First multicenter study on multidrug resistant bacteria carriage in Chinese ICUs

Optical interferometric: A novel approach for sensitive cost-effective measurement of multispecies biofilm from stress-tolerant field samples

Biofilms significantly impact public health and food safety within the meat industry. Detecting and quantifying biofilms are crucial tasks; however, their inherent complexity and heterogeneity, particularly in immature stages, present substantial challenges. Innovative techniques are necessary for accurate biofilm measurement, despite the presence of diverse interfering agents. An assessment of multispecies biofilms from cattle abattoir environmental samples (wall, basin, and door), equipment (tub, knives, and swivel), and offal (heart, lung, liver, spleen, rumen, and intestine). To elucidate the complexities of biofilm formation, a dual-pronged approach was employed, utilizing epifluorescence microscopy and optical interferometry to conduct a comprehensive analysis of biofilms that had developed on two distinct types of surfaces. Specifically, biotic surfaces that had undergone chilling and abiotic surfaces subjected to chlorination were examined to gain a deeper understanding of the structural and compositional characteristics of these microbial communities. Additionally, the presence of antibiotic-resistant bacteria within the submerged biofilm was evaluated. Despite chilling, the multispecies biofilm continued to grow from 0.2 μm to a maximum of 1.75 μm on the beef spleen surface, demonstrating the interplay of different bacterial species in biofilm formation on biotic surfaces. The highest antibacterial resistance was recorded for Staphylococcus simulans, followed by Staphylococcus saprophyticus and Staphylococcus aureus. In conclusion, the optical interferometer is a straightforward, fast, and sensitive technique for measuring biofilm thickness within the range of 0.1 to 4 μm. Progress in this field can revolutionize food safety, hygiene, biosecurity, and biomedical applications.

Development and Validation of a Nomogram Prediction Model for Multidrug-Resistant Organisms Infection in a Neurosurgical Intensive Care Unit

Objective

To develop a predictive model for assessing the risk of multidrug-resistant organisms (MDROs) infection and validate its effectiveness.

We conducted a study on a total of 2516 patients admitted to the neurosurgery intensive care unit (NICU) of a Grade-III hospital in Nantong City, Jiangsu Province, China, between January 2014 and February 2022. Patients meeting the inclusion criteria were selected using convenience sampling. The patients were randomly divided into modeling and validation groups in a 7:3 ratio. To address the category imbalance, we employed the Synthetic Minority Over-sampling Technique (SMOTE) to adjust the MDROs infection ratio from 203:1558 to 812:609 in the training set. Univariate analysis and logistic regression analysis were performed to identify risk factors associated with MDROs infection in the NICU. A risk prediction model was developed, and a nomogram was created. Receiver operating characteristic (ROC) analysis was used to assess the predictive performance of the model.

Patients and Methods

Results

Logistic regression analysis revealed that sex, hospitalization time, febrile time, invasive operations, postoperative prophylactic use of antibiotics, mechanical ventilator time, central venous catheter indwelling time, urethral catheter indwelling time, ALB, PLT, WBC, and L% were independent predictors of MDROs infection in the NICU. The area under the ROC curve for the training set and validation set were 0.880 (95% CI: 0.857-0.904) and 0.831 (95% CI: 0.786-0.876), respectively. The model's prediction curve closely matched the ideal curve, indicating excellent predictive performance.

Conclusion

The prediction model developed in this study demonstrates good accuracy in assessing the risk of MDROs infection. It serves as a valuable tool for neurosurgical intensive care practitioners, providing an objective means to effectively evaluate and target the risk of MDROs infection.

Risk predict model using multi-drug resistant organism infection from Neuro-ICU patients: a retrospective cohort study

The aim of this study was to analyze the current situation and risk factors of multi-drug-resistant organism (MDRO) infection in Neuro-intensive care unit (ICU) patients, and to develop the risk predict model. The data was collected from the patients discharged from Neuro-ICU of grade-A tertiary hospital at Guizhou province from January 2018 to April 2020. Binary Logistics regression was used to analyze the data. The model was examined by receiver operating characteristic curve (ROC). The grouped data was used to verify the sensitivity and specificity of the model. A total of 297 patients were included, 131 patients infected with MDRO. The infection rate was 44.11%. The results of binary Logistics regression showed that tracheal intubation, artery blood pressure monitoring, fever, antibiotics, pneumonia were independent risk factors for MDRO infection in Neuro-ICU (P < 0.05), AUC = 0.887. The sensitivity and specificity of ROC curve was 86.3% and 76.9%. The risk prediction model had a good predictive effect on the risk of MDRO infection in Neuro ICU, which can evaluate the risk and provide reference for preventive treatment and nursing intervention.

Deceased donors with multidrug-resistant organisms: implications and future directions

PURPOSE OF REVIEW

Organ utilization from donors infected or colonized with multidrug-resistant organisms (MDROs) remains inconsistent, and hesitancy to accept organs from these donors may relate to poor outcomes among solid organ transplant recipients with MDRO donor-derived infections (DDIs). An improved understanding of the risk factors for donor MDRO colonization or infection and the risk of MDRO DDI is needed to safely expand the donor pool while minimizing unnecessary organ discard.

RECENT FINDINGS

Recent studies have begun to delineate risk factors for MDRO acquisition among deceased donors and the epidemiology of MDRO DDIs, but additional efforts are warranted to inform optimal approaches to donor evaluation, risk stratification, management, interfacility and interagency data sharing, and approaches to recipient management.

SUMMARY

This review summaries recent data regarding risk factors for MDRO colonization and infection in deceased donors, epidemiology of MDRO DDIs, and current approaches to donors harboring MDROs and provides a framework for future research and collaboration.

Impact of donor multidrug-resistant organisms on solid organ transplant recipient outcomes

BACKGROUND

The impact of donor colonization or infection with multidrug-resistant organisms (MDROs) on solid organ transplant (SOT) recipient outcomes remains uncertain. We thus evaluated the association between donor MDROs and risk of posttransplant infection, graft failure, and mortality.

METHODS

A multicenter retrospective cohort study was performed. All SOT recipients with a local deceased donor were included. The cohort was divided into three exposure groups: recipients whose donors had (1) an MDRO, (2) a non-MDRO bacterial or candidal organism, or (3) no growth on cultures. The primary outcomes were (1) bacterial or invasive candidal infection within 3 months and (2) graft failure or death within 12 months posttransplant. Mixed effect multivariable frailty models were developed to evaluate each association.

RESULTS

Of 658 total SOT recipients, 93 (14%) had a donor with an MDRO, 477 (73%) had a donor with a non-MDRO organism, and 88 (13%) had a donor with no organisms on culture. On multivariable analyses, donor MDROs were associated with a significantly increased hazard of infection compared to those with negative donor cultures (adjust hazard ratio [aHR] 1.63, 95% CI 1.01-2.62, p = .04) but were not associated with graft failure or death (aHR 0.45, 95% CI 0.15-1.36, p = .16).

CONCLUSIONS

MDROs on donor culture increase the risk of early posttransplant infection but do not appear to affect long-term graft or recipient survival, suggesting organ donors with MDROs on culture may be safely utilized. Future studies aimed at reducing early posttransplant infections associated with donor MDROs are needed.

Clinical prediction tool for extended-spectrum beta-lactamase-producing enterobacterales as the etiology of a bloodstream infection in solid organ transplant recipients

BACKGROUND

Multidrug-resistant Gram-negative bacterial infections are increasingly common among solid organ transplant (SOT) recipients, leading to challenges in the selection of empiric antimicrobial therapy. We sought to develop a clinical tool to predict which SOT recipients are at high risk for extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (EB) bloodstream infection (BSI).

METHODS

A multicenter case-control study was performed. The source population included SOT recipients with an EB BSI between 2005 and 2018. Cases were those with ESBL-EB BSI; controls were those with non-ESBL EB BSI. The population was subdivided into derivation and validation cohorts based on study site. The predictive tool was developed in the derivation cohort through iterative multivariable logistic regression analyses that maximized the area under the receiver-operating curve (AUC). External validity was assessed using the validation cohort.

RESULTS

A total of 897 SOT recipients with an EB BSI were included, of which 539 were assigned to the derivation cohort (135, 25% ESBL-EB) and 358 to the validation cohort (221, 62% ESBL-EB). Using multivariable analyses, the most parsimonious model that was predictive of ESBL-EB BSI consisted of 10 variables, which fell into four clinical categories: prior colonization or infection with EB organisms, recent antimicrobial exposures, severity of preceding illness, and immunosuppressive regimen. This model achieved an AUC of 0.81 in the derivation cohort and 0.68 in the validation cohort.

CONCLUSIONS

Though further refinements are needed in additional populations, this tool shows promise for guiding empiric therapy for SOT recipients with EB BSI.

Prevalence and risk factors associated with multi-drug resistant organisms (MDRO) carriage among pediatric patients at the time of admission in a tertiary care hospital of a developing country. A cross-sectional study

Background

The rise of Multidrug-resistant organisms (MDROs) poses a considerable burden on the healthcare systems, particularly in low-middle income countries like Pakistan. There is a scarcity of data on the carriage of MDRO particularly in the pediatrics population therefore, we aimed to determine MDRO carriage in pediatric patients at the time of admission to a tertiary care hospital in Karachi, Pakistan, and to identify the risk factors associated with it.

Methods

A cross-sectional study conducted at the pediatric department of Aga Khan University Hospital (AKUH) from May to September 2019 on 347 children aged 1–18 years. For identification of MDRO (i.e., Extended Spectrum Beta-Lactamase (ESBL) producers, Carbapenem Resistant Enterobacteriaceae (CRE), Vancomycin Resistant Enterococci (VRE), Methicillin Resistant Staphylococcus aureus (MRSA), Multidrug-resistant (MDR) Acinetobacter species and MDR Pseudomonas aeruginosa), nasal swabs and rectal swabs or stool samples were cultured on specific media within 72 h of hospitalization. Data was collected on a predesigned structured questionnaire on demographics, prior use of antibiotics for > 48 h in the last 6 months, history of vaccination in last 6 months, exposure to health care facility regardless of the time of exposure, ICU stay for > 72 h, and about the prior use of medical devices (urinary catheter, central venous lines etc.) in last 1 year. Statistical analysis was performed by Standard statistical software.

Results

Out of 347 participants, 237 (68.3%) were found to be MDRO carriers. Forty nine nasal swabs from 346 children (14.2%) showed growth of MRSA. The majority of the stool/rectal swabs (n = 222 of 322; 69%) collected were positive for MDRO. The most isolated species were ESBL Escherichia coli 174/222 (78.3%) followed by ESBL Enterobacter species 37/222 (16.7%) and ESBL Klebsiella pneumoniae 35/222 (15.8%). On univariate analysis, none of the risk factors showed statistically significant association with MDRO carriage.

Conclusion

Overall, a high prevalence of MDRO carriage was identified among admitted pediatric patients. Implementation of systematic screening may help to identify true burden of MDROs carriage in the health care settings.

When Multidrug-Resistant Organism (MDRO)-Positive ICU Patient Isolation and Cohorting Is Not Feasible, What Comes Next?

Background The need for the implementation of an infection prevention strategy that included patient isolation and a cohorting procedure emerged in our ICU. Yet, isolation, as well as cohorting, were not feasible due to certain barriers associated with a high colonization pressure, open-plan ICU, inadequate bed separation, a limited number of isolation rooms, and nursing shortage. Despite these limitations, we tried to upgrade our ICU's infection prevention efforts by developing the "universal use of contact precautions approach" for infection prevention and control for all the patients with and without multidrug-resistant organisms (MDROs), cohorting, and single room isolation. The study aimed to evaluate the effectiveness of our approach. Methods A prospective cohort study using surveillance screening cultures for Methicillin-resistant Staphylococcus aureus (MRSA) and MDROs for a period of 18 weeks from October 1, 2018, to January 31, 2019. The main purpose of the approach was to isolate all patients (regardless of their MDRO/MRSA status) in their own bed space as if they were in an isolation room for the entire duration of their ICU hospitalization, in such a way as to prevent horizontal transmission of infection (infection acquisition) in our open-plan ICU.  Results Seventy-eight patients were admitted to our ICU for a total of 942 patient-days; a total of 432 swabs were collected during the study period. A total of 17 (21.8%) patients were admitted with a pre-existing infection while two (2.5%) patients acquired an infection during their ICU stay (one with Acinetobacter baumannii andone with Pseudomonas aeruginosa; 1.28 acquisition per 1000 patient-days). No transmission was documented for Klebsiella pneumoniae, Enterococcus faecalis, and Staphylococcus aureus. Conclusions Our MDRO acquisition rates suggested that the implementation of our infection control strategy potentially prevents the horizontal transmission of pathogens in an open-plan ICU, despite the high colonization pressure and the lack of isolation and cohorting procedures.

Early Screening of Risk for Multidrug-Resistant Organisms in the Emergency Department in Patients With Pneumonia and Early Septic Shock: Single-Center, Retrospective Cohort Study

OBJECTIVES

Pneumonia is the fourth leading cause of death globally, with rapid progression during sepsis. Multidrug-resistant organisms (MDROs) are becoming more common with some healthcare-associated pneumonia events. Early detection of MDRO risk improves the outcomes; however, MDROs risk in pneumonia with sepsis is unknown. This study investigated the disease outcomes of pneumonia with septic shock in patients admitted in the emergency department (ED) intensive care unit (ICU), a population with a high prevalence of MDROs, after early screening of MDROs risk.

METHODS

In this retrospective cohort study, patients with pneumonia and early septic shock (n = 533) admitted to the ED at the Taipei Tzu Chi Hospital from 2013 to 2019 were selected. The study population was divided into four subgroups after the MDROs risk and screening procedure were completed within 1 or 6 h of admission. ICU mortality and multidrug antibiotic therapy were compared.

RESULTS

The high-risk MDROs groups had higher percentage of P aeruginosa than the low-risk group. Furthermore, the appropriate ED first antibiotics were higher in the 1-h subgroup than in the 6-h subgroup of the high-risk MDROs group. In multivariate analysis, the 6-h high-risk MDROs group had an adjusted odds ratio of 7.191 (95% CI: 2.911-17.767, P < 0.001) and 2.917 (95% CI: 1.456-5.847, P = 0.003) for ICU mortality and multidrug therapy in the ICU, respectively, after adjusting for other confounding factors.

CONCLUSIONS

MDRO screening within 1 h is recommended following admission of patients with pneumonia and early septic shock in the ED, especially in areas with a high prevalence of MDROs.

Acquisition of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae in intensive care units in Thailand

This study aimed to assess the prevalence and associated risk factors for extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EK) acquisition among patients staying in medical and surgical Intensive Care Units (ICU) in Northern Thailand. Rectal swabs were collected from 206 ICU patients upon admission and discharge. Overall, the ESBL-EK acquisition rate among patients during ICU stay was 29.6%. Acquisition rate was significantly higher for K. pneumoniae (20.9%) than that of E. coli (12.1%) (p = 0.024). Multivariate logistic regression analysis identified the use of third generation cephalosporin (p = 0.008) as a risk factor for ESBL-EK acquisition. Sixty-eight ESBL-EK isolates (25 E. coli and 43 K. pneumoniae) were recovered. The majority of ESBL-EK isolates (≥88%) were resistant to ceftazidime, cefepime and aztreonam. Fifty-two acquired ESBL-EK isolates (76.5%) were positive for bla_CTX-M and 4 K. pneumoniae isolates simultaneously carried bla_NDM-1. Our results reveal that ICU patients could acquire ESBL-EK during hospitalization and the use of third generation cephalosporin should be strictly controlled to prevent the acquisition of ESBL-EK among ICU patients.

What we can do? The risk factors for multi-drug resistant infection in pediatric intensive care unit (PICU): a case-control study

Background

The risk factors for multi-drug resistant infection (MDRI) in the pediatric intensive care unit (PICU) remain unclear. It’s necessary to evaluate the epidemiological characteristics and risk factors for MDRI in PICU, to provide insights into the prophylaxis of MDRI clinically.

Methods

Clinical data of 79 PICU children with MDRI were identified, and 80 children in PICU without MDRI in the same period were selected as control group. The related children’s characteristics, clinical care, microbiologic data, treatments provided, and outcomes of the patients with were reviewed and collected. Univariate and multivariate logistic regression analyses were performed to identify the potential risks of MDRI in PICU.

Results

Of the diagnosed 79 cases of MDRI, there were28 cases of CR-AB, 24 cases of MRSA, 22 cases of PDR-PA,3 cases of VRE and 2 cases of CRE respectively. Univariate analyses indicated that the length of PICU stay, the duration of mechanical ventilation > 5 days, parenteral nutrition, coma, urinary catheter indwelling, invasive operation, 2 or more antibiotics use were associated with MDRIs (all p < 0.05); The logistic multiple regression analyses indicated that coma, parenteral nutrition, 2 or more antibiotics use and the duration of mechanical ventilation > 5 days were independent risk factors associated with MDRI (all p < 0.05).

Conclusions

This present study has identified several potentially modifiable risk factors for MDRI in PICU, it’s conducive to take appropriate measures targeting risk factors of MDRI for health care providers to reduce MDRI.

Gastrointestinal colonization with multidrug-resistant Gram-negative bacteria during extracorporeal membrane oxygenation: effect on the risk of subsequent infections and impact on patient outcome

Background

In ICU patients, digestive tract colonization by multidrug-resistant (MDR) Gram-negative (G−) bacteria is a significant risk factor for the development of infections. In patients undergoing extracorporeal membrane oxygenation (ECMO), colonization by MDR bacteria and risk of subsequent nosocomial infections (NIs) have not been studied yet. The aim of this study is to evaluate the incidence, etiology, risk factors, impact on outcome of gastrointestinal colonization by MDR G− bacteria, and risk of subsequent infections in patients undergoing ECMO.

Methods

This is a retrospective analysis of prospectively collected data: 105 consecutive patients, treated with ECMO, were admitted to the ICU of an Italian tertiary referral center (San Gerardo Hospital, Monza, Italy) from January 2010 to November 2015. Rectal swabs for MDR G− bacteria were cultured at admission and twice a week. Only colonization and NIs by MDR G− bacteria were analyzed.

Results

Ninety-one included patients [48.5 (37–56) years old, 63% male, simplified acute physiology score II 37 (32–47)] underwent peripheral ECMO (87% veno-venous) for medical indications (79% ARDS). Nineteen (21%) patients were colonized by MDR G− bacteria. Male gender (OR 4.03, p = 0.029) and duration of mechanical ventilation (MV) before ECMO > 3 days (OR 3.57, p = 0.014) were associated with increased risk of colonization. Colonized patients had increased odds of infections by the colonizing germs (84% vs. 29%, p < 0.001, OR 12.9), longer ICU length of stay (LOS) (43 vs. 24 days, p = 0.002), MV (50 vs. 22 days, p < 0.001) and ECMO (28 vs. 12 days, p < 0.001), but did not have higher risk of death (survival rate 58% vs. 67%, p = 0.480, OR 0.68). Infected patients had almost halved ICU survival (46% vs. 78%, p < 0.001, OR 4.11).

Conclusions

In patients undergoing ECMO for respiratory and/or circulatory failure, colonization by MDR G− bacteria is frequent and associated with more the tenfold odds for subsequent infection. Those infections are associated with an increased risk of death.

Acquisition of antimicrobial-resistant bacteria in the absence of antimicrobial exposure: A systematic review and meta-analysis

Objective:

The main risk factor for acquisition of antimicrobial-resistant bacteria (ARB) is antimicrobial exposure, although acquisition can occur in their absence. The aim of this study was to quantify the proportion of patients who acquire ARB without antimicrobial exposure.

Study design:

We searched Medline, Embase, and the Cochrane library for publications between January 1, 2000, and July 24, 2017, to identify studies of ARB acquisition in endemic settings. Studies required collection of serial surveillance cultures with acquisition defined as a negative baseline culture and a subsequent positive culture for an ARB, including either multidrug-resistant gram-negative bacteria or antimicrobial-resistant enterococci. Intervention studies were excluded. For each study, the proportion of patients who acquired an ARB but were not exposed to antimicrobials during the study period was quantified.

Results:

A total of 4,233 citations were identified; 147 underwent full-text review. Of these, 10 studies met inclusion criteria; 7 studies were considered to be at low risk of bias; and 6 studies were conducted in the intensive care unit (ICU) setting. The overall summary estimate for the proportion of patients who were not exposed to antimicrobials among those who acquired an ARB was 16.6% (95% CI, 7.8%–31.8%; P < .001), ranging from 0% to 57.1%. We observed no heterogeneity in the ICU studies but high heterogeneity among the non-ICU studies.

Conclusion:

In most included studies, a subset of patients acquired an ARB but were not exposed to antimicrobials. Future studies need to address transmission dynamics of ARB acquisition in the absence of antimicrobials.

Hospital-acquired colonization and infections in a Vietnamese intensive care unit

Data concerning intensive care unit (ICU)-acquired bacterial colonization and infections are scarce from low and middle-income countries (LMICs). ICU patients in these settings are at high risk of becoming colonized and infected with antimicrobial-resistant organisms (AROs). We conducted a prospective observational study at the Ho Chi Minh City Hospital for Tropical Diseases, Vietnam from November 2014 to January 2016 to assess the ICU-acquired colonization and infections, focusing on the five major pathogens in our setting: Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Klebsiella spp., Pseudomonas spp. and Acinetobacter spp., among adult patients with more than 48 hours of ICU stay. We found that 61.3% (223/364) of ICU patients became colonized with AROs: 44.2% (161/364) with rectal ESBL-producing E. coli and Klebsiella spp.; 30.8% (40/130) with endotracheal carbapenemase-producing Acinetobacter spp.; and 14.3% (52/364) with nasal methicillin-resistant S. aureus. The incidence rate of ICU patients becoming colonized with AROs was 9.8 (223/2,276) per 100 patient days. Significant risk factor for AROs colonization was the Charlson Comorbidity Index score. The proportion of ICU patients with HAIs was 23.4% (85/364), and the incidence rate of ICU patients contracting HAIs was 2.3 (85/3,701) per 100 patient days. The vascular catheterization (central venous, arterial and hemofiltration catheter) was significantly associated with hospital-acquired bloodstream infection. Of the 77 patients who developed ICU-acquired infections with one of the five specified bacteria, 44 (57.1%) had prior colonization with the same organism. Vietnamese ICU patients have a high colonization rate with AROs and a high risk of subsequent infections. Future research should focus on monitoring colonization and the development of preventive measures that may halt spread of AROs in ICU settings.

[Clinical significance and risk factors for multidrug resistant Enterobacteriaceae colonization]

OBJECTIVE

To identify the main risk factors of rectal colonization by multidrug resistant Enterobacteriaceae (MRE), and their clinical impact.

METHODS

An observational, prospective cohort study was carried out, between April 2016 and June 2017, where every Monday of each week rectal samples were taken from all the patients admitted at that moment in the Intensive Care Unit. We performed a descriptive analysis of all the variables collected during the study and a multivariate logistic regression analysis to determine the independent association of carriers of MRE against non-carriers and several possible risk factors.

RESULTS

During the study period, rectal samples were collected from 208 patients. Of the 208, 30 were carriers of MRE, with a mean age of 64.3 years and a mean score of APACHE II (Acute Physiology and Chronic Health Evaluation II) of 20.6 points. 70% of the patients with MRE had a positive result in the first rectal sample. The variables that were associated with an increased risk of rectal colonization by EMR in the regression analysis were the administration of antibiotics in the previous month (OR 5.2, 95% CI 1.71-15.79) and post-surgical patients (OR 3.8; IC95% 1.51 - 9.51). Although patients with EMR had more frequent infections by these bacteria, no differences were observed in mortality between the two groups.

CONCLUSIONS

Post-surgical patients admitted to the ICU and those who received antibiotic treatment in the previous month have a higher probability of colonization due to MRE. The colonized patients presented more frequent infections by MRE although it was not associated to a higher mortality.

Incidence of Multidrug-Resistant Organism Among Children Admitted to Pediatric Intensive Care Unit in a Developing Country

AIM

Multidrug-resistant infections are an increasingly common condition particularly in critical care units. This study aimed to determine the incidence and types of resistant bacteria acquired in a pediatric intensive care unit (PICU) of a university hospital.

SUBJECT AND METHODS

A prospective study was conducted during the year 2016. All children aged below 16 years were studied for infection development and pattern of susceptibility to various groups of antibiotics.

RESULTS

A total of 264 patients were admitted to the PICU: 16 patients had community-acquired infection (CAI), 23 had hospital-acquired infection, and 24 patients had PICU-acquired infection (with 36 episodes) which is equivalent to 14.75 case/1,000 patient days. The study revealed high incidence of resistant organisms in the PICU but more important is the appearance of multi- and extreme drug-resistant bacteria in CAI. The study revealed that gram-negative bacteria were more prevalent in PICU, especially Klebsiella (30.5%), Acinetobacter baumanii (22.22%), and Pseudomonas (16.67%). Infection with resistant organisms in the PICU caused initial treatment failure and increased fourfold risk of mortality.

CONCLUSION

The incidence of resistant bacteria especially gram-negative pathogens was very high in the PICU. The top three resistant organisms of concern were Klebsiella, Acinetobacter, and Pseudomonas. This is a global concern that necessitates new strategies.

Identification of a novel linear B-cell epitope as a vaccine candidate in the N2N3 subdomain of Staphylococcus aureus fibronectin-binding protein A

PURPOSE

To explore an epitope-based vaccine against Staphylococcus aureus, we screened the epitopes in the N2N3 subdomain of fibronectin-binding protein A (FnBPA) as a surface component of S. aureus.

METHODOLOGY

We expressed N2N3 proteins and prepared monoclonal antibodies (mAbs) against N2N3 by the hybridoma technique, before screening the B-cell epitopes in N2N3 using a phage-displayed random 12-mer peptide library with these mAbs against N2N3. Finally, we analysed the characters of the screened epitopes using immunofluorescence and an S. aureus infection assay.

RESULTS

In this paper, we identified a linear B-cell epitope in N2N3 through screening a phage-displayed peptide library with a 3C3 mAb against the N2N3. The 3C3 mAb recognized the 159IETFNKANNRFSH171 sequence of the N2N3 subdomain. Subsequently, site-directed mutagenic analysis demonstrated that residues F162, K164, N167, R168 and F169 formed the core of 159IETFNKANNRFSH171, and this core motif was the minimal determinant of the B-cell epitope recognized by the 3C3 mAb. The epitope 159IETFNKANNRFSH171 showed high homology among different S. aureus strains. Moreover, this epitope was exposed on the surface of the S. aureus by using an enzyme-linked immunosorbent assay (ELISA) assay and an indirect immunofluorescence assay. As expected, the epitope peptide evoked a protective immune response against S. aureus infection in immunized mice.

CONCLUSION

We identified a novel linear B-cell epitope, 159IETFNKANNRFSH171, in the N2N3 subdomain of S. aureus fibronectin-binding protein A that is recognized by 3C3 mAb, which will contribute to the further study of an epitope-based vaccine candidate against S. aureus.

Effectiveness of Chinese Herbal Medicine Combined with Antibiotics for Extensively Drug-Resistant Enterobacteria and Nonfermentative Bacteria Infection: Real-Life Experience in a Retrospective Cohort

Chinese herbal medicines (CHMs) have been successfully used in the treatment of infectious diseases, yet the effectiveness of CHMs for extensively drug-resistant enterobacteria (XDRE) infection remains unclear. Herein we developed a retrospective multicenter study including 766 patients with XDRE and nonfermentative bacteria (NFB) infection to investigate the effectiveness of CHMs combined with antibiotics in the treatment of XDRE infections in clinical daily practice in a cohort of patients and compared the regular antibiotics monotherapy. After 14-day treatment, the 547 patients accepted CHMs combined with antibiotics therapy indicating a more desirable effectiveness compared to the 219 patients treated with antibiotics monotherapy. The primary evaluation indexes included white blood cell count (WBC) and percentage of neutrophil (N%) in blood test. Secondary evaluation indexes consisted of body temperature, breath, heart rate, platelets, hemoglobin, red blood cell, albumin, creatinine, glucose, and 28-day survival rates. Briefly speaking, in our experience, CHMs combined with antibiotics therapy achieved more desirable effectiveness in treating XDRE infections compared with antibiotics monotherapy, and CHMs might be a potential huge resource in the field of XDRE infection management and enlighten the new antibiotics research and development. This trial is registered with ChiCTR-ORC-17011760.

ICU Acquisition Rate, Risk Factors, and Clinical Significance of Digestive Tract Colonization With Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the acquisition rate, identify risk factors, and estimate the risk for subsequent infection, associated with the colonization of the digestive tract with extended-spectrum beta-lactamase-producing Enterobacteriaceae during ICU-hospitalization.

DATA SOURCES

PubMed, EMBASE, and reference lists of all eligible articles.

STUDY SELECTION

Included studies provided data on ICU-acquired colonization with extended-spectrum beta-lactamase-producing Enterobacteriaceae in previously noncolonized and noninfected patients and used the double disk synergy test for extended-spectrum beta-lactamase-producing Enterobacteriaceae phenotypic confirmation. Studies reporting extended-spectrum beta-lactamase-producing Enterobacteriaceae outbreaks or data on pediatric population were excluded.

DATA EXTRACTION

Two authors independently assessed study eligibility and performed data extraction.

DATA SYNTHESIS

Thirteen studies (with 15,045 ICUs-patients) were evaluated using a random-effect model and a meta-regression analysis. The acquisition rate of digestive tract colonization during ICU stay was 7% (95% CI, 5-10) and it varies from 3% (95% CI, 2-4) and 4% (95% CI, 2-6) in the Americas and Europe to 21% (95% CI, 9-35) in the Western Pacific region. Previous hospitalization (risk ratio, 1.57 [95% CI, 1.07-2.31]) or antibiotic use (risk ratio, 1.65 [95% CI, 1.15-2.37]) and exposure to beta-lactams/beta-lactamase inhibitors (risk ratio, 1.78 [95% CI, 1.24-2.56]) and carbapenems (risk ratio, 2.13 [95% CI, 1.49-3.06]) during the ICU stay were independent risk factors for ICU-acquired colonization. Importantly, colonized patients were more likely to develop an extended-spectrum beta-lactamase-producing Enterobacteriaceae infection (risk ratio, 49.62 [95% CI, 20.42-120.58]). The sensitivity and specificity of prior colonization to predict subsequent extended-spectrum beta-lactamase-producing Enterobacteriaceae infection were 95.1% (95% CI, 54.7-99.7) and 89.2% (95% CI, 77.2-95.3), respectively.

CONCLUSIONS

The ICU acquisition rate of extended-spectrum beta-lactamase-producing Enterobacteriaceae ranged from 5% to 10%. Previous use of beta-lactam/beta-lactamase or carbapenems and recent hospitalization were independent risk factors for extended-spectrum beta-lactamase-producing Enterobacteriaceae colonization, and colonization was associated with significantly higher frequency of extended-spectrum beta-lactamase-producing Enterobacteriaceae subsequent infection and increased mortality.

Carriage of antibiotic-resistant Enterobacteriaceae in hospitalised children in tertiary hospitals in Harare, Zimbabwe

Background

Extended-spectrum β-lactamase-producing and gentamicin resistant Enterobacteriaceae are increasingly recognised as a major cause of infection in low-income countries. We assessed the prevalence of gastrointestinal carriage of these bacteria in hospitalised children in Harare, Zimbabwe.

Methods

We conducted a cohort study in paediatric inpatients at two tertiary-referral hospitals between May and July 2015. Rectal swabs and faecal samples were collected within 24 h of admission and further follow-up samples were collected on alternate days during hospitalization. Disc-based, selective and enrichment methods were used to detect carriage of these two forms of resistance. Standard methods were used to confirm resistance status and determine the susceptibility of resistant isolates to other commonly-used antibiotics.

Results

One hundred and sixty four paediatric inpatient admissions (median age = 1.0 year, IQR = 0.2–2.2years) were enrolled, and an average of 1.9 faecal samples per patient were collected. On admission, 68/164 (41%) patients had both ESBL and gentamicin-resistant Enterobacteriaceae detected, 18 (11%) had ESBL only, 17 (10%) had gentamicin resistance only and 61 (37%) had negative screening for both forms of resistance. During hospitalisation, 32/164 (20%) patients were found to have a type of resistant organism which was not present in their admission sample. We found that faecal samples and use of a selective enrichment broth enhanced the detection of resistant organisms. Amongst resistant bacteria isolated, there were high levels of resistance to ciprofloxacin and chloramphenicol, but not ertapenem.

Conclusions

More than half of children had enteric carriage of a clinically-relevant form of antibiotic resistance on admission to public-sector hospitals in urban Zimbabwe. Additionally, a fifth of children acquired a further form of resistance during hospitalisation. Urgent action is needed to tackle the spread of antibiotic resistant enteric bacteria in African hospitals.

High Prevalence of Gut Microbiota Colonization with Broad-Spectrum Cephalosporin Resistant Enterobacteriaceae in a Tunisian Intensive Care Unit

Healthcare-associated infections due to cefotaxime-resistant (CTX-R) Enterobacteriaceae have become a major public health threat, especially in intensive care units (ICUs). Often acquired nosocomially, CTX-R Enterobacteriaceae can be introduced initially by patients at admission. This study aimed to determine the prevalence and genetic characteristics of CTX-R Enterobacteriaceae-intestinal carriage in ICU patients, to evaluate the rate of acquisition of these organisms during hospitalization, and to explore some of the associated risk factors for both carriage and acquisition. Between December 2014 and February 2015, the 63 patients admitted in the ICU of Charles Nicolle hospital were screened for rectal CTX-R Enterobacteriaceae colonization at admission and once weekly thereafter to identify acquisition. CTX-R Enterobacteriaceae fecal carriage rate was 20.63% (13/63) at admission. Among the 50 non-carriers, 35 were resampled during their hospitalization and the acquisition rate was 42.85% (15/35). Overall, 35 CTX-R Enterobacteriaceae isolates were collected from 28 patients (25 Klebsiella pneumoniae, seven Escherichia coli, and three Enterobacter cloacae strains). Seven patients were simultaneously colonized with two CTX-R Enterobacteriaceae isolates. CTX-M-15 was detected in most of the CTX-R Enterobacteriaceae isolates (30/35, 88.23%). Three strains co-produced CMY-4 and 22 strains were carbapenem-resistant and co-produced a carbapenemase [OXA-48 (n = 13) or NDM-1 (n = 6)]. Molecular typing of K. pneumoniae strains, revealed eight Pulsed field gel electrophoresis (PFGE) patterns and four sequence types (ST) [ST101, ST147, ST429, and ST336]. However, E. coli isolates were genetically unrelated and belonged to A (n = 2), B1 (n = 2) and B2 (n = 3) phylogenetic groups and to ST131 (two strains), ST572 (two strains), ST615 (one strain) and ST617 (one strain). Five colonized patients were infected by CTX-R Enterobacteriaceae (four with the same strain identified from their rectal swab and one with a different strain). Whether imported or acquired during the stay in the ICU, colonization by CTX-R Enterobacteriaceae is a major risk factor for the occurrence of serious nosocomial infections. Their systematic screening in fecal carriage is mandatory to prevent the spread of these multidrug resistant bacteria.