Blood stream infections

Predictors of thirty-day mortality among patients with blood stream infection with WHO priority pathogens: single centre exploratory study from a referral teaching hospital in central India

Background and Objectives

Bloodstream infection (BSI) is defined by the presence of viable microorganisms in the bloodstream. BSI is one of the major causes of sepsis and subsequent adverse clinical outcomes all across the globe. The present study was undertaken to identify clinico-epidemio-microbiological variables associated with 30-day mortality in patients having BSI with WHO priority pathogens.

Materials and Methods

The study was conducted at a public sector tertiary care institute in central India from April 2019 to March 2021. Blood samples collected from patients with clinical suspicion of sepsis, were processed by automated bacterial culture system and interpreted as per CLSI guidelines. Calculated sample size was 150. Data was analyzed by R software.

Results

Respiratory tract infection was the most common source (43.3%) of BSI, followed by the gastrointestinal (20%) and urinary tract (18.7%). Among the patients, 33% required invasive mechanical ventilation, and 31% required inotropes. Diabetes mellitus (DM) was the most common co-morbidity (34%). The incidence of multi-drug resistant organisms (MDRO) was 59.3%. Escherichia coli was the most commonly (24%) isolated organism, followed by Klebsiella pneumoniae (17.3%) and Acinetobacter baumannii (16%).

Conclusion

Higher age, higher qSOFA score / SIRS score / mean SOFA score at presentation had higher mortality. Use of mechanical ventilation and inotropes during treatment and isolation of critical category organisms of WPP and multi drug resistant organisms were independent 30-day mortality predictors.

Bacterial Translocation As the Origin of Gram-Negative Rods Bloodstream Infection Among Older Patients in Rural Hospitals: A Cross-Sectional Study

Introduction Bloodstream infections caused by Gram-negative rods are a pressing concern for the aging global population, particularly in rural settings. This study investigates the prevalence and entry pathways of Gram-negative rod bloodstream infections in elderly patients at a rural Japanese hospital, aiming to clarify the frequency and associated factors of straightforward entry and bacterial translocation. Method In this cross-sectional study, we analyzed electronic medical records of patients over 18 years of age with symptomatic Gram-negative rod bloodstream infections at Unnan City Hospital, Japan, from September 2021 to August 2023. We used multivariate logistic regression to assess factors of age, sex, body mass index, care dependency, and comorbidities. Results Among the participants who met the inclusion criteria, significant differences were observed in age, sex, inpatient status, and prevalence of conditions like respiratory diseases and cancer between the straightforward entry and bacterial translocation groups. Escherichia coli was the most common pathogen identified. Conclusion The study emphasizes the need for tailored medical approaches for elderly patients with bloodstream infections, considering their unique health profiles and risks. It highlights the importance of age, inpatient status, and cancer in determining infection risks, pointing to areas for further research to enhance infection management and healthcare outcomes in older populations.

Microbiological trends and mortality risk factors of central line-associated bloodstream infections in an academic medical center 2015-2020

BACKGROUND

Despite tremendous efforts to prevent central line-associated bloodstream infections, they still remain life-threatening complications among hospitalized patients with significant morbidity and mortality worldwide. The emerging antibiotic-resistant bacteria and other risk factors, including patient comorbidities, complicate patient management.

METHODS

A single-center retrospective observational study was conducted at King Fahad Hospital of the University, Eastern Province, Saudi Arabia. Hospitalized patients with confirmed central line-associated bloodstream infections between January 2015 and December 2020 were included. The primary objectives were to investigate the trends in antibiotic susceptibility patterns of the causative agents, coexisting comorbid conditions, and other risk factors associated with mortality.

RESULTS

A total of 214 patients with confirmed central line-associated bloodstream infections were included (CLABSI). The overall 30-day mortality rate was 33.6%. The infection rates per 1000 central line days for medical, surgical, and pediatric intensive care units were 4.97, 2.99, and 4.56 per 1000 CL days, respectively. The overall microbiological trends showed a predominance of Gram-negative agents, a steady increase of fungal CLABSI up to 24.0% in 2020, and a high prevalence of multidrug resistance up to 47% of bacterial CLABSI. In addition, the study indicates a significant negative surviving correlation with diabetes mellitus, cardiovascular disease, lung disease, chronic kidney disease, and the presence of ≥ 3 comorbidities (P < 0.05).

CONCLUSION

The microbiological trends of the study population demonstrated a steady increase of CLABSI caused by Candida spp. with a predominance of Gram-negative pathogens. Stratifying the patients according to relevant mortality risk factors, including patient comorbidities, will help reduce CLABSI rates and improve patient outcomes.

Performance of QMAC-dRASTTM (Direct Rapid Antimicrobial Susceptibility Testing) - a Newcomer in Phenotypic Automatic AST

Objective:

QMAC-dRASTTM is a phenotypic automatized Antibiotic Susceptibility Testing (AST) system based on microfluidic chip technology enabling observation of changes in a single bacterial cell under antibiotic treatment conditions. The 96 wells plate with dried antibiotics comprises 19 and 17 antibiotics for the Gram-Negatives (GNs) and Gram-Positives (GPs), respectively. Categorical (Sensitive, Intermediate or Resistant) results were compared to results obtained by our laboratory standard susceptibility testing procedure and given as Categorical Agreement (CA).

Methods:

In a 3-month period (2019/2020), blood cultures detected positive were included. Excluded were known off-panel strains of QMAC-dRASTTM, such as Gram-positive bacilli, Streptococcus and Candida species. Percentages of CA (CA, %) between QMAC-dRASTTM and routine testing methods used in the laboratory (EUCAST disc diffusion and/or etest/Broth Micro Dilution MIC), were calculated.

Results:

255 positive blood cultures from as many patients were examined. Of the positive blood culture strains, 144 were GNs, and 111 were GPs. An overall combined CA,% of 96.3 (2410 of 2502 determinations) was obtained, and discrepancies were noted in 92 of 2502 test results (3.7%). The percentage of very major errors (VMEs) was 0.7% for GNs and 2.2% for GPs. For 87% of blood culture specimens examined, susceptibility reports were available within 6-7 hours.

Conclusion:

The high CA,% for as well GNs as GPs are promising. The presented time to report data obtained by QMAC-dRASTTM in this study being of 3-8 hours for blood culture specimens examined strongly support a further possible improvement in the workflow for handling blood stream infections.

Investigation of Gram-Negative Bacilli Bacteraemia in a Tertiary Hospital in Nigeria: Epidemiology and Antimicrobial Susceptibility Pattern

Background: The re-emergence of gram-negative bacilli (GNB) as the predominant cause of bacteraemia remains a major concern, given the increasing trend of antimicrobial resistance among this group of organisms. Prompt and effective empirical antibiotic treatment is vital for preventing adverse outcomes; therefore, a good knowledge of the local bacteria profile is required. Objective: This study was designed to aid the establishment of local antibiogram and empirical treatment for GNB bacteremia in patients referred to the University of Port Harcourt Teaching Hospital (UPTH), Nigeria. Materials and Methods: A total of 230 blood samples were obtained from inpatients in different units/departments from December 2017 to November 2018. The blood cultures were processed using BACTEC 9060 automated blood culture system, and the isolates were identified using MICROBACT 12E identification kits (Oxoid, UK) at the microbiology laboratory of UPTH. Susceptibility and resistance tests were done according to CLSI guidelines. Relevant information was obtained from the laboratory request forms and patients’ clinical files. Results: The prevalence of GNB in the study was 28.9% (71/246). The distribution of GNB bacteraemia was as follows: surgical unit (26.8%), special care baby unit (SCBU) (23.9%), intensive care unit (ICU) (21.1%), and paediatric ward (8.5%). The most common source of bacteraemia was pneumonia (35.2%) followed by puerperal sepsis (15.1%) and urinary tract infection (UTI) (15.1%). Klebsiella pneumoniae was the most frequently isolated gram-negative bacillus (26.6%). The overall resistance rate of extended spectrum lactamase producing Enterobacteriaceae (ESBL) producers, carbapenemase producers, and multi-drug resistant (MDR) organisms was 32.4%, with Acinetobacter baumannii (50%) and Pseudomonas aeruginosa (27.3%) exhibiting the highest level of resistance to carbapenems. Conclusion: This study showed a high MDR rate among GNB causing bacteraemia in patients at UPTH. An urgent review of the current antimicrobial prescription policy and infection control measures is recommended.

Reversing the Trend of Antimicrobial Resistance in ICU: Role of Antimicrobial and Diagnostic Stewardship

Background

Increasing antimicrobial resistance (AMR) among common bacteria combined with the slow development of new antibiotics has posed a challenge to clinicians.

Aim and objective

To demonstrate whether antimicrobial and diagnostic stewardship program (ASP and DSP)-related interventions improve antibiotic susceptibilities among common bacteria causing bloodstream infections (BSI) in patients admitted to the intensive care unit (ICU) and whether these resulted in changes in the volume of antimicrobial consumption.

Materials and methods

We compared the susceptibility patterns of gram-negative bacteria (GNB) and gram-positive cocci (GPC) causing BSI and changes in the volume of antibiotics prescribed for the same before and after 2017 by a retrospective analysis.

Results

Postintervention, there was increased susceptibility of all GNBs to aminoglycosides; Escherichia coli and Klebsiella spp. to beta-lactambeta-lactamase inhibitors (BLBLI) combinations; and Klebsiella spp. and Pseudomonas spp. to carbapenems. Acinetobacter spp., Klebsiella spp., and Pseudomonas spp. showed improved susceptibility to doxycycline, whereas E. coli and Klebsiella spp. showed significantly improved susceptibility to fluoroquinolones. Among GPCs, there was increased susceptibility of Staphylococcus aureus (levofloxacin, clindamycin, and aminoglycoside), coagulase-negative S. aureus (CoNS) (chloramphenicol, levofloxacin, clindamycin, and aminoglycoside), and enterococci (chloramphenicol, levofloxacin, and clindamycin). There was a significant reduction in usage of antimicrobials for the treatment of GPCs (linezolid, doxycycline, chloramphenicol, levofloxacin, BLBLI, macrolide, and cephalosporin) and GNBs (levofloxacin, cephalosporin, carbapenem, and colistin), which caused BSI.

Conclusion

The present study illustrated that combined ASP and DSP interventions successfully reversed the resistance pattern of organisms causing BSI and resulted in a reduction in antibiotic utilization.

How to cite this article

Agarwal J, Singh V, Das A, Nath SS, Kumar R, Sen M. Reversing the Trend of Antimicrobial Resistance in ICU: Role of Antimicrobial and Diagnostic Stewardship. Indian J Crit Care Med 2021;25(6):635-641.

Albumin/Procalcitonin Ratio Is a Sensitive Early Marker of Nosocomial Blood Stream Infection in Patients with Intra-Cerebral Hemorrhage

Background: This study was performed to investigate the combination of admission serum procalcitonin (PCT) and albumin (alb) concentrations as a diagnostic predictor for discriminating patients with nosocomial blood stream infection (BSI) among those with spontaneous intra-cerebral hemorrhage (ICH). Methods: We conducted a retrospective study on patients with ICH and hospital-acquired BSI. Clinical and microbiological data were compared in patients who experienced nosocomial BSI during a hospital stay and those who did not. Multivariable logistic regression analyses were used to identify independent risk factors for nosocomial BSI. A receiver operating characteristic (ROC) curve analysis was performed to compare the predictive accuracy of the albumin:PCT ratio. Results: Patients with nosocomial BSI had lower albumin:PCT ratios than those without BSI (11.739 [3.192-38.452] versus 200.000 [40.634-417.500]; p < 0.001). Multivariable logistic regression analysis revealed that the albumin:PCT ratio (odds ratio [OR] 1.006; 95% confidence interval [CI] 1.002-1.011; p = 0.001], white blood cell count (OR 1.129; 95% CI 1.044-1.220; p = 0.002), and shock (OR 4.504; 95% CI 1.774-11.435; p = 0.002) were independent predictors of nosocomial BSI, allowing distinction of patients with the infection from those without. The area under the ROC curve for the albumin:PCT ratio was 0.830 (95% CI 0.768-0.892; p < 0.001). The cut-off value of the albumin:PCT ratio was <1.087 with a sensitivity of 90.6% and a specificity of 98.8%. In the subgroup of 85 patients with nosocomial BSI, the albumin:PCT ratio in patients with shock was lower than that in those without shock (7.154 [2.975-26.267] vs 28.000 [3.818-57.812]; p = 0.027). Conclusion: The albumin:PCT ratio can be used as an early diagnostic predictor for nosocomial BSI in patients with ICH. Additionally, BSI patients with lower albumin:PCT ratios are more likely to experience shock. The albumin:PCT ratio is expected to be a rapid and low-cost tool for clinical practice.

Bacterial Distribution and Risk Factors of Nosocomial Blood Stream Infection in Neurologic Patients in the Intensive Care Unit

OBJECTIVE

To investigate the risk factors and analyze the distribution of pathogens to provide a basis for the prevention of nosocomial blood stream infections (BSI) and reduce the incidence and mortality of nosocomial BSI in neurologic patients.

PATIENTS AND METHODS

A retrospective chart review of neurologic patients admitted to an adult intensive care unit from January 2012 to December 2017 was conducted. Every positive blood culture, clinical demographic, microbiologic and laboratory result, as well as 28-day outcome data, were compiled on a data collection sheet. The clinical significance of each isolate was determined; in addition, the antimicrobial susceptibilities of causative pathogens and the most likely source were recorded.

RESULTS

During the five-year study period, there were 121 nosocomial BSI yielding 151 isolates in 404 neurologic patients. Eighty-one percent of nosocomial BSI were monomicrobial. Gram-positive organisms caused 67.9% of these BSI, gram-negative organisms caused 32.1%, and fungi caused 0.8%. The crude incidence rate was approximately 29.9%, and the mortality of nosocomial BSI was as high as 29.8%. Intravascular lines were the most common source of nosocomial BSI (79.3%). The most common organisms causing BSI were coagulase-negative staphylococci (CoNS; 44.6% of isolates), Staphylococcus aureus (17.4%), Klebsiella species (11.5%), and Acinetobacter spp. (11.5%). Multivariable regression analysis revealed that the use of antibiotic agents in the 90 days prior (odds ratio [OR], 5.81; 95% confidence interval [CI], 3.18-10.62; p = 0.001), brain trauma (OR, 0.28; 95% CI, 0.15-0.51; p = 0.001), and transfusion (OR, 3.02; 95% CI, 1.45-6.29; p = 0.001) were significant predictors of nosocomial BSI.

CONCLUSIONS

The incidence and mortality of nosocomial BSI were high in our neurologic patients. Strictly aseptic operations, hand hygiene, and reasonable use of transfusions and antibiotic agents are effective measures to prevent nosocomial BSI.