Microbiologic characteristics and predictors of mortality in bloodstream infections in intensive care unit patients: A 1-year, large, prospective surveillance study in 5 Italian hospitals

Comparison of bloodstream and non-bloodstream infections caused by carbapenem-resistant Klebsiella pneumoniae in the intensive care unit: a 9-year respective study

Background

Bloodstream infections (BSIs) caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) have received much attention. However, few studies have identified risk factors for CRKP BSIs in comparison to CRKP non-bloodstream infections (non-BSIs). This study aimed to compare the epidemiology, risk factors, and outcomes of CRKP BSIs and CRKP non-BSIs.

Methods

We conducted a retrospective study of patients infected with CRKP in the ICU from January 2012 to December 2020. Clinical characteristics and outcomes were compared between CRKP BSIs and CRKP non-BSIs. Predictors associated with 28-day all-cause mortality in CRKP-infected patients were also evaluated.

Results

326 patients infected with CRKP were enrolled, including 96 patients with CRKP BSIs and 230 with CRKP non-BSIs. The rates of CRKP BSIs in CRKP infections were generally raised from 2012 (12.50%) to 2020 (45.76%). Multivariate logistic analysis indicated that the use of carbapenems within the prior 90 days was an independent risk factor for CRKP BSIs (p = 0.019). Compared to CRKP non-BSIs, CRKP isolates in the CRKP BSI group were found to be non-susceptible to more tested carbapenems (p = 0.001). Moreover, the CRKP BSI group exhibited a higher mortality rate (p = 0.036). The non-susceptibility of CRKP isolates to more tested carbapenems (p = 0.025), a high SOFA score (p = 0.000), and the use of antifungal drugs within the prior 90 days (p = 0.018) were significant factors for 28-day all-cause mortality in CRKP-infected patients.

Conclusion

The proportion of CRKP BSI increased progressively in CRKP-infected patients over 9 years. The use of carbapenems within the prior 90 days was an independent risk factor for the development of CRKP BSIs. The non-susceptibility of CRKP isolates to more tested carbapenems and a higher mortality rate were found in the CRKP BSI group.

Clinical characteristics and prognosis of pneumonia-related bloodstream infections in the intensive care unit: a single-center retrospective study

Background

Bloodstream infections (BSI) are one of the most severe healthcare-associated infections in intensive care units (ICU). However, there are few studies on pneumonia-related BSI (PRBSI) in the ICU. This study aimed to investigate the clinical and prognostic characteristics of patients with PRBSI in the ICU and to provide a clinical basis for early clinical identification.

Methods

We retrospectively collected data from patients with bacterial BSI in a single-center ICU between January 1, 2017, and August 31, 2020. Clinical diagnosis combined with whole-genome sequencing (WGS) was used to clarify the diagnosis of PRBSI, and patients with PRBSI and non-PRBSI were analyzed for clinical features, prognosis, imaging presentation, and distribution of pathogenic microorganisms.

Results

Of the 2,240 patients admitted to the MICU, 120 with bacterial BSI were included in this study. Thirty-two (26.7%) patients were identified as having PRBSI based on the clinical diagnosis combined with WGS. Compared to patients without PRBSI, those with PRBSI had higher 28-day mortality (81.3 vs.51.1%, p = 0.003), a higher total mortality rate (93.8 vs. 64.8%, p = 0.002), longer duration of invasive mechanical ventilation (median 16 vs. 6 days, p = 0.037), and prolonged duration of ICU stay (median 21 vs. 10 days, p = 0.004). There were no differences in other baseline data between the two groups, but patients with PRBSI had extensive consolidation on chest radiographs and significantly higher Radiographic Assessment of Lung Edema scores (mean 35 vs. 24, p < 0.001). The most common causative organisms isolated in the PRBSI group were gram-negative bacteria (n = 31, 96.9%), with carbapenem-resistant gram-negative bacteria accounting for 68.8% (n = 22) and multidrug-resistant bacteria accounting for 81.3% (n = 26).

Conclusion

Pneumonia-related BSI is an important component of ICU-BSI and has a poor prognosis. Compared to non-PRBSI, patients with PRBSI do not have typical clinical features but have more severe lung consolidation lesions, and should be alerted to the possibility of their occurrence when combined with pulmonary gram-negative bacterial infections, especially carbapenem-resistant bacteria. Further multicenter, large-sample studies are needed to identify the risk factors for the development of PRBSI and prevention and treatment strategies.

Epidemiology of Bloodstream Infections and Antimicrobial Susceptibility Pattern in ICU and Non-ICU Wards: A Four-Year Retrospective Study in Isfahan, Iran

Background

Bloodstream infections (BSIs) are one of the causes of morbidity and mortality in hospitalised patients. This study evaluated BSI's incidence, trend, antimicrobial susceptibility patterns and mortality in AL Zahra Hospital in Isfahan, Iran.

Materials and Methods

This retrospective study was conducted in AL Zahra Hospital from March 2017 to March 2021. The Iranian nosocomial infection surveillance system was used for data gathering. The data included demographic and hospital data, type of bacteria, and antibiotic susceptibility findings and were analysed in SPSS-18 software.

Results

The incidence of BSIs was 1.67% and 0.47%, and the mortality was 30% and 15.2% in the intensive care unit (ICU) and non-ICU wards, respectively. In the ICU, the mortality was correlated with the use of the catheter, type of organism and year of study, but in non-ICU, correlated with age, gender, use of the catheter, ward, year of study and duration between the incidence of BSIs and discharging/death. Staphylococcus epidermidis, Acinetobacter spp. and Klebsiella spp. were the most frequent germs isolated in all wards. Vancomycin (63.6%) and Gentamycin (37.7%) for ICU and Vancomycin (55.6%) and Meropenem (53.3) for other wards were the most sensitive antibiotics.

Conclusion

Despite the few rate of BSI in the last four years in AL Zahra Hospital, our data showed that its incidence and mortality in the ICU ward are significantly more than in other hospital wards. We recommend prospective multicentre studies to know the total incidence of BSI, local risk factors and patterns of pathogens causing BSI.

Clinical characteristics, risk factors and outcomes of Klebsiella pneumoniae pneumonia developing secondary Klebsiella pneumoniae bloodstream infection

Purpose

The clinical characteristics of Klebsiella pneumoniae (KP) pneumonia and KP bloodstream infection (KP-BSI) are often reported, while the risk factors for KP pneumonia developing into secondary KP-BSI (KP-pneumonia/KP-BSI) are largely unknown. Therefore, this study attempted to investigate the clinical characteristics, risk factors and outcomes of KP-pneumonia/KP-BSI.

Methods

A retrospective observational study was conducted at a tertiary hospital between January 1, 2018, and December 31, 2020. The patients were divided into groups of KP pneumonia alone and KP pneumonia/KP-BSI, and the clinical information were collected from medical records electronic system.

Results

A total of 409 patients were finally recruited. According to the multivariate logistic regression analysis, male sex (adjusted odds ratio [aOR] 3.7; 95% CI, 1.44–9.5), immunosuppression (aOR, 13.52; 95% CI, 2.53,72.22), APACHE II score higher than 21 (aOR, 3.39; 95% CI, 1.41–8.12), serum procalcitonin (PCT) levels above 1.8 ng/ml (aOR, 6.37; 95% CI, 2.67–15.27), ICU stay of more than 2.5 days before pneumonia onset (aOR, 1.09; 95% CI, 1.02,1.17), mechanical ventilation (aOR, 4.96; 95% CI, 1.2,20.5), Klebsiella pneumoniae isolates producing extended spectrum β-lactamase (ESBL-positive KP) (aOR, 12.93; 95% CI, 5.26–31.76), and inappropriate antibacterial therapy (aOR, 12.38; 95% CI, 5.36–28.58) were independent factors of KP pneumonia/KP BSI. In comparison with the patients with KP pneumonia alone, the patients with KP pneumonia/KP BSI showed an almost 3 times higher incidence of septic shock (64.4% vs. 20.1%, p < 0.01), a longer duration of mechanical ventilation, and longer lengths of ICU stay and total hospital stay (median days, 15 vs. 4,19 vs. 6, 34 vs. 17, respectively, both p < 0.01). Additionally, the overall in-hospital crude mortality rate in the patients with KP-pneumonia/KP-BSI was more than two times higher than that in those with KP pneumonia alone (61.5% vs. 27.4%, p < 0.01).

Conclusion

Factors including male sex, immunosuppression, APACHE II score higher than 21, serum PCT levels above 1.8 ng/ml, ICU stay of more than 2.5 days before pneumonia onset, mechanical ventilation, ESBL-positive KP, and inappropriate antibacterial therapy are independent risk factors for KP pneumonia/KP-BSI. Of note, the outcomes in patients with KP pneumonia worsen once they develop secondary KP-BSI, which merits more attention.

Occurrence and Genomic Characteristics of Hypervirulent Klebsiella pneumoniae in a Tertiary Care Hospital, Eastern India

Purpose

This study was conducted to find out the occurrence of hypervirulent Klebsiella pneumoniae (hvKP) isolates from different clinical specimens in a tertiary care hospital of eastern India and investigate the distribution of virulence factors, capsular serotypes and antibiogram profile. The distribution of carbapenemase-encoding genes in convergent (hvKP and carbapenem-resistant) isolates was also studied.

Materials and methods

A total of 1004 K. pneumoniae isolates were obtained from different clinical specimens from August 2019 to June 2021 and hvKP isolates were identified using the string test. Genes of capsular serotypes K1, K2, K5, K20, K54 and K57, virulence-associated genes, rmpA, rmpA2, mrkD, allS, iroN, iutA, iuc, kfuB and ybtS, and carbapenemase-encoding genes, NDM-1, OXA-48, OXA-181, and KPC, were evaluated by polymerase chain reaction. Antimicrobial susceptibility was determined primarily by the VITEK-2 Compact automated platform (bioMérieux, Marcy-l'Étoile, France) and supplemented by disc-diffusion/EzyMIC (HiMedia, Mumbai, India) wherever needed.

Results

Out of 1004 isolates, 33 (3.3%) were hvKP. Most frequent capsular serotype was K2 in 11 (33.3%). Amongst virulence genes, mrkD, iutA and kfuB were detected most frequently in 93.9%, 84.8% and 63.6% isolates respectively. Classical Klebsiella pneumoniae isolates were significantly more resistant than hvKP to cephalosporins, amoxicillin-clavulanic acid, and fluoroquinolones (p < 0.05). Carbapenem resistance was seen in 10 hvKP convergent isolates with the most prevalent carbapenemase-encoding gene being OXA-48 and OXA-181 in 50% isolates.

Conclusion

There is a need for continued surveillance of hvKP strains in view of the impending threat of a global spread of convergent strains.

Risk factors and mortality of carbapenem-resistant Klebsiella pneumoniae bloodstream infection in a tertiary-care hospital in China: an eight-year retrospective study

BACKGROUND

The prevalence of carbapenem-resistant Klebsiella pneumoniae bloodstream infection (CRKP-BSI) is increasing worldwide. CRKP-BSI is associated with high rates of morbidity and mortality due to limited antibiotic choices. Here, we aim to identify the prevalence and risk factors for infection and mortality of CRKP BSI.

METHODS

This was a retrospective study of the past data from January 1st, 2012 to December 31st, 2019 of adult patients with KP-BSI in Xiangya Hospital, China.

RESULTS

Among the 706 incidences included in this study, 27.4% of them (212/753) being CR-KP strains. The occurrence of CRKP-BSI was increased from 20.69 to 37.40% from 2012 to 2019. Hematologic malignancies and ICU acquired infection were identified to be substantial risk factors of carbapenem resistance. The overall 28-day mortality rates of CRKP-BSI patients was significantly higher than that of CSKP-BSI (P < 0.001). Logistic regression analysis identified severe sepsis or septic shock incidents, inadequate empirical antimicrobial therapy and corticosteroids use preceding infection onset as the independent predictors of 28-day mortality of CRKP-BSI patients. However, high dose carbapenem combination therapy was identified as anticipated factors of low 28-day mortality.

CONCLUSION

The occurrence of CRKP-BSI was significantly increased during the study period. Hematologic malignancies and ICU acquired infection were associated with the development of CRKP BSI. Severe sepsis or septic shock incidents, inadequate empirical antimicrobial therapy and corticosteroids use preceding infection onset caused significant increase of mortality rates in CRKP-BSI patients. High dose carbapenem combination therapy was associated with better outcome.

Molecular Epidemiology and Risk Factors of Carbapenem-Resistant Klebsiella Pneumoniae Bloodstream Infections in Wuhan, China

OBJECTIVE

The clinical characteristics and microbiological data of patients with K. pneumoniae bloodstream infections (BSI) from January 2018 to December 2020 were retrospectively analyzed to study the molecular epidemiology of Carbapenem-resistant Klebsiella pneumoniae (CRKP). We also aimed to identify the risk factors for the development of CRKP BSI.

METHODS

This retrospective study was conducted at Renmin Hospital of Wuhan University from January 2018 to December 2020. The date of non-duplicate K. pneumoniae isolates isolated from blood samples was identified using the microbiology laboratory database. The data from patients diagnosed with K. pneumoniae BSI were collected and analyzed.

RESULTS

From 2018 to 2020, there were 510 non-duplicated K. pneumoniae blood isolates, mainly distributed in the intensive care unit (ICU) (28.4%), that were identified in our research. These cases included 77 strains of CRKP and 433 strains of carbapenem-susceptible K. pneumoniae (CSKP). The resistance rate of K. pneumoniae to meropenem and imipenem increased from 11.2% in 2018 to 27.1% in 2020. Moreover, Compared with CSKP, all CRKP isolates showed multi-resistance to tested antibiotics. The phylogenetic analysis showed that the CRKP isolates could be grouped into four major clades, and multilocus sequence typing revealed that the isolates had considerable clonality. Overall, 8 sequence types (STs) of CRKP were detected, of which ST11 comprised the majority and clustered into clade 3. The most prevalent carbapenemase gene was bla_KPC (87%) among the CRKP isolates, followed by bla_NDM (9.1%) and bla_IMP (1.3%). A total of 74 (16.6%) patients with CRKP BSI and 373 (83.4%) patients with CSKP BSI were categorized as the case and control groups. The mortality in the CRKP group was 44.6%, and 11.5% in CSKP group (P<0.001). A multivariate analysis that a long hospital stay before BSI (OR=1.42, 95% CI 1.02-4.31, P=0.011), ICU hospitalization history (OR=3.30, 95% CI 1.35-8.05, P=0.002), and prior use of carbapenems (OR=3.33, 95% CI 1.29-7.27, P=0.001) and antifungals (OR=2.81, 95% CI 1.24-6.04, P<0.001) were independent risk factors for CRKP BSI.

CONCLUSION

ST11 is the predominant type of CRKP mediating inter-hospital transmission, and bla_KPC is the main carbapenemase gene harboured by CRKP blood isolates. ICU stay, prolonged hospitalization before BSI, and prior use of carbapenems and antifungals were independent risk factors for acquiring CRKP BSI. Our study may provide insights into early infection control practices.

Clinical Characteristics, Risk Factors, and Outcomes of Patients with Polymicrobial Klebsiella pneumoniae Bloodstream Infections

Background

Polymicrobial Klebsiella pneumoniae bloodstream infection (KP-BSI) has been reported to account for more than 10% of all KP-BSI, but few studies have characterized polymicrobial KP-BSI. Our study investigated the clinical characteristics, risk factors, and outcomes of polymicrobial KP-BSI by comparing with monomicrobial KP-BSI.

Methods

We conducted a single-center retrospective cohort study of patients with KP-BSI from 1 January 2013 to 31 December 2018 and collected the clinical data by reviewing electronic medical records.

Results

Of the 818 patients with KP-BSI recruited, 13.9% (114/818) were polymicrobial KP-BSI. The severity of illness in polymicrobial and monomicrobial KP-BSI was similar, while the rate of resistance to carbapenems was obviously higher in polymicrobial KP-BSI (78.1% vs. 65.6%, p = 0.009). On multivariate analysis, hospitalization in burn ward (odds ratio (OR) 6.13, 95% confidence interval (CI) 2.00-18.76, p = 0.001) and intensive care unit (OR 2.39, 95% CI 1.05-5.43, p = 0.038) was independently associated with polymicrobial KP-BSI. Gram-negative bacteria accounted for the highest proportion (68.9%) among copathogens of polymicrobial KP-BSI, whereas gram-positive bacteria (22.9%) and Candida (8.2%) ranked the second and the third, respectively, with Acinetobacter baumannii being the most common (23.0%). Patients with polymicrobial KP-BSI had longer hospital days after BSI onset and total hospital days than patients with monomicrobial KP-BSI (median (interquartile range (IQR)), 19 (5, 39) vs. 12 (6, 25), 37 (21, 67) vs. 29 (16, 53), respectively, p < 0.05). The mortality did not differ between polymicrobial KP-BSI and monomicrobial KP-BSI (all p > 0.05).

Conclusions

It was observed that polymicrobial KP-BSI accounted for a significant proportion among all KP-BSI in the current study. Hospitalization in burn ward and intensive care unit was an independent risk factor for the development of polymicrobial KP-BSI. The patients with polymicrobial KP-BSI had a higher rate of carbapenem-resistant K. pneumoniae and might have poor outcomes compared to monomicrobial KP-BSI.

Early- and Late-Onset Bloodstream Infections in the Intensive Care Unit: A Retrospective 5-Year Study of Patients at a University Hospital in China

BACKGROUND

Limited data are available regarding the current microbiological characteristics of bloodstream infections (BSIs) in intensive care units (ICUs) in China. This retrospective study aimed to determine the epidemiology of early- and late-onset BSIs in our ICU.

METHODS

We retrospectively collected data about ICU patients with BSI from 2013 to 2017. The patients were divided into the early- and late-onset BSI groups according to if BSI occurred within or beyond 48 hours after ICU admission. Univariate and multivariate logistic regression analyses were used to assess the risk factors for infection with multidrug resistant organisms (MDROs).

RESULTS

Of 5474 ICU admissions, 486 (8.9%) patients with BSIs and with 500 microorganisms were included in this study, 246 (50.6%) of whom had early-onset BSIs. Two hundred and seventy patients were infected with MDROs. The proportion of MDRO infections was significantly higher among patients with late-onset BSIs than among those with early-onset BSIs (57.9% vs. 41.5%, P = .017). The ICU mortality rate was significantly higher in the late-onset BSI group (44.6% vs. 33.8%, P = .014) and early and appropriate antimicrobial treatment significantly improved the survival rate among patients with BSI (P < .001).

CONCLUSIONS

MDROs affected more than half of patients with BSI in the ICU. Early appropriate empirical antimicrobial therapy could improve clinical outcome of patients with BSIs.

A Retrospective Analysis of Risk Factors and Outcomes of Carbapenem-Resistant Klebsiella pneumoniae Bacteremia in Nontransplant Patients

BACKGROUND

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a major problem among nosocomial infections, and it is a serious threat to patients. The clinical characteristics and outcome of CRKP bloodstream infection (BSI) in nontransplant patients remains unelucidated. The aim of this study was as follows: identify the risk factors of CRKP infection; generate new ideas for prevention; and generate new ideas for the most effective therapeutic management in nontransplant patients.

METHODS

The study retrospectively analyzed the clinical and microbiological data of nontransplant patients with K pneumoniae (KP) bacteremia from January 2013 to December 2015 to identify risk factors, clinical features, and outcomes using multivariate logistic regression analysis.

RESULTS

Of the 371 patients with KP-BSI in nontransplant patients included in this study, 28.0% (N = 104) had CRKP. The 28-day mortality was higher in patients infected with CRKP (55.8%) than in those with carbapenem-susceptible KP (13.9%) (P < .001). Multivariate analysis showed previous gastric catheterization, previous use of carbapenems, hypoproteinemia, and high Acute Physiologic Assessment and Chronic Health Evaluation II scores as independent risk factors for CRKP-BSIs. Carbapenem-resistant KP infection, severe illness, and tigecycline therapy were independent risk factors for death from KP-BSIs. Taken together, inappropriate antibiotic treatment both in empirical and definitive therapy and imipenem minimum inhibitory concentrations (MICs) of >8 mg/L were associated with poor clinical outcome.

CONCLUSIONS

Nontransplant patients with CRKP-BSI had higher mortality. Carbapenems exposure was an independent risk factor for CRKP infection. Imipenem MICs of >8 mg/L, tigecycline therapy, and inappropriate treatments increased the 28-day mortality of KP-BSI patients.

Incidence, Risk Factors and Clinical Outcomes of Patients with Hypermucoviscoid Klebsiella in a Tertiary Intensive Care Unit

Background and Objectives:

Hypermucoviscoid Klebsiella(hvKP), a dreaded variant of Klebsiella, so far, fewer cases were reported from the community. This study was designed to evaluate the incidence of hvKP isolates, risk factors for hvKP infections, antibiotic sensitivity pattern and clinical outcome including morbidity and mortality.

Patients and Setting:

Patients who have got admitted under medical intensive care unit (MICU) and had positive culture of Klebsiella infections.

Materials and Methods:

This study was conducted at department of MICU at a tertiary care hospital between January 2018 and December 2018. A standardized proforma was prepared and data was collected, which includes basic demographics of the patients, co-morbidities, clinical details and mortality. This study was approved by the Institutional Review Board and Ethics Committee.

Results:

A total of 165 patients (males, 123; 74.5%) had Klebsiella pneumoniae infection during the study period, out of whom 32 was hvKP (19.4%). The mean age was 53.1 ± 16.8 years. Among the 32 hvKP patients, 22 (68.8%) were hospital acquired infection (HAI) and 10 were (31.2%) community acquired infection. The overall mortality rate of hvKP infection was 56.2% (18/32). The incidence of mortality rate was similar in patients having pan-drug sensitive and in patients with extreme drug-resistance (61.9% vs. 66.7%; P = 0.831). HAI is significantly associated with multi drug resistance of hvKP (odds ratio [OR], 7.917; P < 0.05) and diabetes is associated with increased risk of hvKP related mortality (OR, 5.250; P = 0.054).

Conclusions:

Our study results showed, increased incidence of HAI with hvKP predominantly associated with pneumonia and increase in trend of drug resistance with two cases being pan resistant. More number of studies are required to evaluate the existing antibiotics strategy and steps to curb the spread of this dreaded infection.

Five-year change of prevalence and risk factors for infection and mortality of carbapenem-resistant Klebsiella pneumoniae bloodstream infection in a tertiary hospital in North China

BACKGROUND

There are few studies focused on carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infection (BSI). The aim of this study is to identify the prevalence and risk factors for infection and mortality of CRKP BSI.

METHODS

Susceptibility of Klebsiella pneumoniae (KP) isolated from blood samples and the proportion of CRKP were recorded annually. One hundred sixty-four patients with CRKP and 328 with carbapenem-susceptible Klebsiella pneumoniae (CSKP) BSI were categorized as the case group and control group to identify risk factors for CRKP infection and mortality by univariable analysis and multivariable logistic-regression analysis.

RESULTS

The proportion and mortality of CRKP BSI increased significantly, with the percentage of KP in BSI increasing from 7 to 12% from 2014 to 2019 with a concomitant resistance to meropenem increasing from 16.7 to 41.8%. Compared with CSKP group, patients in CRKP group had longer hospitalization time before bacteremia (median 14 vs 4, P < 0.001) and longer total hospitalization time (median 31 vs 19, P < 0.001). The proportion of admission to ICU was higher (70.7% vs 17.7%, P < 0.001), and APACHE II score was higher (median 12 vs 8, P < 0.001). The mortality in CRKP group was 43.9% (72/164), while 14.9% (49/328) in CSKP group (p < 0.001). KP detection in other sites(P = 0.036, OR 1.964), blood purification(P = 0.018, OR 3.326), bronchoscopy(P = 0.011, OR 5.423), surgery (P = 0.001, OR 3.084), carbapenem use(P = 0.001, OR 3.395), tigecycline use(P = 0.006, OR 4.595) were independent risk factors for CRKP BSI. Previous hospitalization (P = 0.048, OR 2.755), long hospitalization (P = 0.003, OR 1.035), bone marrow puncture (P = 0.037, OR3.856), use of β-lactamase inhibitor (P = 0.005, OR 3.890) were independent risk factors for mortality in CRKP BSI.

CONCLUSION

The prevalence and mortality of CRKP BSI are still increasing. Timely treatment of KP infection in other site, strengthening the hospital infection control of blood purification, bronchoscopy and surgery, control the use of carbapenem and tigecycline, may help to prevent CRKP BSI. More preventative hospital resources are needed for severely ill patients with prolonged hospitalizations and intensive care.

Organ donor screening for carbapenem-resistant gram-negative bacteria in Italian intensive care units: the DRIn study

The 759 cases of brain death declaration (BDD [Italian law, 6 hours of observation time]) that occurred in 190 Italian intensive care units (ICUs) between May and September 2012 were studied to quantify carbapenem-resistant gram-negative bacteria (CR-GN) isolated in organ donors, to evaluate adherence to national screening guidelines, and to identify risk factors for CR-GN isolation. Mandatory blood, bronchoalveolar lavage, and urine cultures were performed on the BDD day in 99% of used donors. Because results were rarely made available before transplant, >20% of transplants were performed before obtaining any microbiological information, and organs from 15 of 22 CR-GN cases were used. Two (lung-liver) of the 37 recipients died, likely because of donor-derived early CR-GN sepsis. ICU stay >3 days (odds ratio [OR] = 7.49, P = .004), fever (OR = 3.11, P = .04), age <60 years (OR = 2.80, P = .06), and positive ICU epidemiology (OR = 8.77, P = .07) were associated with CR-GN isolation. An association between single ICU and risk of CR-GN was observed, as a result of differences across ICUs (ICC = 29%; 95% confidence interval [CI] 6.5%-72%) probably related to inadequate practices of infection control. Continuous education aimed at implementing priority actions, including stewardship programs for a rational use of antimicrobials, is a priority in healthcare systems and transplant networks. Improved awareness among ICU personnel regarding the importance of early CR-GN detection and timely alert systems might facilitate decisions regarding organ suitability and eventually save recipient lives.

Risk Factors for Carbapenem-resistant Klebsiella pneumoniae Infection and Mortality of Klebsiella pneumoniae Infection

Background:

Klebsiella pneumoniae (KP) is a pathogen commonly causing nosocomial infection. Carbapenem-resistant KP (CRKP) is more resistant to multiple antimicrobial drugs than carbapenem-susceptible KP (CSKP) isolates. The aim of the present study was to identify the risk factors for CRKP infection and the predictors of mortality among KP-infected adult patients.

Methods:

Patients with CRKP and CSKP infection were categorized as the case group and control group, respectively, and we conducted a 1:1 ratio case-control study on these groups. The CRKP isolates collected were tested for antimicrobial susceptibility and presence of KP carbapenemase (KPC) gene. Clinical data were collected to identify risk factors for CRKP infection and mortality of KP infection. Risk factors were analyzed under univariable and multivariable logistic regression model.

Results:

The independent risk factors for CRKP infection were admission to Intensive Care Unit (odds ratio [OR]: 15.486, 95% confidence interval [CI]: 3.175–75.541, P < 0.001); use of β-lactams and β-lactamase inhibitor combination (OR: 4.765, 95% CI: 1.508–15.055, P = 0.008); use of cephalosporins (OR: 8.033, 95% CI: 1.623–39.763, P = 0.011); fluoroquinolones (OR: 6.090, 95% CI: 1.343–27.613, P = 0.019); and indwelling of urethral catheter (OR: 6.164, 95% CI: 1.847–20.578, P = 0.003). However, older age (OR: 1.079, 95% CI: 1.005–1.158, P = 0.036), Charlson comorbidity index (OR: 4.690, 95% CI: 2.094–10.504, P = 0.000), and aminoglycoside use (OR: 670.252, 95% CI: 6.577–68,307.730, P = 0.006) were identified as independent risk factors for patient deaths with KP infection. The mortality of CRKP group was higher than that of the CSKP group. KPC gene did not play a role in the CRKP group. CRKP mortality was high.

Conclusion:

Implementation of infection control measures and protection of the immunefunction are crucial.

Polymicrobial Bacteremia Involving Klebsiella pneumoniae in Patients with Complicated Intra-Abdominal Infections: Frequency, Co-Pathogens, Risk Factors, and Clinical Outcomes

Background: Klebsiella pneumoniae has gained notoriety because of its high antibiotic resistance and mortality. We compared the clinical features and outcomes of polymicrobial bacteremia involving K. pneumoniae (PBKP). Patients and Methods: A retrospective observational study of patients with polymicrobial and monomicrobial bacteremia involving K. pneumoniae from January 2012 to December 2016 was performed. The expression of resistance and virulence genes of 27 strains was also compared by polymerase chain reaction (PCR). Results: Among the polymicrobial group, the most common accompanying micro-organism was Escherichia coli. No differences in the expression of resistance and virulence genes was found among the 27 strains collected from the group. The analysis of the outcomes revealed that the patients with PBKP were more likely to have recurrent blood stream infections (p = 0.038), longer intensive care unit (ICU) lengths of stay (p = 0.043), and a higher total hospitalization cost (p = 0.045). However, no substantial differences in mortality were found between the two groups. The multivariable analysis revealed that a longer hospital stay prior to the onset of bacteremia (>20 days) was an independent risk factor for PBKP (p = 0.034), and the Sequential Organ Failure Assessment (SOFA) score upon onset of infection (p = 0.013), the adequacy of source control (p < 0.001), and iron supplementation (p = 0.003) were identified as independent predictors of mortality in patients with KP bacteremia. Conclusions: The development of septic shock and the concomitant use of iron supplementation are associated with higher mortality in patients with KP bacteremia, and PBKP did not increase the mortality of these patients, possibly because of the ability of K. pneumoniae to obscure the effects of other bacteria. Thus, adequate source control is more important than high-dose antibiotic therapy and is linked to higher survival.

Epidemiology of carbapenem-resistant Klebsiella pneumoniae bloodstream infections after renal transplantation from donation after cardiac death in a Chinese hospital: a case series analysis

Background

Although the high mortality rates have been extensively reported worldwide, few studies have investigated the epidemiology of CRKP-BSIs in the early stage after kidney transplantation (KTx) from donation after cardiac death (DCD). We sought to describe the epidemiological and clinical characteristics of cases of carbapenem resistant Klebsiella pneumoniae bloodstream infections (CRKP-BSIs) in kidney transplantation recipients (KTRs) from DCD in our hospital.

Methods

A retrospective analysis of clinical data of CRKP-BSIs in KTRs admitted to a Chinese hospital in Beijing, China, between January 1, 2012 and December 31, 2016 was performed. The annual percentage of patients with CRKP, the annual number of total KTRs and KTRs from DCD were determined. The genetic relatedness of the strains was determined by polymerase chain reaction and pulse field gel electrophoresis (PFGE).

Results

During the study period, there were total 947 KTRs in our hospital, including 275 KTRs from DCD. Five incidences of CRKP-BSIs in KTRs were identified, and two of them (Case 1,3) from the same foreign hospital. The incidence of CRKP-BSIs in the early stage (within 3 months) following kidney transplantation (KTx) from DCD was about 1.1% (3/275). In Case 1–3 and 5, the rupture of renal transplant artery was presented on the 40th, 16th, 43th and 74th day after KTx, and in Case 4, the thrombus of renal transplant artery was presented on the 13th day after KTx. Three cases (Case 1,2,5) occurring pneumothorax on the 45th, 51th and 32th day after KTx. Four cases (Case 1–4) received the excision of the transplanted kidney for the treatment. Polymerase chain reaction showed the bands for case 2 were distinctive from other cases. Pulse field gel electrophoresis showed mainly three clusters of the bands for all the isolates.

Conclusions

During the study period, we observed an increase in the occurrence of CRKP-BSIs among KTRs from DCD in our hospital. We demonstrated that rupture/thrombus of the renal transplant artery was associated with CRKP-BSI in the early stage after KTx from DCD. Albeit the low incidence of CRKP-BSI (1.1%) after KTx from DCD, the high mortality (4/5) had been observed from the prognosis of the patients. Thorough surveillance of DCD donors, early identification of CRKP-BSI, necessary preventative measurements and use of appropriate treatments should be the strategy for CRKP-BSI in the early stage after KTx from DCD.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0355-8) contains supplementary material, which is available to authorized users.

Clinical and molecular characteristics, risk factors and outcomes of Carbapenem-resistant Klebsiella pneumoniae bloodstream infections in the intensive care unit

Background

To analyze the clinical characteristics and outcomes of carbapenem-resistant Klebsiella pneumoniae (CRKp) and carbapenem-susceptible K. pneumoniae (CSKp) bloodstream infections (BSIs), and to study the risk factors for development of CRKp BSI and K. pneumoniae BSI-related mortality.

Methods

A retrospective case control study of patients with K. pneumoniae BSI was conducted in the intensive care unit of the First Affiliated Hospital, Medical of College, Zhejiang University from January 2013 to December 2014. Carbapenem resistance was defined in accordance with the Clinical and Laboratory Standards Institute 2016 guidelines. Risk factors for the development of CRKp BSI and risk factors for mortality due to K. pneumoniae BSI were assessed. Virulence genes were detected by polymerase chain reaction assay.

Results

In total, 48 patients were enrolled in the study, including 31 (65%) patients with CRKp BSI and 17 (35%) patients with CSKp BSI. CSKp infection was associated with more severe clinical symptoms, particularly a higher serum creatinine level (165.06 ± 127.01 in the CSKp group vs. 93.77 ± 84.35 μmol/L in the CRKp group, p = 0.039), but there was no significant difference in prognosis between the CSKp and CRKp groups. On multivariate analysis, indwelling central venous catheter (p = 0.045) was the only factor independently associated with CRKp bacteremia. However, the mortality of K. pneumoniae BSI patients was not correlated with carbapenem resistance. In addition, the isolates had diverse clonality and different origins. The frequency of detection of the allS and magA virulence genes was higher in the CSKp group than in the CRKp group (alls p = 0.04; magA p = 0.047).

Conclusions

Patients in the CSKp group experienced more severe clinical symptoms, although mortality did not differ significantly between the CRKp and CSKp groups. An indwelling central venous catheter was the only factor independently associated with CRKp BSI. The mortality of patients with K. pneumoniae BSI was not associated with carbapenem resistance. The frequency of virulence genes was higher in the CSKp group than in the CRKp group.

Epidemiology of Klebsiella pneumoniae bloodstream infections in a teaching hospital: factors related to the carbapenem resistance and patient mortality

Background

Although Klebsiella pneumoniae bloodstream infections (KP-BSIs) have recently attracted attention due to an alarming raise in morbidity and mortality, there have been few reports on the epidemiology of KP-BSIs in mainland China. We sought to describe the epidemiological, microbiological, and clinical characteristics of KP-BSIs, focusing on the risk factors of carbapenem resistance and patient mortality.

Methods

A retrospective analysis of WHONET data of KP-BSI patients admitted to a teaching hospital in Shanghai, China, between January 1, 2011 and December 31, 2015 was performed, and the annual percentage of patients with carbapenem-resistant K. pneumoniae (CRKP) was determined. Risk factors related to the carbapenem resistance and patient mortality were analyzed using binary logistic regression model. The genetic relatedness of CRKP strains isolated from intensive care unit (ICU) patients was determined by pulsed-field gel electrophoresis (PFGE).

Results

A total of 293 incidences of KP-BSIs were identified in a 5-year period, 22.18% of these (65/293) were CRKP strains, and the proportion of CRKP-BSI in ICU was 59.62% (31/52), equaling the levels observed in the epidemic regions. A number of KP-BSIs (114), obtained from January 1, 2014, to December 31, 2015, were further investigated. Skin and soft tissue infection source (odds ratio [OR] 26.63, 95% confidence interval [CI] 4.8–146.8) and ICU-acquired infection (OR 5.82, 95% CI 2.0–17.2) was shown to be powerful risk factors leading to the development of CRKP-BSI. The crude 28-day mortality rates of KP-BSI and CRKP-BSI patients were 22.8% and 33.3%, respectively. Lung as the probable source of infection (OR 4.23, 95% CI 1.0–17.3), and high Sequential Organ Failure Assessment (SOFA) score (OR 1.40, 95% CI 1.2–1.6) were strong prognostic factors determining crude 28-day KP-BSI mortality rates. PFGE analysis demonstrated that 10/11 random CRKP isolates in ICU belonged to the same clonal type.

Conclusions

During the study period, we observed a significant increase in the occurrence of CRKP infections among the identified KP-BSIs in our hospital and especially in ICU, and we demonstrated that carbapenem resistance is associated with the increased mortality of KP-BSI patients.

Optimized Use of the MALDI BioTyper System and the FilmArray BCID Panel for Direct Identification of Microbial Pathogens from Positive Blood Cultures

Despite the current reliance on blood cultures (BCs), the diagnosis of bloodstream infections (BSIs) can be sped up using new technologies performed directly on positive BC bottles. Two methods (the MALDI BioTyper system and FilmArray blood culture identification [BCID] panel) are potentially applicable. In this study, we performed a large-scale clinical evaluation (1,585 microorganisms from 1,394 BSI episodes) on the combined use of the MALDI BioTyper and FilmArray BCID panel compared to a reference (culture-based) method. As a result, the causative organisms of 97.7% (1,362/1,394) of the BSIs were correctly identified by our MALDI BioTyper and FilmArray BCID-based algorithm. Specifically, 65 (5.3%) out of 1,223 monomicrobial BCs that provided incorrect or invalid identifications with the MALDI BioTyper were accurately detected by the FilmArray BCID panel; additionally, 153 (89.5%) out of 171 polymicrobial BCs achieved complete identification with the FilmArray BCID panel. Conversely, full use of the MALDI BioTyper would have resulted in the identification of only 1 causative organism in 97/171 (56.7%) of the polymicrobial cultures. By applying our diagnostic algorithm, the median time to identification was shortened (19.5 h versus 41.7 h with the reference method; P < 0.001), and the minimized use of the FilmArray BCID panel led to a significant cost savings. Twenty-six out of 31 microorganisms that could not be identified were species/genera not designed to be detected with the FilmArray BCID panel, indicating that subculture was not dispensable for a few of our BSI episodes. In summary, the fast and effective testing of BC bottles is realistically adoptable in the clinical microbiology laboratory workflow, although the usefulness of this testing for the management of BSIs remains to be established.