Risk for subsequent infection and mortality after hospitalization among patients with multidrug-resistant gram-negative bacteria colonization or infection

Risk factors for colonization with extended-spectrum cephalosporin-resistant and carbapenem-resistant Enterobacterales among hospitalized patients in Guatemala: An Antibiotic Resistance in Communities and Hospitals (ARCH) study

Objectives

The spread of extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) and carbapenem-resistant Enterobacterales (CRE) has resulted in increased morbidity, mortality, and health care costs worldwide. To identify the factors associated with ESCrE and CRE colonization within hospitals, we enrolled hospitalized patients at a regional hospital located in Guatemala.

Methods

Stool samples were collected from randomly selected patients using a cross-sectional study design (March-September, 2021), and samples were tested for the presence of ESCrE and CRE. Hospital-based and household variables were examined for associations with ESCrE and CRE colonization using lasso regression models, clustered by ward (n = 21).

Results

A total of 641 patients were enrolled, of whom complete data sets were available for 593. Colonization with ESCrE (72.3%, n = 429/593) was negatively associated with carbapenem administration (odds ratio [OR] 0.21, 95% confidence interval [CI] 0.11-0.42) and positively associated with ceftriaxone administration (OR 1.61, 95% CI 1.02-2.53), as was reported hospital admission within 30 days of the current hospitalization (OR 2.84, 95% CI 1.19-6.80). Colonization with CRE (34.6%, n = 205 of 593) was associated with carbapenem administration (OR 2.62, 95% CI 1.39-4.97), reported previous hospital admission within 30 days of current hospitalization (OR 2.58, 95% CI 1.17-5.72), hospitalization in wards with more patients (OR 1.05, 95% CI 1.02-1.08), hospitalization for ≥4 days (OR 3.07, 95% CI 1.72-5.46), and intubation (OR 2.51, 95% CI 1.13-5.59). No household-based variables were associated with ESCrE or CRE colonization in hospitalized patients.

Conclusion

The hospital-based risk factors identified in this study are similar to what has been reported for risk of health care-associated infections, consistent with colonization being driven by hospital settings rather than community factors. This also suggests that colonization with ESCrE and CRE could be a useful metric to evaluate the efficacy of infection and prevention control programs in clinics and hospitals.

The Importance of Carbapenemase-Producing Enterobacterales in African Countries: Evolution and Current Burden

Antimicrobial resistance (AMR) is a worldwide healthcare problem. Multidrug-resistant organisms (MDROs) can spread quickly owing to their resistance mechanisms. Although colonized individuals are crucial for MDRO dissemination, colonizing microbes can lead to symptomatic infections in carriers. Carbapenemase-producing Enterobacterales (CPE) are among the most important MDROs involved in colonizations and infections with severe outcomes. This review aimed to track down the first reports of CPE in Africa, describe their dissemination throughout African countries and summarize the current status of CRE and CPE data, highlighting current knowledge and limitations of reported data. Two database queries were undertaken using Medical Subject Headings (MeSH), employing relevant keywords to identify articles that had as their topics beta-lactamases, carbapenemases and carbapenem resistance pertaining to Africa or African regions and countries. The first information on CPE could be traced back to the mid-2000s, but data for many African countries were established after 2015-2018. Information is presented chronologically for each country. Although no clear conclusions could be drawn for some countries, it was observed that CPE infections and colonizations are present in most African countries and that carbapenem-resistance levels are rising. The most common CPE involved are Klebsiella pneumoniae and Escherichia coli, and the most prevalent carbapenemases are NDM-type and OXA-48-type enzymes. Prophylactic measures, such as screening, are required to combat this phenomenon.

Characterisation of colistin resistance in Gram-negative microbiota of pregnant women and neonates in Nigeria

A mobile colistin resistance gene mcr was first reported in 2016 in China and has since been found with increasing prevalence across South-East Asia. Here we survey the presence of mcr genes in 4907 rectal swabs from mothers and neonates from three hospital sites across Nigeria; a country with limited availability or history of colistin use clinically. Forty mother and seven neonatal swabs carried mcr genes in a range of bacterial species: 46 Enterobacter spp. and single isolates of; Shigella, E. coli and Klebsiella quasipneumoniae. Ninety percent of the genes were mcr-10 (n = 45) we also found mcr-1 (n = 3) and mcr-9 (n = 1). While the prevalence during this collection (2015-2016) was low, the widespread diversity of mcr-gene type and range of bacterial species in this sentinel population sampling is concerning. It suggests that agricultural colistin use was likely encouraging sustainment of mcr-positive isolates in the community and implementation of medical colistin use will rapidly select and expand resistant isolates.

Epidemiology and outcomes of multidrug-resistant bacterial infection in non-cystic fibrosis bronchiectasis

PURPOSE

Multidrug-resistant (MDR) bacteria impose a considerable health-care burden and are associated with bronchiectasis exacerbation. This study investigated the clinical outcomes of adult patients with bronchiectasis following MDR bacterial infection.

METHODS

From the Chang Gung Research Database, we identified patients with bronchiectasis and MDR bacterial infection from 2008 to 2017. The control group comprised patients with bronchiectasis who did not have MDR bacterial infection and were propensity-score matched at a 1:2 ratio. The main outcomes were in-hospital and 3-year mortality.

RESULTS

In total, 554 patients with both bronchiectasis and MDR bacterial infection were identified. The types of MDR bacteria that most commonly affected the patients were MDR- Acinetobacter baumannii (38.6%) and methicillin-resistant Staphylococcus aureus (18.4%), Extended-spectrum-beta-lactamases (ESBL)- Klebsiella pneumoniae (17.8%), MDR-Pseudomonas (14.8%), and ESBL-E. coli (7.5%). Compared with the control group, the MDR group exhibited lower body mass index scores, higher rate of chronic bacterial colonization, a higher rate of previous exacerbations, and an increased use of antibiotics. Furthermore, the MDR group exhibited a higher rate of respiratory failure during hospitalization (MDR vs. control, 41.3% vs. 12.4%; p < 0.001). The MDR and control groups exhibited in-hospital mortality rates of 26.7% and 7.6%, respectively (p < 0.001); 3-year respiratory failure rates of 33.5% and 13.5%, respectively (p < 0.001); and 3-year mortality rates of 73.3% and 41.5%, respectively (p < 0.001). After adjustments were made for confounding factors, the infection with MDR and MDR bacteria species were determined to be independent risk factors affecting in-hospital and 3-year mortality.

CONCLUSIONS

MDR bacteria were discovered in patients with more severe bronchiectasis and were independently associated with an increased risk of in-hospital and 3-year mortality. Given our findings, we recommend that clinicians identify patients at risk of MDR bacterial infection and follow the principle of antimicrobial stewardship to prevent the emergence of resistant bacteria among patients with bronchiectasis.

Epidemiology and clinical characteristics of patients with healthcare-acquired multidrug-resistant Gram-negative bacilli: a retrospective study from a tertiary care hospital

The numbers of infections caused by Gram-negative bacteria (GNB) that produce extended-spectrum beta-lactamases (ESBLs) and those that are carbapenem resistant, especially Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae), are increasing, and these infections are becoming a global public health problem. The aim of this study was to assess the prevalence of infections caused by ESBL-producing and carbapenem-resistant Gram-negative bacilli in patients hospitalized at An-Najah National University Hospital in Nablus, Palestine, and to provide healthcare workers with valuable information on the treatment of these infections. A retrospective cross-sectional investigation was conducted at a large tertiary care teaching hospital. The study included patients admitted to the hospital between January and December 2021, from whom ESBL-producing and carbapenem-resistant Gram-negative bacilli were isolated. The patients' clinical and demographic information was obtained from the hospital information system. In addition, information regarding the bacterial isolates and antibiotic resistance was obtained from the hospital's microbiology laboratory. This study included a total of 188 patients-91 males (48.4%) and 97 females (51.6%). The general surgical ward accounted for the highest proportion of infections (30.9%), followed by the surgical ICU (12.2%). The most common infections were caused by ESBL-producing E. coli, which accounted for 62.8% of the cases. Among them, urinary tract infections caused by this microorganism were the most prevalent (44.7% of patients). Over 50% of the patients (54.2%) had a history of antibiotic use, and 77.8% had been hospitalized within the past three months. ESBL-producing E. coli was significantly isolated from blood cultures (p-value = 0.000), and CR-K. pneumoniae was significantly isolated from endotracheal isolates (p-value = 0.001). This study emphasizes the concerning frequency of healthcare-acquired infections caused by ESBL-producing and carbapenem-resistant GNB in a tertiary care hospital. The substantial prevalence of antibiotic resistance presents considerable obstacles to the successful administration of routinely employed antibiotics. The results highlight the immediate need for improved antimicrobial stewardship and the implementation of infection control strategies to reduce the effects of multidrug-resistant GNB on patient well-being and public health.

Multidrug-Resistant Sepsis: A Critical Healthcare Challenge

Sepsis globally accounts for an alarming annual toll of 48.9 million cases, resulting in 11 million deaths, and inflicts an economic burden of approximately USD 38 billion on the United States healthcare system. The rise of multidrug-resistant organisms (MDROs) has elevated the urgency surrounding the management of multidrug-resistant (MDR) sepsis, evolving into a critical global health concern. This review aims to provide a comprehensive overview of the current epidemiology of (MDR) sepsis and its associated healthcare challenges, particularly in critically ill hospitalized patients. Highlighted findings demonstrated the complex nature of (MDR) sepsis pathophysiology and the resulting immune responses, which significantly hinder sepsis treatment. Studies also revealed that aging, antibiotic overuse or abuse, inadequate empiric antibiotic therapy, and underlying comorbidities contribute significantly to recurrent sepsis, thereby leading to septic shock, multi-organ failure, and ultimately immune paralysis, which all contribute to high mortality rates among sepsis patients. Moreover, studies confirmed a correlation between elevated readmission rates and an increased risk of cognitive and organ dysfunction among sepsis patients, amplifying hospital-associated costs. To mitigate the impact of sepsis burden, researchers have directed their efforts towards innovative diagnostic methods like point-of-care testing (POCT) devices for rapid, accurate, and particularly bedside detection of sepsis; however, these methods are currently limited to detecting only a few resistance biomarkers, thus warranting further exploration. Numerous interventions have also been introduced to treat MDR sepsis, including combination therapy with antibiotics from two different classes and precision therapy, which involves personalized treatment strategies tailored to individual needs. Finally, addressing MDR-associated healthcare challenges at regional levels based on local pathogen resistance patterns emerges as a critical strategy for effective sepsis treatment and minimizing adverse effects.

Multidrug-resistant Gram-negative bacterial colonization in patients, carriage by healthcare workers and contamination of hospital environments in Ghana

BACKGROUND

Patients already colonized with multidrug-resistant (MDR) Gram-negative bacteria (GNB) on admission to critical care units may be an important source of transmission of these bacteria in hospitals. We sought to determine the prevalence of MDR GNB colonization in patients, staff and the ward environment and to assess the risk factors for colonization of patients in wards.

METHODS

The study was conducted from April 2021 to July 2021 in a teaching hospital in Ghana. MDR GNB were isolated from rectal, and hand swabs were taken from patients on admission and after 48 h. Swabs from HCW's hands and the ward environment were also taken. Risk factors for colonization with MDR GNB were assessed using univariate and multivariate analysis.

RESULTS

MDR GNB rectal colonization rate among patients was 50.62% on admission and 44.44% after 48 h. MDR GNB were isolated from 6 (5.26%) and 24 (11.54%) of HCW's hand swabs and environmental swabs, respectively. Previous hospitalization (p-value = 0.021, OR, 95% CI= 7.170 (1.345-38.214) was significantly associated with colonization by MDR GNB after 48 h of admission. Age (21-30 years) (p-value = 0.022, OR, 95% CI = 0.103 (0.015-0.716) was significantly identified as a protective factor associated with a reduced risk of rectal MDR GNB colonization.

CONCLUSION

The high colonization of MDR GNB in patients, the carriage of MDR GNB on HCW's hands, and the contamination of hospital environments highlights the need for patient screening and stringent infection prevention and control practices to prevent the spread of MDR GNB in hospitals.

Prostaglandin F2α analogue, bimatoprost ameliorates colistin-induced nephrotoxicity

Colistin (polymyxin E) is an antibiotic that is effective against multidrug-resistant gram-negative bacteria. However, the high incidence of nephrotoxicity caused by colistin limits its clinical use. To identify compounds that might ameliorate colistin-induced nephrotoxicity, we obtained 1707 compounds from the Korea Chemical Bank and used a high-content screening (HCS) imaging-based assay. In this way, we found that bimatoprost (one of prostaglandin F2α analogue) ameliorated colistin-induced nephrotoxicity. To further assess the effects of bimatoprost on colistin-induced nephrotoxicity, we used in vitro and in vivo models. In cultured human proximal tubular cells (HK-2), colistin induced dose-dependent cytotoxicity. The number of terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells, indicative of apoptosis, was higher in colistin-treated cells, but this effect of colistin was ameliorated by cotreatment with bimatoprost. The generation of reactive oxygen species, assessed using 2,7-dichlorodihydrofluorescein diacetate, was less marked in cells treated with both colistin and bimatoprost than in those treated with colistin alone. Female C57BL/6 mice (n = 10 per group) that were intraperitoneally injected with colistin (10 mg/kg/12 hr) for 14 days showed high blood urea nitrogen and serum creatinine concentrations that were reduced by the coadministration of bimatoprost (0.5 mg/kg/12 hr). In addition, kidney injury molecule-1 (KIM1) and Neutrophil gelatinase-associated lipocalin (NGAL) expression also reduced by bimatoprost administration. Further investigation in tubuloid and kidney organoids also showed that bimatoprost attenuated the nephrotoxicity by colistin, showing dose-dependent reducing effect of KIM1 expression. In this study, we have identified bimatoprost, prostaglandin F2α analogue as a drug that ameliorates colistin-induced nephrotoxicity.

Clinical utility of prior positive cultures to optimize empiric antibiotic therapy selection: A cross-sectional analysis

Background

Despite reduced infectious disease mortality and improved survival, infectious diseases continue to pose health threats due to their contagiousness, societal harm, and morbidity. Empiric antibiotic therapy, often prescribed without knowledge of the causative pathogen, faces challenges from rising antibiotic resistance. This study explores the potential of prior positive culture results to guide empiric antibiotic therapy.

Methods

Data from King Abdullah University Hospital (Jan 2014-Dec 2019) included adult patients with recurrent bacterial infections (pneumonia, sepsis, UTIs, wounds). Excluded cases included: mixed infections, transfers, <14 days or >12 months between episodes. The study compared bacterial growth and sensitivity patterns between previous and recent cultures.

Results

The study included 970 episodes from 650 patients, mainly UTIs (60.3%) and gram-negative bacteria (77.9%). The study found that (65.1%) of culture pairs matched. Empirical therapy was accurate in (71.8%) of cases. Further, accuracy of selected empiric antibiotic therapy was significantly predicted (p ​< ​0.001) by: type of infection, type of antibiotics, and concordance with prior microbiologic data. Multivariate logistic analysis showed blood culture as less predictive of pending identity (OR: 0.234, P ​< ​0.001) compared to urine culture; and prior affirmed gram negative bacterial culture was less predictive (OR: 0.606, P ​= ​0.021) compared to gram positive bacterial culture.

Conclusion

This study underscores the potential of prior positive culture results in guiding empiric antibiotic therapy, enhancing accuracy and identity agreement. Future research should explore this approach in different infection contexts and across multiple centers. Reducing the indiscriminate use of broad-spectrum antibiotics is essential to combat antibiotic resistance.

Oral colonization by gram-negative bacilli in patients with hematologic malignancies and solid tumors compared with healthy controls

BACKGROUND

Colonization of the oropharynx with gram-negative bacilli (GNB) is considered a negative prognostic factor in immunocompromised individuals. Hemato-oncologic patients represent a high-risk group due to their immunodeficiencies and associated treatments. This study aimed to determine the rates of oral colonization by GNB, associated factors, and clinical outcomes in patients with hematologic malignancies and solid tumors compared with healthy subjects.

METHODS

We conducted a comparative study of hemato-oncologic patients and healthy subjects from August to October 2022. Swabs were taken from the oral cavity; specimens with GNB were identified and tested for antimicrobial susceptibility.

RESULTS

We included 206 participants (103 hemato-oncologic patients and 103 healthy subjects). Hemato-oncologic patients had higher rates of oral colonization by GNB (34% vs. 17%, P = 0.007) and GNB resistant to third-generation cephalosporins (11.6% vs. 0%, P < 0.001) compared to healthy subjects. Klebsiella spp. was the predominant genus in both groups. The factor associated with oral colonization by GNB was a Charlson index ≥ 3, while ≥ 3 dental visits per year were a protective factor. Regarding colonization by resistant GNB in oncology patients, antibiotic therapy and a Charlson index ≥ 5 were identified as associated factors, while better physical functionality (ECOG ≤ 2) was associated with less colonization. Hemato-oncologic patients colonized with GNB had more 30-day infectious complications (30.5% vs. 2.9%, P = 0.0001) than non-colonized patients.

CONCLUSION

Oral colonization by GNB and resistant GNB are prevalent in cancer patients, especially those with higher scores on the severity scales. Infectious complications occurred more frequently in colonized patients. There is a knowledge gap about dental hygiene practices in hemato-oncologic patients colonized by GNB. Our results suggest that patients' hygienic-dietary habits, especially frequent dental visits, are a protective factor against colonization.

Colistin versus polymyxin B: A pragmatic assessment of renal and neurological adverse effects and effectiveness in multidrug-resistant Gram-negative bacterial infections

OBJECTIVES

Our study aimed to evaluate the real-world data on renal and neurological adverse effects and effectiveness of colistimethate sodium (CMS) and polymyxin B (PMB).

MATERIALS AND METHODS

An observational prospective study was performed on inpatients receiving CMS and PMB for multidrug-resistant Gram-negative bacterial infections. CMS dose was titrated to renal function, and serum creatinine was assessed daily. The incidence of nephrotoxicity, the primary outcome, was evaluated based on an increase in serum creatinine from baseline as well as by the Risk, Injury, Failure, Loss of kidney function, and End-stage renal disease criteria. Neurological adverse effects were assessed based on clinical signs and symptoms, and the causality and severity were assessed by the Naranjo scale and modified Hartwig-Siegel scale, respectively. The effectiveness of polymyxin therapy was ascertained by a composite of microbiological eradication of causative bacteria and achievement of clinical cure. Thirty-day all-cause mortality was also determined.

RESULTS

Between CMS and PMB, the incidence of nephrotoxicity (59.3% vs. 55.6%, P = 0.653) or neurotoxicity (8.3% vs. 5.6%, P = 0.525) did not significantly differ. However, reversal of nephrotoxicity was significantly more with patients receiving CMS than PMB (48.4% vs. 23.3%, P = 0.021). Favorable clinical outcomes (67.6% vs. 37%, P < 0.001) and microbiological eradication of causative bacteria (73.1% vs. 46.3%, P = 0.001) were significantly more with CMS than PMB. Patients treated with CMS had lower all-cause mortality than those with PMB treatment (19.4% vs. 42.6%, P = 0.002).

CONCLUSION

There is no significant difference in the incidence of renal and neurotoxic adverse effects between CMS and PMB when CMS is administered following renal dose modification. CMS shows better effectiveness and lower mortality compared to PMB.

Prognostic Trends and Current Challenges in Candidemia: A Comparative Analysis of Two Multicenter Cohorts within the Past Decade

Candidemia remains a major public health challenge due to its high mortality rates, especially in developing countries. Monitoring epidemiological trends may provide insights for better clinical outcomes. This study aimed to describe trends in the epidemiology, therapeutic practices, and mortality in candidemia through a retrospective comparative analysis between two surveillance cohorts of all candidemic adults at eleven tertiary hospitals in Brazil, from 2010-2011 (Period I) versus 2017-2018 (Period II). A total of 616 cases were diagnosed, with 247 being from Period II. These patients were more likely to have three or more coexisting comorbidities [72 (29.1%) vs. 60 (16.3%), p < 0.001], had a prior history of in-hospital admissions more often [102 (40.3%) vs. 79 (21.4%), p = 0.001], and presented with candidemia earlier after admission, within 15 days (0-328) vs. 19 (0-188), p = 0.01. Echinocandins were more frequently prescribed [102 (41.3%) vs. 50 (13.6%), p = 0.001], but time to antifungal initiation [2 days (0-14) vs. 2 (0-13), p = 0.369] and CVC removal within 48 h [90/185 (48.6%) vs. 148/319 (46.4%), p = 0.644] remained unchanged. Additionally, many patients went untreated in both periods I and II [87 (23.6%) vs. 43 (17.4%), p = 0.07], respectively. Unfortunately, no improvements in mortality rates at 14 days [123 (33.6%) vs. 93 (37.7%), p = 0.343] or at 30 days [188 (51.4%) vs. 120 (48.6%), p = 0.511] were observed. In conclusion, mortality rates remain exceedingly high despite therapeutic advances, probably associated with an increase in patients' complexity and suboptimal therapeutic interventions. Management strategies should be tailored to suit epidemiological changes, expedite diagnosis to reduce the number of untreated eligible patients and guarantee early antifungal initiation and source control.

Genomic Characterization of Multidrug-Resistant Extended Spectrum β-Lactamase-Producing Klebsiella pneumoniae from Clinical Samples of a Tertiary Hospital in South Kivu Province, Eastern Democratic Republic of Congo

Multidrug-resistant (MDR) and extended spectrum β-lactamase (ESBL)-producing extra-intestinal K. pneumoniae are associated with increased morbidity and mortality. This study aimed to characterize the resistance and virulence profiles of extra-intestinal MDR ESBL-producing K. pneumoniae associated with infections at a tertiary hospital in South-Kivu province, DRC. Whole-genome sequencing (WGS) was carried out on 37 K. pneumoniae isolates displaying MDR and ESBL-producing phenotype. The assembled genomes were analysed for phylogeny, virulence factors and antimicrobial resistance genes (ARG) determinants. These isolates were compared to sub-Saharan counterparts. K. pneumoniae isolates displayed a high genetic variability with up to 16 sequence types (ST). AMR was widespread against β-lactamases (including third and fourth-generation cephalosporins, but not carbapenems), aminoglycosides, ciprofloxacin, tetracycline, erythromycin, nitrofurantoin, and cotrimoxazole. The bla_CTX-M-15 gene was the most common β-lactamase gene among K. pneumoniae isolates. No carbapenemase gene was found. ARG for aminoglycosides, quinolones, phenicols, tetracyclines, sulfonamides, nitrofurantoin were widely distributed among the isolates. Nine isolates had the colistin-resistant R256G substitution in the pmrB efflux pump gene without displaying reduced susceptibility to colistin. Despite carrying virulence genes, none had hypervirulence genes. Our results highlight the genetic diversity of MDR ESBL-producing K. pneumoniae isolates and underscore the importance of monitoring simultaneously the evolution of phenotypic and genotypic AMR in Bukavu and DRC, while calling for caution in administering colistin and carbapenem to patients.

In-hospital mortality and one-year survival of critically ill patients with cancer colonized or not with carbapenem-resistant gram-negative bacteria or vancomycin-resistant enterococci: an observational study

BACKGROUND

Patients with cancer are at risk of multidrug-resistant bacteria colonization, but association of colonization with in-hospital mortality and one-year survival has not been established in critically ill patients with cancer.

METHODS

Using logistic and Cox-regression analyses adjusted for confounders, in adult patients admitted at intensive care unit (ICU) with active cancer, we evaluate the association of colonization by carbapenem-resistant Gram-negative bacteria or vancomycin-resistant enterococci with in-hospital mortality and one-year survival.

RESULTS

We included 714 patients and among them 140 were colonized (19.6%). Colonized patients more frequently came from ward, had longer hospital length of stay before ICU admission, had unplanned ICU admission, had worse performance status, higher predicted mortality upon ICU admission, and more hematological malignancies than patients without colonization. None of the patients presented conversion of colonization to infection by the same bacteria during hospital stay, but 20.7% presented conversion to infection after hospital discharge. Colonized patients had a higher in-hospital mortality compared to patients without colonization (44.3 vs. 33.4%; p < 0.01), but adjusting for confounders, colonization was not associated with in-hospital mortality [Odds ratio = 1.03 (0.77-1.99)]. Additionally, adjusting for confounders, colonization was not associated with one-year survival [Hazard ratio = 1.10 (0.87-1.40)].

CONCLUSIONS

Adult critically ill patients with active cancer and colonized by carbapenem-resistant Gram-negative bacteria or vancomycin-resistant enterococci active cancer have a worse health status compared to patients without colonization. However, adjusting for confounders, colonization by carbapenem-resistant Gram-negative bacteria or vancomycin-resistant enterococci are not associated with in-hospital mortality and one-year survival.

How Does Hospital Microbiota Contribute to Healthcare-Associated Infections?

Healthcare-associated infections (HAIs) are still a global public health concern, associated with high mortality and increased by the phenomenon of antimicrobial resistance. Causative agents of HAIs are commonly found in the hospital environment and are monitored in epidemiological surveillance programs; however, the hospital environment is a potential reservoir for pathogenic microbial strains where microorganisms may persist on medical equipment surfaces, on the environment surrounding patients, and on corporal surfaces of patients and healthcare workers (HCWs). The characterization of hospital microbiota may provide knowledge regarding the relatedness between commensal and pathogenic microorganisms, their role in HAIs development, and the environmental conditions that favor its proliferation. This information may contribute to the effective control of the dissemination of pathogens and to improve infection control programs. In this review, we describe evidence of the contribution of hospital microbiota to HAI development and the role of environmental factors, antimicrobial resistance, and virulence factors of the microbial community in persistence on hospital surfaces.

Mechanobactericidal, Gold Nanostar Hydrogel-Based Bandage for Bacteria-Infected Skin Wound Healing

The emergence of multidrug resistant (MDR) microorganisms has led to the development of alternative approaches for providing relief from microbial attacks. The mechano-bactericidal action as a substitute for antimicrobials has become the focus of intensive research. In this work, nanostructure-conjugated hydrogel are explored as a flexible dressing against Staphylococcus aureus (S. aureus)-infected skin wounds. Herein gold nanostars (AuNst) with spike lengths reaching 120 nm are probed for antibacterial action. The bacterial killing of >95% is observed for Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli), while up to 60% for Gram-positive S. aureus. AuNst conjugated hydrogel (AuNst₁₂₀@H) reduced >80% colonies of P. aeruginosa and E. coli. In comparison, around 35.4% reduction of colonies are obtained for S. aureus. The viability assay confirmed the presence of about 85% of living NIH-3T3 cells when grown with hydrogels. An animal wound model is also developed to assess the efficiency of AuNst₁₂₀@H. A significant reduction in wound size is observed on the 10th day in AuNst₁₂₀@H treated animals with fully formed epidermal layers, hair follicles, new blood vessels, and arrector muscles. These findings suggest that novel dressing materials can be developed with antimicrobial nanotextured surfaces.

The role of the microbiology laboratory in the diagnosis of multidrug-resistant Gram-negative bacilli infections. The importance of the determination of resistance mechanisms

Early diagnosis and treatment has an important impact on the morbidity and mortality of infections caused by multidrug-resistant bacteria. Multidrug-resistant gram-negative bacilli (MR-GNB) constitute the main current threat in hospitals and especially in intensive care units (ICU). The role of the microbiology laboratory is essential in providing a rapid and effective response. This review updates the microbiology laboratory procedures for the rapid detection of BGN-MR and its resistance determinants. The role of the laboratory in the surveillance and control of outbreaks caused by these bacteria, including typing techniques, is also studied. The importance of providing standardized resistance maps that allow knowing the epidemiological situation of the different units is emphasized. Finally, the importance of effective communication systems for the transmission of results and decision making in the management of patients infected by BGN-MR is reviewed.

Gram-negative multidrug-resistant organisms were dominant in neurorehabilitation ward patients in a general hospital in southwest China

This study aimed to investigate the prevalence of and risk factors for multidrug-resistant organism (MDRO) infection in the rehabilitation ward of a general hospital in Southwest China. We analyzed rehabilitation patients with nosocomial infections caused by MDROs from June 2016 to June 2020. MDRO infection pathogens and associated antibiotic resistance were calculated. Possible risk factors for MDRO-related infection in the neurorehabilitation ward were analyzed using chi-square, and logistic regression. A total of 112 strains of MDRO were found positive from 96 patients. The MDRO test-positive rate was 16.70% (96/575). Ninety-five MDRO strains were detected in sputum, of which 84.82% (95/112) were gram-negative bacteria. Acinetobacter baumannii (A. Baumannii), Pseudomonas aeruginosa (P. aeruginosa), and Klebsiella pneumonia (K. pneumonia) were the most frequently isolated MDRO strains. The logistic regression model and multifactorial analysis showed that long-term (≥ 7 days) antibiotic use (OR 6.901), history of tracheotomy (OR 4.458), and a low albumin level (< 40 g/L) (OR 2.749) were independent risk factors for the development of MDRO infection in patients in the rehabilitation ward (all P < 0.05). Gram-negative MRDOs were dominant in rehabilitation ward patients. Low albumin, history of a tracheostomy, and long-term use of antibiotics were independent risk factors for MRDO infection and are worthy of attention.

Rectal colonization by resistant bacteria increases the risk of infection by the colonizing strain in critically ill patients with cirrhosis

BACKGROUND & AIMS

It remains unclear whether rectal colonization with multidrug-resistant organisms (MDROs) is prevalent and predisposes to infections by the same pathogens in patients with cirrhosis.

METHODS

Two series of critically ill patients were evaluated. In the Barcelona cohort, 486 consecutive patients were prospectively evaluated, 129 with and 357 without cirrhosis (2015-2016). Rectal swabs were performed at admission and weekly thereafter (until intensive care unit [ICU] discharge) to detect MDRO colonization. Risk factors for colonization and infection by MDROs were evaluated. A retrospective cohort from Frankfurt (421 patients with cirrhosis; 2010-2018) was investigated to evaluate MDRO rectal colonization in another epidemiological scenario.

RESULTS

In the Barcelona cohort, 159 patients were colonized by MDROs (32.7%), 102 (64.2%) at admission and 57 (35.8%) during follow-up. Patients with cirrhosis showed higher rates of rectal colonization at admission than those without cirrhosis (28.7% vs. 18.2%, p = 0.01) but similar colonization rates during ICU stay. Extended-spectrum beta-lactamase-Enterobacterales were the most frequent MDROs isolated in both groups. Colonization by MDROs independently increased the risk of infection by MDROs at admission and during follow-up. Risk of new infection by the colonizing strain was also significantly increased in patients with (hazard ratio [HR] 7.41) and without (HR 5.65) cirrhosis. Rectal colonization by MDROs was also highly prevalent in Frankfurt (n = 198; 47%; 131 at admission [66.2%] and 67 [33.8%] during follow-up), with vancomycin-resistant enterococci being the most frequent colonizing organism. Rectal colonization by MDROs was also associated with an increased risk of infection by MDROs in this cohort. Infections occurring in MDR carriers were mainly caused by the colonizing strain.

CONCLUSION

Rectal colonization by MDROs is extremely frequent in critically ill patients with cirrhosis. Colonization increases the risk of infection by the colonizing resistant strain.

LAY SUMMARY

Rectal colonization by multidrug-resistant organisms (MDROs) is a prevalent problem in patients with cirrhosis requiring critical care. The pattern of colonizing bacteria is heterogeneous with relevant differences between centers. Colonization by MDROs is associated with increased risk of infection by the colonizing bacteria in the short term. This finding suggests that colonization data could be used to guide empirical antibiotic therapy and de-escalation policies in patients with cirrhosis.

High Fecal Carriage of Multidrug Resistant Bacteria in the Community among Children in Northwestern Tanzania

Colonization of multidrug resistant (MDR) bacteria is associated with subsequent invasive infections in children with comorbidities. This study aimed to determine the resistance profile and factors associated with MDR pathogen colonization among HIV−and HIV+ children below five years of age in Mwanza, Tanzania. A total of 399 (HIV− 255 and HIV+ 144) children were enrolled and investigated for the presence of MDR bacteria. The median [IQR] age of children was 19 (10–36) months. Out of 27 Staphylococcus aureus colonizing the nasal cavity, 16 (59.5%) were methicillin resistant while 132/278 (47.2%) of Enterobacteriaceae from rectal swabs were resistant to third generation cephalosporins, with 69.7% (92/132) exhibiting extended spectrum beta lactamase (ESBL) phenotypes. The proportion of resistance to gentamicin, amoxicillin/clavulanic acid and meropenem were significantly higher among HIV+ than HIV− children. A history of antibiotic use in the last month OR 2.62 [1.1, 6.9] (p = 0.04) and history of a relative admitted from the same household in the past three months OR 3.73 [1.1, 13.2] (p = 0.03) independently predicted ESBL rectal colonization. HIV+ children had significantly more fecal carriage of isolates resistant to uncommonly used antibiotics. There is a need to strengthen antimicrobial stewardship and Infection Prevention and Control (IPC) programs to prevent the emergence and spread of MDR pathogens in children.

Epidemiology of Extended-Spectrum Beta-Lactamase and Carbapenemase-Producing Enterobacterales in the Greater Mekong Subregion: A Systematic-Review and Meta-Analysis of Risk Factors Associated With Extended-Spectrum Beta-Lactamase and Carbapenemase Isolation

Background: Despite the rapid spread of extended-spectrum beta-lactamase (ESBL) producing-Enterobacterales (ESBL-E) and carbapenemase-producing Enterobacterales (CPE), little is known about the extent of their prevalence in the Greater Mekong Subregion (GMS). In this systematic review, we aimed to determine the epidemiology of ESBL-E and CPE in clinically significant Enterobacterales: Escherichia coli and Klebsiella pneumoniae from the GMS (comprising of Cambodia, Laos, Myanmar, Thailand, Vietnam and Yunnan province and Guangxi Zhuang region of China). Methods: Following a list of search terms adapted to subject headings, we systematically searched databases: Medline, EMBASE, Scopus and Web of Science for articles published on and before October 20th, 2020. The search string consisted of the bacterial names, methods involved in detecting drug-resistance phenotype and genotype, GMS countries, and ESBL and carbapenemase detection as the outcomes. Meta-analyses of the association between the isolation of ESBL from human clinical and non-clinical specimens were performed using the "METAN" function in STATA 14. Results: One hundred and thirty-nine studies were included from a total of 1,513 identified studies. Despite the heterogeneity in study methods, analyzing the prevalence proportions on log-linear model scale for ESBL producing-E. coli showed a trend that increased by 13.2% (95%CI: 6.1-20.2) in clinical blood specimens, 8.1% (95%CI: 1.7-14.4) in all clinical specimens and 17.7% (95%CI: 4.9-30.4) increase in carriage specimens. Under the log-linear model assumption, no significant trend over time was found for ESBL producing K. pneumoniae and ESBL-E specimens. CPE was reported in clinical studies and carriage studies past 2010, however a trend could not be determined because of the small dataset. Twelve studies were included in the meta-analysis of risk factors associated with isolation of ESBL. Recent antibiotic exposure was the most studied variable and showed a significant positive association with ESBL-E isolation (pooled OR: 2.9, 95%CI: 2.3-3.8) followed by chronic kidney disease (pooled OR: 4.7, 95%CI: 1.8-11.9), and other co-morbidities (pooled OR: 1.6, 95%CI: 1.2-2.9). Conclusion: Data from GMS is heterogeneous with significant data-gaps, especially in community settings from Laos, Myanmar, Cambodia and Yunnan and Guangxi provinces of China. Collaborative work standardizing the methodology of studies will aid in better monitoring, surveillance and evaluation of interventions across the GMS.

High Acquisition Rate of Gram-Negative Multi-Drug Resistant Organism Colonization During Hospitalization: A Perspective from a High Endemic Setting

Objective

The aim of the study was to compare the rate of gram-negative multi-drug resistant organism (GN-MDRO) colonization at admission and during hospitalization and to describe the strains and antibiotic resistance genes acquired during hospitalization.

Methods

Rectal swabs were collected from patients hospitalized at the National Trauma Center (NTC), Mongolia, at the time of admission and after 14 days of hospitalization as has been detailed on our previous study. GN-MDRO antibiotic resistance was determined using EUCAST standards, and resistance genes were detected using multiplex PCR.

Results

A total of 158 patients were screened, and baseline colonization rate at admission was 29.1% (46/158). The rate went up to 69.9% (110/158) after 14 days of hospitalization (p<0.001). Of all participants, 74 patients (46.8%) screened GN-MDRO negative at admission acquired colonization by day 14. Other 36 patients (22.8%) maintained colonization that was screened positive at both time points. Only 38 patients (24.0%) remained free of GN-MDRO during hospitalization. There was a difference in GN-MDRO acquisition between these groups. Patients who were negative at admission acquired up to 3 GN-MDRO species, and there were 10 different species isolated. Reversely, patients who were screened positive at both time points had fairly homogenous isolates; up to 5 species of Enterobacterales were identified at admission and day 14 hospitalization. Overall, Enterobacterales were the dominant colonizers (61.4%, 97/158), and all Enterobacterales were resistant to cefotaxime as CTX-M resistance was our inclusion criteria.

Conclusion

GN-MDRO baseline colonization rate on admission was high and, alarmingly, doubled during hospitalization in the study area. Enterobacterales was the predominant colonizer and was highly resistant to 3rd generation cephalosporin. This data supports a need for an improved infection control policy including routine surveillance of the GN-MDROs and improved antibiotic stewardship program.

Geographical information system and spatial-temporal statistics for monitoring infectious agents in hospital: a model using Klebsiella pneumoniae complex

Background

The emergence and spread of antimicrobial resistance and infectious agents have challenged hospitals in recent decades. Our aim was to investigate the circulation of target infectious agents using Geographic Information System (GIS) and spatial–temporal statistics to improve surveillance and control of healthcare-associated infection and of antimicrobial resistance (AMR), using Klebsiella pneumoniae complex as a model.

Methods

A retrospective study carried out in a 450-bed federal, tertiary hospital, located in Rio de Janeiro. All isolates of K. pneumoniae complex from clinical and surveillance cultures of hospitalized patients between 2014 and 2016, identified by the use of Vitek-2 system (BioMérieux), were extracted from the hospital's microbiology laboratory database. A basic scaled map of the hospital’s physical structure was created in AutoCAD and converted to QGis software (version 2.18). Thereafter, bacteria according to resistance profiles and patients with carbapenem-resistant K. pneumoniae (CRKp) complex were georeferenced by intensive and nonintensive care wards. Space–time permutation probability scan tests were used for cluster signals detection.

Results

Of the total 759 studied isolates, a significant increase in the resistance profile of K. pneumoniae complex was detected during the studied years. We also identified two space–time clusters affecting adult and paediatric patients harbouring CRKp complex on different floors, unnoticed by regular antimicrobial resistance surveillance.

Conclusions

In-hospital GIS with space–time statistical analysis can be applied in hospitals. This spatial methodology has the potential to expand and facilitate early detection of hospital outbreaks and may become a new tool in combating AMR or hospital-acquired infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-00944-5.

Long-term outcome and risk factors for late mortality in Gram-negative bacteraemia: a retrospective cohort study

OBJECTIVES

The long-term outcomes of patients following Gram-negative bacteraemia (GNB) are poorly understood. Here we describe a cohort of patients with GNB over a 2-year period and determine factors associated with late mortality (death between Days 31 and 365 after detection of bacteraemia).

METHODS

This was a single-centre, retrospective, observational cohort study of 789 patients with confirmed Escherichia coli, Klebsiella spp. or Pseudomonas aeruginosa bacteraemia with a follow-up of 1 year. Multivariable survival analysis was used to determine risk factors for late mortality in patients who survived the initial 30-day period of infection.

RESULTS

Overall, 1-year all-cause mortality was 36.2%, with 18.1% of patients dying within 30 days and 18.1% of patients suffering late mortality. An adverse antimicrobial resistance profile [hazard ratio (HR) = 1.095 per any additional antimicrobial category, 95% confidence interval (CI) 1.018-1.178; P = 0.014] and infection with P. aeruginosa (HR = 2.08, 95% CI 1.11-3.88; P = 0.022) were independent predictors of late mortality. Other significant factors included Charlson comorbidity index and length of hospitalisation after the index blood culture.

CONCLUSION

Patients with GNB have a poor long-term prognosis. Risk factors for greater mortality at 1 year include co-morbidity, length of hospitalisation, and infecting organism and its resistance profile.

A narrative review on antimicrobial therapy in septic shock: updates and controversies

PURPOSE OF REVIEW

Antibiotics are an essential treatment for septic shock. This review provides an overview of the key issues in antimicrobial therapy for septic shock. We include a summary of available evidence with an emphasis on data published in the last few years.

RECENT FINDINGS

We examine apparently contradictory data supporting the importance of minimizing time to antimicrobial therapy in sepsis, discuss approaches to choosing appropriate antibiotics, and review the importance and challenges presented by antimicrobial dosing. Lastly, we evaluate the evolving concepts of de-escalation, and optimization of the duration of antimicrobials.

SUMMARY

The topics discussed in this review provide background to key clinical decisions in antimicrobial therapy for septic shock: timing, antibiotic choice, dosage, de-escalation, and duration. Although acknowledging some controversy, antimicrobial therapy in septic shock should be delivered early, be of the adequate spectrum, appropriately and individually dosed, rationalized when possible, and of minimal effective duration.

The influence of antibiotics on transitory resistome during gut colonization with CTX-M-15 and OXA-162 producing Klebsiella pneumoniae ST15

Great efforts have been made to limit the transmission of carbapenemase-producing Enterobacteriaceae (CPE), however, the intestinal reservoir of these strains and its modulation by various antibiotics remain largely unexplored. Our aim was to assess the effects of antibiotic administration (ampicillin, ceftazidime, ciprofloxacin) on the establishment and elimination of intestinal colonization with a CTX-M-15 ESBL and OXA-162 carbapenemase producing Klebsiella pneumoniae ST15 (KP5825) in a murine (C57BL/6 male mice) model. Whole genome sequencing of KP5825 strain was performed on an Illumina MiSeq platform. Conjugation assays were carried out by broth mating method. In colonization experiments, 5 × 106 CFU of KP5825 was administered to the animals by orogastric gavage, and antibiotics were administered in their drinking water for two weeks and were changed every day. The gut colonization rates with KP5825 were assessed by cultivation and qPCR. In each of the stool samples, the gene copy number of blaOXA-162 and blaCTX-M-15 were determined by qPCR. Antibiotic concentrations in the stool were determined by high pressure liquid chromatography and a bioanalytical method. The KP5825 contained four different plasmid replicon types, namely IncFII(K), IncL, IncFIB and ColpVC. IncL (containing the blaOXA-162 resistance gene within a Tn1991.2 genetic element) and IncFII(K) (containing the blaCTX-M-15 resistance gene) plasmids were successfully conjugated. During ampicillin and ceftazidime treatments, colonization rate of KP5825 increased, while, ciprofloxacin treatments in both concentrations (0.1 g/L and 0.5 g/L) led to significantly decreased colonization rates. The gene copy number blaOXA-162 correlated with K. pneumoniae in vivo, while a major elevation was observed in the copy number of blaCTX-M-15 from the first day to the fifteenth day in the 0.5 g/L dose ceftazidime treatment group. Our results demonstrate that commonly used antibiotics may have diverse impacts on the colonization rates of intestinally-carried CPE, in addition to affecting the gene copy number of their resistance genes, thus facilitating their stable persistance and dissemination.

Colonization Dynamics of Multidrug-Resistant Klebsiella pneumoniae Are Dictated by Microbiota-Cluster Group Behavior over Individual Antibiotic Susceptibility: A Metataxonomic Analysis

Gastrointestinal carriage of multidrug-resistant (MDR) bacteria is one of the main risk factors for developing serious, difficult-to-treat infections. Given that there is currently no all-round solution to eliminate colonization with MDR bacteria, it is particularly important to understand the dynamic process of colonization to aid the development of novel decolonization strategies. The aim of our present study was to perform metataxonomic analyses of gut microbiota dynamics during colonization with an extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Klebsiella pneumoniae (ECKP) strain in mice; additionally, to ascertain the effects of antibiotic administration (ampicillin, ceftazidime, and ciprofloxacin) on the establishment and elimination of ECKP intestinal colonization. We have found that the phyla Bacteroidetes and Firmicutes were most dominant in all of the treatment groups; however, Bacteroidetes was more common in the groups treated with antibiotics compared to the control group. Significant differences were observed among the different antibiotic-treated groups in beta but not alpha diversity, implying that the difference is the relative abundance of some bacterial community members. Bacteria from the Lachnospiraceae family (including Agathobacter, Anaerostipes, Lachnoclostridium 11308, Lachnospiraceae UCG-004, Lachnospiraceae NK3A20 group 11318, Lachnospiraceae NK4A136 group 11319, Roseburia, and Tyzzerella) showed an inverse relationship with the carriage rate of the ECKP strain, whereas members of Enterobacteriaceae and the ECKP strain have shown a correlational relationship. Our results suggest that the composition of the microbial community plays a primary role in the MDR-colonization rate, whereas the antibiotic susceptibility of individual MDR strains affects this process to a lesser extent. Distinct bacterial families have associated into microbial clusters, collecting taxonomically close species to produce survival benefits in the gut. These associations do not develop at random, as they may be attributed to the presence of specific metabolomic networks. A new concept should be introduced in designing future endeavors for MDR decolonization, supplemented by knowledge of the composition of the host bacterial community and the identification of bacterial clusters capable of suppressing or enhancing the invader species.

Staphylococcus aureus colonization increases the risk of bacteremia in hemodialysis patients: a molecular epidemiology approach with time-dependent analysis

BACKGROUND

Bacteremia is the second cause of death in hemodialysis patients and colonization may be a risk factor. We analyzed the association between Staphylococcus aureus or multidrug-resistant Gram-negative bacteria colonization and bacteremia in hemodialysis patients.

METHODS

A prospective cohort study was conducted. Colonization status was determined at baseline, 2, and 6 months later. The time-to-first-bacteremia was analyzed using the baseline status and time-dependent nature of colonization. The recurrence of bacteremia given colonization status was evaluated using a Poisson regression model. The genetic relatedness between isolates that colonized and caused bacteremia were established by molecular typing methods.

RESULTS

Seventy-one patients developed bacteremia over the course of follow-up, with the majority of cases being caused by S aureus (n = 28; 39.4%) and only three caused by multidrug-resistant Gram-negative bacteria. S aureus colonization was associated with an increased risk of bacteremia in time-dependent analysis (HR:4.64; 95%CI: 1.72-12.53) and with recurrence of infection in Poisson model (IRR:5.90, 95%CI: 2.29-15.16). Molecular methods revealed that 77.8% of patients with S aureus bacteremia were colonized with the same strain that caused the infection.

CONCLUSIONS

S aureus is a cause of endogenous infection in hemodialysis patients. Colonization is associated with both time-to-first-bacteremia and the recurrence of infection. The prompt identification of colonized patients and the evaluation of decolonization protocols are needed.

Prevalence, distribution and antimicrobial susceptibility pattern of bacterial isolates from a tertiary Hospital in Malawi

Background

Bacterial infections are a significant cause of sickness and death in sub-Saharan Africa. This study aimed at establishing the prevalence, distribution and antimicrobial susceptibility pattern of major bacterial isolates from patients accessing medical care at a tertiary hospital in Malawi.

Methods

We retrospectively reviewed bacteria culture and antimicrobial susceptibility records for 4617 patients from 2002 to 2014 at Mzuzu Central Hospital (MCH). No inclusion and exclusion criteria were followed. Data was analysed using excel (Microsoft office, USA) and GraphPad prism 7 software programs.

Results

The most prevalent isolates were S. aureus (34.7%, n = 783), Klebsiella species (17.4%, n = 393) and Proteus species (11.4%, n = 256). Most microorganisms were isolated from adults (88.3%, n = 3889) and pus was the main source (69.3%, n = 1224). S. pneumoniae was predominantly isolated from cerebrospinal fluid (60.3%, n = 44) largely collected from children (88.2%, n = 64). Overall, most bacteria exhibited high resistance to all regularly used antimicrobials excluding ciprofloxacin.

Conclusions

Our report demonstrates an increase in bacterial infection burden in sites other than blood stream and subsequent increase in prevalence of antimicrobial resistance for all major isolates. Creating an epidemiological survey unit at MCH will be essential to help inform better treatment and management options for patients with bacterial infections.

High intermittent colonization by diverse clones of β-lactam-resistant Gram-negative bacilli suggests an excessive antibiotic use and different sources of transmission in haemodialysis patients

BACKGROUND

The spread of β-lactam-resistant Gram-negative bacilli (GNB) is a topic of worldwide concern; however, knowledge about colonization by these bacteria in haemodialysis patients is limited.

AIM

To analyse the dynamics and factors associated with colonization by β-lactam-resistant GNB in a dialysis centre.

METHODS

A longitudinal study was conducted. Stool samples were collected for each patient to evaluate extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Gram-negative bacilli. Colonization screens were performed at three time-points and then classified as absent, intermittent, or persistent. Molecular typing included enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction, pulsed-field gel electrophoresis (PFGE), and multi-locus sequence typing (MLST). Clinical information was obtained from medical records and personal interview. A generalized estimating equations model was performed to determinate factors associated with the colonization.

FINDINGS

A total of 210 patients were included. ESBL-producing and carbapenem-resistant GNB colonization reached 41.2% and 11.5%, respectively. Most patients were intermittent carriers with frequencies of 73.9% and 92.95% for each bacteria group. The most frequent ESBL was CTX-M-G1, while the most common carbapenemase was KPC. ERIC-PCR and PFGE revealed high genetic diversity among strains and the Escherichia coli clone ST131 was the most important by MLST. Fluoroquinolone use (odds ratio: 3.13; 95% confidence interval: 1.03-9.44; P [cap] = 0.043) and chronic obstructive lung disease (odds ratio: 3.53; 1.42-8.74; P = 0.006) were associated with ESBL-producing GNB colonization.

CONCLUSION

Our findings indicate a high intermittent colonization by diverse clones of β-lactam-resistant GNB in haemodialysis patients. It suggests excessive antibiotic pressure that favours the acquisition of bacteria with diverse genetic profiles and different transmission sources.

Dynamics of colonization in patients with health care-associated infections at step-down care units from a tertiary care hospital in Mexico

BACKGROUND

Patient colonization has been suggested as a risk factor in hospital-associated infections (HAI) development, which are of the most frequent complications in hospitals.

OBJECTIVE

To examine the colonization process and possible transmission routes of HAI-causative agents in step-down care unit (SDCU) patients.

METHODS

Patients admitted to SDCU within 48 hours of admission that had no evidence of infection present, nurse health care workers (HCWs), and relatives of infected patients were included. Participants were sampled and cultured at different times in different body surfaces. Environmental surfaces and medical devices were also sampled. Antimicrobial susceptibility and clonal relatedness were determined in selected HAI-causative agents, environmental, nurse HCWs, and patient isolates.

RESULTS

A total of 2,735 isolates corresponding to 126 species were identified. Of the 11 patients included, 8 developed 1-3 HAIs (14 isolates recovered as HAI-causative agents). Acinetobacter baumannii (36% of infections) was distributed in clone A (n = 1), B (n = 3), and F (n = 1); Klebsiella pneumoniae (29%) in clones A (n = 2) and B (n = 1) and Enterobacter cloacae (7%) in one clone A. Causative agents were progressively recovered from environmental surfaces and medical devices before and after HAI onset.

CONCLUSIONS

Highly related strains were recovered from environmental surfaces, patients, and nurse HCWs before and after HAI outcome. This is a first step to examine colonization process in SDCU settings and provides a base for further studies to understand colonization dynamics and the role of patients' relatives and nurse HCWs in organism transmission in the SDCU.

Sepsis in surgical inpatients: under-recognised but with significant consequences

BACKGROUND

The true incidence of sepsis in surgical cohorts in Ireland remains unclear. According to inpatient audits, patients in surgical diagnostic groups (DRG) who developed sepsis had a longer length of stay and higher mortality rate compared with medical DRG patients who developed sepsis.

AIMS

We investigated sepsis incidence on a general surgical ward to identify risk factors and strategies to improve management.

METHODS

Demographics, admission and discharge details, infection risk factors, infection, and sepsis were studied prospectively on a surgical ward in July 2018.

RESULTS

The mean age of 164 patients was 60.5 years (range 18-93 years), 107 (65.2%) were admitted electively, 16 (9.8%) were colonised with a multidrug-resistant organism (MDRO), and 30 (18.3%) were classified as frail on admission. Twelve (7.3%) developed sepsis (ward sepsis rate 118.2/10,000 bed days used). 'Sepsis' was documented in six cases and the national sepsis screening form used in four patients. Patients with sepsis were three times as likely to be MDRO-colonised (OR 3.56; 95% CI = 0.86-14.82; p = 0.065) or frail (OR 3.63; 95% CI = 1.07-12.35; p = 0.03), four times as likely to be an inpatient at the end of the study (OR 4.22, 96% CI 1.23-14.49; p = 0.01), and three times as likely to be readmitted (OR 3.46, 95% CI 1.02-11.76; p = 0.03).

CONCLUSION

Sepsis was under-documented, and barriers exist with use of the national sepsis screening form. Frailty, which is a sepsis risk factor, should be assessed pre-operatively to maximise prevention.

Risk factor for intestinal carriage of carbapenem-resistant Acinetobacter baumannii and the impact on subsequent infection among patients in an intensive care unit: an observational study

OBJECTIVES

To assess the incidence and the impact of carbapenem-resistant Acinetobacter baumannii (CRAB) intestinal carriage on subsequent CRAB infection and to study risk factors of acquiring CRAB intestinal carriage among patients in intensive care unit (ICU).

DESIGN

Observational study including a case-control study and a retrospective cohort study.

SETTING

A 50-bed general ICU of a university hospital, China.

METHODS

From May 2017 to April 2018, an observational study was conducted in a 50-bed general ICU of a university hospital in China. Rectal swabs were collected from ICU patients on admission and thereafter weekly. A case-control study was performed to analyse risk factors of the acquisition of CRAB intestinal carriage in ICU using multiple logistic regression. A retrospective cohort study was performed to address whether intestinal CRAB carriage could lead to an increased likelihood of subsequent CRAB infection using subdistribution hazard model regarding death in the ICU as a competing risk event.

RESULTS

CRAB intestinal carriage was detected in 6.87% (66/961; 95% CI 5.27% to 8.47%) of patients on ICU admission, whereas 11.97% (115/961; 95% CI 9.91% to 14.02%) of patients acquired CRAB intestinal carriage during the ICU stay. Pancreatitis (OR 2.16, 95% CI 1.28 to 3.67), haematological disease (OR 2.26, 95% CI 1.42 to 3.58), gastric tube feeding (OR 3.35, 95% CI 2.03 to 5.51) and use of carbapenems (OR 1.84, 95% CI 1.11 to 3.07) were independent risk factors for acquiring CRAB intestinal carriage. The incidence of subsequent CRAB infection was 2.24-fold in patients with CRAB intestinal carriage compared with that in patients without (95% CI 1.48 to 3.39, p<0.001).

CONCLUSION

More patients acquired CRAB intestinal carriage during their ICU stay than had on admission. Severity of illness, acute pancreatitis, tube feeding and use of carbapenems were independent risk factors of acquisition of CRAB intestinal carriage. Patients with CRAB intestinal carriage are more likely to develop CRAB infection.

Approach to the Treatment of Patients with Serious Multidrug-Resistant Pseudomonas aeruginosa Infections

Multidrug resistance(MDR) among Pseudomonas aeruginosa (PSA) isolates presents a significant clinical challenge and can substantially complicate the approach to selection of optimal antibiotic therapy. This review addresses major considerations in antibiotic selection for patients with suspected or documented serious MDR-PSA infections. Common mechanisms contributing to MDR among clinical PSA isolates are summarized. Empiric and definitive therapy considerations are addressed including the potential role of combination therapy. Newer agents with in vitro activity against MDR-PSA (e.g., ceftolozane-tazobactam, ceftazidime-avibactam, imipenem-relebactam, and cefiderocol) and their potential roles in clinical settings are discussed. Although these newer agents are promising options for the treatment of MDR-PSA, clinical data remain generally limited. Future studies are needed to determine optimal agents for the empiric and definitive treatment of MDR-PSA.

Clinical efficacy and pharmacokinetics of colistimethate sodium and colistin in critically ill patients in an Indian hospital with high endemic rates of multidrug-resistant Gram-negative bacterial infections: A prospective observational study

BACKGROUND

Safe and effective use of colistin requires robust pharmacokinetic (PK) and pharmacodynamic (PD) data to guide dosing.

AIM

To evaluate the pharmacokinetics of colistimethate sodium and colistin in critically ill patients and correlate with clinical efficacy and renal function.

MATERIALS AND METHODS

Twenty critically ill adult patients with colistin-susceptible multidrug-resistant (MDR) infections and normal renal function treated with intravenous colistimethate sodium - at a 9 million units (270 mg CBA) loading dose followed by maintenance (MD) of 3 million units t.i.d, 24 hours later - were evaluated for clinical cure (CC) at the end of therapy. Patient characteristics and plasma colistin levels at 0, 0.5, 1, 2, 4, 8 and 12 hours after the loading dose and at 1, 2 and 8 hours after the eighth and ninth infusion of MD were evaluated. Colistimethate sodium and colistin levels were measured by high-performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS).

RESULTS

Among the 20 patients who were evaluated, 60% had pneumonia. Predominant pathogens were Klebsiella pneumoniae and Acinetobacter spp. Clinical cure was 50% (10/20). Mean peak loading dose concentrations were 3 ± 1.1 mg/L (1.75-5.14) and 2.37 ± 1.2 mg/L (1.52-5.54) for 'cure' and 'failure' groups, respectively (p = 0.13), while mean steady-state (Cssavg) concentrations were 2.25 ± 1.3 mg/L and 1.78 ± 1.1 mg/L in 'cure' and 'failure' groups, respectively (p = 0.19). Nephrotoxicity was 5% on day 7 of therapy. However, bacteriological cure could not be correlated with PK/PD.

CONCLUSIONS

Subtherapeutic Cssavg with clinical failure and lower efficacy without significant nephrotoxicity highlights the need for therapeutic drug monitoring to guide colistin dosing.

Risk stratification for multidrug-resistant Gram-negative infections in ICU patients

PURPOSE OF REVIEW

Antimicrobial resistance among Gram-negative microorganisms has alarmingly increased in the past 10 years worldwide. Infections caused by these microorganisms are difficult to treat, especially in critically ill patients.The present review examines how to accurately predict which patients carry a greater risk of colonization or infection on which to base the timely choice of an effective empirical antibiotic treatment regimen and avoid antibiotic overuse.

RECENT FINDINGS

There are many risk factors for acquiring one of many multidrug-resistant Gram-negative microorganisms (MDR-GN); however, scores anticipating colonization, infection among those colonized, or mortality among those infected have a variable accuracy. Accuracy of scores anticipating colonization is low. Scores predicting infections among colonized patients are, in general, better, and ICU patients infected with MDR-GN have a worse prognosis than those infected by non-resistant microorganisms. Scores are, in general, better at excluding patients.

SUMMARY

Despite these limitations, scores continue to gain popularity including those by Giannella, Tumbarello, Johnson, or the scores INCREMENT carbapenem-producing Enterobacteriaceae score, Cano, Tartof, or CarbaSCORE.

Risk Factors of Multidrug-Resistant Bacteria in Lower Respiratory Tract Infections: A Systematic Review and Meta-Analysis

Background

Multidrug-resistant (MDR) bacteria are the main cause of lower respiratory tract infections (LRTIs) with high mortality. The purpose of this study is to identify the risk factors associated with MDR by performing a systematic review and meta-analysis.

Methods

PubMed, EMBASE (via Ovid), and Cochrane Library were systematically searched for studies on the risk factors for MDR bacteria in LRTIs as of November 30, 2019. Literature screening, data abstraction, and quality assessment of the eligible studies were performed independently by two researchers.

Results

A total of 3,607 articles were retrieved, of which 21 articles representing 20 cohort studies published in English were included after title/abstract and full-text screening. Among the 21 articles involving 7,650 patients and 1,360 MDR organisms, ten reported the risk factors for MDR Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB), ten for MDR GNB, and one for MDR GPB. The meta-analysis results suggested that prior antibiotic treatment, inappropriate antibiotic therapy, chronic lung disease, chronic liver disease and cerebral disease, prior MDR and PA infection/colonization, recent hospitalization, longer hospitalization stay, endotracheal tracheostomy and mechanical ventilation, tube feeding, nursing home residence, and higher disease severity score were independent risk factors for MDR bacteria.

Conclusions

This review identified fourteen clinical factors that might increase the risk of MDR bacteria in patients with LRTIs. Clinicians could take into account these factors when selecting antibiotics for patients and determine whether coverage for MDR bacteria is required. More well-designed studies are needed to confirm the various risk factors for MDR bacteria in the future.

Multicenter Evaluation of the BD Phoenix CPO Detect Test for Detection and Classification of Carbapenemase-Producing Organisms in Clinical Isolates

Limited treatment options contribute to high morbidity/mortality rates with carbapenem-resistant, Gram-negative bacterial infections. New approaches for carbapenemase-producing organism (CPO) detection may help inform clinician decision-making on patient treatment and infection control. BD Phoenix CPO detect (CPO detect) detects and classifies carbapenemases in Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa during susceptibility testing.

Limited treatment options contribute to high morbidity/mortality rates with carbapenem-resistant, Gram-negative bacterial infections. New approaches for carbapenemase-producing organism (CPO) detection may help inform clinician decision-making on patient treatment and infection control. BD Phoenix CPO detect (CPO detect) detects and classifies carbapenemases in Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa during susceptibility testing. The clinical performance of CPO detect is reported here. Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa isolates were evaluated across three sites using CPO detect and a composite reference method (RM); the latter was comprised of the modified carbapenem inactivation method and a MIC screen for ertapenem, imipenem, and meropenem. Multiplex PCR testing was also utilized for Ambler class determination. Positive and negative percentages of agreement (PPA and NPA, respectively) between CPO detect and the RM were determined. The PPA and NPA for Enterobacterales were 98.5% (confidence intervals, 96.6%, 99.4%) and 97.2% (95.8%, 98.2%), respectively. The A. baumannii PPA and NPA, respectively, were 97.1% (90.2%, 99.2%) and 97.1% (89.9%, 99.2%). The P. aeruginosa PPA and NPA, respectively, were 95.9% (88.6%, 98.6%) and 92.3% (86.7%, 95.6%). The PPA values for carbapenemase class designations for all organisms combined and Enterobacterales alone, respectively, were 95.3% (90.2%, 97.8%) and 94.6% (88.8%, 97.5%) for class A, 94.0% (88.7%, 96.6%) and 96.4% (90.0%, 98.8%) for class B, and 95.0% (90.1%, 97.6%) and 99.0% (94.4%, 99.8%) for class D carbapenemases. NPA values for all organisms and Enterobacterales alone ranged from 98.5% to 100%. CPO detect provided accurate detection and classification of CPOs for the majority of isolates of Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa tested.

Altering Routine Intensive Care Unit Practices to Support Commensalism

The gastrointestinal (GI) tract consists of trillions of organisms that support multiple functions in the body, from immunity, digestion, and absorption to drug metabolism. These microbes form an overall collection of microorganisms that form the body's microbiome. In critical illness, many of these functions are aberrant, and the microbiome is altered, leading to untoward effects. Some of the most common medications received by patients include antibiotics and proton pump inhibitors, which affect particular changes in the microbiome. In addition, patients receiving prolonged enteral and parenteral nutrition experience changes in the microbiological composition and diversity of their GI tracts. Research is ongoing to characterize the crosstalk between the microbiome and immune function as targets for drug and nutrition therapy.

[A Holiday Souvenir with Consequences - an Interdisciplinary Challenge]

A Holiday Souvenir with Consequences - an Interdisciplinary Challenge Abstract. We describe a patient with a diabetic foot and challenging infectious complications. After a hospital stay in Sri Lanka due to a soft tissue infection of the foot he was relocated to Switzerland. After proof of multiple resistant bacteria, an amputation of the forefoot with a split skin cover was performed, followed by a short resistance-adapted antibiotic treatment, with good clinical results. This case illustrates the increase of multidrug-resistant bacteria, even in Switzerland. It emphasizes the importance of infection control measures in travellers returning from countries with high prevalence of multidrug-resistant bacteria (especially after a hospitalisation), and the need of a close interdisciplinary collaboration in these cases to guarantee the best treatment and to limit the spreading of multidrug-resistant bacteria.

Halophiles and Their Biomolecules: Recent Advances and Future Applications in Biomedicine

The organisms thriving under extreme conditions better than any other organism living on Earth, fascinate by their hostile growing parameters, physiological features, and their production of valuable bioactive metabolites. This is the case of microorganisms (bacteria, archaea, and fungi) that grow optimally at high salinities and are able to produce biomolecules of pharmaceutical interest for therapeutic applications. As along as the microbiota is being approached by massive sequencing, novel insights are revealing the environmental conditions on which the compounds are produced in the microbial community without more stress than sharing the same substratum with their peers, the salt. In this review are reported the molecules described and produced by halophilic microorganisms with a spectrum of action in vitro: antimicrobial and anticancer. The action mechanisms of these molecules, the urgent need to introduce alternative lead compounds and the current aspects on the exploitation and its limitations are discussed.

Pharmacokinetic and pharmacodynamic profiling of four antimicrobials against Acinetobacter baumannii infection

BACKGROUND

The aim of this study was to evaluate common antimicrobial regimens used in eradicating Acinetobacter baumannii in Shenyang, China.

METHODS

Monte Carlo simulation was conducted to estimate the probability target attainment (PTA) and cumulative fraction of response (CFR) for imipenem, cefoperazone/sulbactam (2:1), tigecycline and colistin methanesulfonate.

RESULTS

For the results of PTAs, imipenem following administration of 0.5 g q6 h, 1 g q8 h, and 1 g q6 h for both 0.5 h and 2 h infusion achieved＞90% PTAs when MIC was 8 μg/ml; cefoperazone/ sulbactam (2:1) following administration of 4.5 g q6 h and 6 g q6 h achieved＞90% PTAs when MIC was 64μg/ml; tigecycline following administration of 50 mg q12 h and 100 mg q12 h achieved＞90% PTAs when MIC was 1 μg/ml; colistin methanesulfonate with high dosages (3MU q8 h) could provide high PTA (95.13%) in patients with CL_Cr＜60 ml/min when MIC was 2 μg/ml. As for CFR values of four antibiotics, imipenem achieved the lowest CFR values. For cefoperazone/sulbactam (2:1) and tigecycline, with simulated regimens improvement, the CFR values were both increased, and there were obviously increasing CFR values against Acinetobacter baumannii. For colistin methanesulfonate, the most aggressive dosage of 3MU q8 h could provide satisfactory CFR values (≥86.94%) against Acinetobacter baumannii in patients at various CL_Cr.

CONCLUSION

This study suggested that measurement of MICs, individualized therapy and therapeutic drug-level monitoring should be considered together to achieve the optimal drug exposure. That will provide the best chance of achieving the highest probability of a successful clinical or microbiological response, and avoiding the induced resistance.

Safety, Tolerability, Pharmacokinetics, and Drug Interaction Potential of SPR741, an Intravenous Potentiator, after Single and Multiple Ascending Doses and When Combined with β-Lactam Antibiotics in Healthy Subjects

SPR741 is a novel polymyxin B derivative, with minimal intrinsic antibacterial activity and reduced nonclinical nephrotoxicity compared to levels with polymyxin B, that interacts with the outer membrane of Gram-negative bacteria, enhancing penetration of coadministered antibiotics.

SPR741 is a novel polymyxin B derivative, with minimal intrinsic antibacterial activity and reduced nonclinical nephrotoxicity compared to levels with polymyxin B, that interacts with the outer membrane of Gram-negative bacteria, enhancing penetration of coadministered antibiotics. The safety, tolerability, and pharmacokinetics (PK) of SPR741 were evaluated in two studies, after single and multiple intravenous (i.v.) doses in healthy adult subjects and after coadministration with partner antibiotics. In the single and multiple ascending-dose study, SPR741 or placebo was administered as a 1-h infusion at single doses of 5 to 800 mg and in multiple doses of 50 to 600 mg every 8 h (q8h) for 14 days. In the drug-drug interaction study, a single 400-mg i.v. dose of SPR741 was administered alone and in combination with piperacillin-tazobactam, ceftazidime, and aztreonam. PK parameters for SPR741 and partner antibiotics were determined using noncompartmental analysis. After single doses, a dose-linear and proportional increase in mean maximum concentration in plasma (C_max) and area under the concentration-time curve (AUC) was observed. At doses of 100 to 800 mg, >50% of the dose was excreted in the urine in the first 4 h postdose. After multiple doses, the mean half-life was 2.2 h on day 1 and up to 14.0 h on day 14, with no evidence of accumulation after 14 days of dosing up to 400 mg. The PK profile of SPR741 and partner antibiotics was unchanged with coadministration. SPR741 was generally well tolerated at doses up to 1,800 mg/day. These data support further clinical development of SPR741 for treating serious infections due to resistant bacteria. (These studies have been registered at ClinicalTrials.gov under identifiers NCT03022175 and NCT03376529.)

Faecal microbiota transplantation for eradicating carriage of multidrug-resistant organisms: a systematic review

BACKGROUND

Multidrug-resistant (MDR) microorganism development in the gut is frequently the result of inappropriate antibiotic use. Faecal microbiota transplantation (FMT) restores normal gut microbiota in patients with Clostridium difficile infection. We hypothesized that it may help in decolonizing MDR organisms (MDROs) and in preventing recurrent MDR infections.

OBJECTIVES

To assess FMT efficacy (eradication rate) for decolonizing MDROs and preventing recurrent MDR infections.

DATA SOURCES

Medline, Embase and Web of Science (inception through 11 February 2019).

STUDY ELIGIBILITY CRITERIA

Clinical trials, retrospective studies, case reports and case series.

PARTICIPANTS

Patients with MDR infections or MDRO colonization treated with FMT.

INTERVENTIONS

FMT.

METHODS

Systematic review.

RESULTS

Twenty-one studies (one randomized clinical trial, seven uncontrolled clinical trials, two retrospective cohort studies, two case series, nine case reports) assessing 192 patients were included. Three studies assessed FMT efficacy in preventing MDR infections; 16 assessed its effect on MDRO colonization; two assessed both. Data from 151 patients were included in the final analyses. In studies with low to moderate risk of bias, the eradication rate was 37.5% to 87.5%. Efficacy was similar in studies looking at infection or colonization and did not differ by length of follow-up. No serious adverse events from FMT were reported. Seven patients died of other causes.

CONCLUSIONS

FMT could be used as a treatment for eradicating MDR colonization and possibly preventing recurrent MDR infections, once more supporting efficacy and safety data are available. Larger well-designed randomized controlled trials are needed to further explore this therapy.

Diagnosis of Bacterial Pathogens in the Urine of Urinary-Tract-Infection Patients Using Surface-Enhanced Raman Spectroscopy

(1) Background: surface-enhanced Raman spectroscopy (SERS) is a novel method for bacteria identification. However, reported applications of SERS in clinical diagnosis are limited. In this study, we used cylindrical SERS chips to detect urine pathogens in urinary tract infection (UTI) patients. (2) Methods: Urine samples were retrieved from 108 UTI patients. A 10 mL urine sample was sent to conventional bacterial culture as a reference. Another 10 mL urine sample was loaded on a SERS chip for bacteria identification and antibiotic susceptibility. We concentrated the urine specimen if the intensity of the Raman spectrum required enhancement. The resulting Raman spectrum was analyzed by a recognition software to compare with spectrum-form reference bacteria and was further confirmed by principal component analysis (PCA). (3) Results: There were 97 samples with single bacteria species identified by conventional urine culture and, among them, 93 can be successfully identified by using SERS without sample concentration. There were four samples that needed concentration for bacteria identification. Antibiotic susceptibility can also be found by SERS. There were seven mixed flora infections found by conventional culture, which can only be identified by the PCA method. (4) Conclusions: SERS can be used in the diagnosis of urinary tract infection with the aid of the recognition software and PCA.