficult challenges in patient management. To exacerbate this problem, there is currently a serious lack of antibacterial agents that are designed to target extremely drug-resistant bacterial strains. Here we describe the design, synthesis and antibacterial testing of a series of 40 novel indole core derivatives, which are predicated by molecular modeling to be potential glycosyltransferase inhibitors. Twenty of these derivatives were found to show in vitro inhibition of Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus. Four of these strains showed additional activity against Gram-negative bacteria, including extended-spectrum beta-lactamase producing Enterobacteriaceae, imipenem-resistant Klebsiella pneumoniae and multidrug-resistant Acinetobacter baumanii, and against Mycobacterium tuberculosis H37Ra. These four compounds are candidates for developing into broad-spectrum anti-infective agents.