Hospital costs of nosocomial multi-drug resistant Pseudomonas aeruginosa acquisition

Impact of multidrug resistance on the virulence and fitness of Pseudomonas aeruginosa: a microbiological and clinical perspective

Pseudomonas aeruginosa is one of the most common nosocomial pathogens and part of the top emergent species associated with antimicrobial resistance that has become one of the greatest threat to public health in the twenty-first century. This bacterium is provided with a wide set of virulence factors that contribute to pathogenesis in acute and chronic infections. This review aims to summarize the impact of multidrug resistance on the virulence and fitness of P. aeruginosa. Although it is generally assumed that acquisition of resistant determinants is associated with a fitness cost, several studies support that resistance mutations may not be associated with a decrease in virulence and/or that certain compensatory mutations may allow multidrug resistance strains to recover their initial fitness. We discuss the interplay between resistance profiles and virulence from a microbiological perspective but also the clinical consequences in outcomes and the economic impact.

Pseudomonas aeruginosa Bacteriophages and Their Clinical Applications

Antimicrobial resistance poses a serious risk to contemporary healthcare since it reduces the number of bacterial illnesses that may be treated with antibiotics, particularly for patients with long-term conditions like cystic fibrosis (CF). People with a genetic predisposition to CF often have recurrent bacterial infections in their lungs due to a buildup of sticky mucus, necessitating long-term antibiotic treatment. Pseudomonas aeruginosa infections are a major cause of CF lung illness, and P. aeruginosa airway isolates are frequently resistant to many antibiotics. Bacteriophages (also known as phages), viruses that infect bacteria, are a viable substitute for antimicrobials to treat P. aeruginosa infections in individuals with CF. Here, we reviewed the utilization of P. aeruginosa bacteriophages both in vivo and in vitro, as well as in the treatment of illnesses and diseases, and the outcomes of the latter.

The contribution of neutrophils to bacteriophage clearance and pharmacokinetics in vivo

With the increasing prevalence of antimicrobial-resistant bacterial infections, there is great interest in using lytic bacteriophages (phages) to treat such infections. However, the factors that govern bacteriophage pharmacokinetics in vivo remain poorly understood. Here, we have examined the contribution of neutrophils, the most abundant phagocytes in the body, to the pharmacokinetics of intravenously administered bacteriophage in uninfected mice. A single dose of LPS-5, an antipseudomonal bacteriophage recently used in human clinical trials, was administered intravenously to both wild-type BALB/c and neutropenic ICR mice. Phage concentrations were assessed in peripheral blood and spleen at 0.5, 1, 2, 4, 8, 12, and 24 hours after administration by plaque assay and qPCR. We observed that the phage clearance is only minimally affected by neutropenia. Indeed, the half-life of phages in blood in BALB/c and ICR mice is 3.45 and 3.66 hours, respectively. These data suggest that neutrophil-mediated phagocytosis is not a major determinant of phage clearance. Conversely, we observed a substantial discrepancy in circulating phage levels over time when measured by qPCR versus plaque assay, suggesting that substantial functional inactivation of circulating phages occurs over time. These data indicate that circulating factors, but not neutrophils, inactivate intravenously administered phages.

The Inactivation of the Putative Two-Component System Sensor PA14_27940 Increases the Susceptibility to Several Antibiotics and Reduces the Motility of Pseudomonas aeruginosa

The identification of targets whose inactivation increases the activity of antibiotics helps to fight antibiotic resistance. Previous work showed that a transposon-insertion mutant in the gene PA14_27940 increases Pseudomonas aeruginosa susceptibility to aminoglycosides. Since polar effects may affect the phenotype, in the present work, we generated an in-frame PA14_27940 deletion mutant. A PA14_27940 deletion increased the susceptibility to aminoglycosides, tetracycline, tigecycline, erythromycin and fosfomycin. Excepting fosfomycin, the other antibiotics are inducers of the MexXY efflux pump. MexXY induction is required for P. aeruginosa resistance to these antibiotics, which is post-transcriptionally regulated by the anti-repressor ArmZ. Although mexXY is inducible by tobramycin in ΔPA14_27940, the induction level is lower than in the parental PA14 strain. Additionally, armZ is induced by tobramycin in PA14 and not in ΔPA14_27940, supporting that ΔPA14_27940 presents an ArmZ-mediated defect in mexXY induction. For its part, hypersusceptibility to fosfomycin may be due to a reduced expression of nagZ and agmK, which encode enzymes of the peptidoglycan recycling pathway. ΔPA14_27940 also presents defects in motility, an element with relevance in P. aeruginosa's virulence. Overall, our results support that PA14_27940 is a good target for the search of adjuvants that will increase the activity of antibiotics and reduce the virulence of P. aeruginosa.

Therapeutic effect and anti-biofilm ability assessment of a novel phage, phiPA1-3, against carbapenem-resistant Pseudomonas aeruginosa

Multiple drug-resistant (MDR) Pseudomonas aeruginosa commonly causes severe hospital-acquired infections. The gradual emergence of carbapenem-resistant P. aeruginosa has recently gained attention. A wide array of P. aeruginosa-mediated pathogenic mechanisms, including its biofilm-forming ability, limits the use of effective antimicrobial treatments against it. In the present study, we isolated and characterized the phenotypic, biological, and genomic characteristics of a bacteriophage, vB_PaP_phiPA1-3 (phiPA1-3). Biofilm eradication and phage rescue from bacterial infections were assessed to demonstrate the efficacy of the application potential. Host range spectrum analysis revealed that phiPA1-3 is a moderate host range phage that infects 20% of the clinically isolated strains of P. aeruginosa tested, including carbapenem-resistant P. aeruginosa (CRPA). The phage exhibited stability at pH 7.0 and 9.0, with significantly reduced viability below pH 5.0 and beyond pH 9.0. phiPA1-3 is a lytic phage with a burst size of 619 plaque-forming units/infected cell at 37 °C and can effectively lyse bacteria in a multiplicity of infection-dependent manner. The genome size of phiPA1-3 was found to be 73,402 bp, with a G+C content of 54.7%, containing 93 open reading frames, of which 62 were annotated as hypothetical proteins and the remaining 31 had known functions. The phage possesses several proteins similar to those found in N4-like phages, including three types of RNA polymerases. This study concluded that phiPA1-3 belongs to the N4-like Schitoviridae family, can potentially eradicate P. aeruginosa biofilms, and thus, serve as a valuable tool for controlling CRPA infections.

Phenotypic and genomic characterization of Pseudomonas aeruginosa isolates recovered from catheter-associated urinary tract infections in an Egyptian hospital

Catheter-associated urinary tract infections (CAUTIs) represent one of the major healthcare-associated infections, and Pseudomonas aeruginosa is a common Gram-negative bacterium associated with catheter infections in Egyptian clinical settings. The present study describes the phenotypic and genotypic characteristics of 31 P. aeruginosa isolates recovered from CAUTIs in an Egyptian hospital over a 3 month period. Genomes of isolates were of good quality and were confirmed to be P. aeruginosa by comparison to the type strain (average nucleotide identity, phylogenetic analysis). Clonal diversity among the isolates was determined; eight different sequence types were found (STs 244, 357, 381, 621, 773, 1430, 1667 and 3765), of which ST357 and ST773 are considered to be high-risk clones. Antimicrobial resistance (AMR) testing according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines showed that the isolates were highly resistant to quinolones [ciprofloxacin (12/31, 38.7 %) and levofloxacin (9/31, 29 %) followed by tobramycin (10/31, 32.5 %)] and cephalosporins (7/31, 22.5 %). Genotypic analysis of resistance determinants predicted all isolates to encode a range of AMR genes, including those conferring resistance to aminoglycosides, β-lactamases, fluoroquinolones, fosfomycin, sulfonamides, tetracyclines and chloramphenicol. One isolate was found to carry a 422 938 bp pBT2436-like megaplasmid encoding OXA-520, the first report from Egypt of this emerging family of clinically important mobile genetic elements. All isolates were able to form biofilms and were predicted to encode virulence genes associated with adherence, antimicrobial activity, anti-phagocytosis, phospholipase enzymes, iron uptake, proteases, secretion systems and toxins. The present study shows how phenotypic analysis alongside genomic analysis may help us understand the AMR and virulence profiles of P. aeruginosa contributing to CAUTIs in Egypt.

Tazobactam/ceftolozane and tobramycin combination therapy in extensively drug-resistant Pseudomonas aeruginosa infections in severe burn injury: a case report

BACKGROUND

Combination therapy with tazobactam/ceftolozane (TAZ/CTLZ) and high-dose aminoglycosides has been reported to be efficacious in extensively drug-resistant (XDR)-Pseudomonas aeruginosa infection. However, there are no reports of efficacy in XDR-P. aeruginosa infection for combination therapy with low-dose aminoglycosides and TAZ/CTLZ. Herein, we describe a rare case of severe burn injury patients with persistent bacteremia due to XDR-P. aeruginosa, which was successfully treated with TAZ/CTLZ and low-dose tobramycin (TOB).

CASE PRESENTATION

A 31-year-old man was admitted to the intensive care unit with severe burn injury involving 52% of the total body surface area and a prognostic burn index of 79.5. The patient had recurrent bacterial infections since admission, and blood cultures collected on the 37th day of admission revealed the presence of P. aeruginosa strains that were resistant to all β-lactams and amikacin (AMK). The results of the antimicrobial synergistic study showed no synergistic effect of low-dose meropenem (MEPM) and AMK combination therapy. The patient had acute renal failure, and it was difficult to increase the dose of MEPM and AMK, respectively. Thus, we initiated TAZ/CTLZ 1.5 g/8 h instead of the AMK and MEPM combination therapy on the 43rd day of hospitalization. Low-dose TAZ/CTLZ was continued because of prolonged renal dysfunction and resulted in a transient clinical improvement. However, the dosage of TAZ/CTLZ could be increased as the renal function improved, but despite an increased TAZ/CTLZ dose, bacteremia persisted, and the blood cultures remained positive. Thus, TOB was added to TAZ/CTLZ at low doses for synergistic effect against Gram-negative bacteria. Blood cultures collected after initiation of combination therapy with TAZ/CTLZ and low-dose TOB were negative on two consecutive follow-up evaluations. Thereafter, although the patient had several episodes of fever and increased inflammatory response, blood cultures consistently tested negative, and all of the wounds healed. On the 93rd day, due to the good healing progress, the patient was transferred to another hospital.

CONCLUSIONS

TAZ/CTLZ and low-dose TOB combination therapy showed the potential for synergistic effects. Our present report suggests a novel synergistic treatment strategy for rare cases that are refractory to the treatment of infections, such as XDR-P. aeruginosa infection.

Emergence of Extended-Spectrum Beta-Lactamase and Carbapenemase Producing Gram Negative Non-Fermenters at Selected Hospitals of Northeast Ethiopia: A Prospective Cross-Sectional Study

Background

The emergence and spread of extended-spectrum β-lactamases (ESβLs) and carbapenemase (CP) producing gram negative non-fermenters are becoming a serious public health threat globally. Infections caused by these pathogens limit treatment options and contribute to the significant morbidity and mortality. Thus, to reduce their spread, early detection of these superbugs is very crucial. This study therefore aimed to assess the prevalence of ESβLs and CP producing gram negative non-fermenters at selected hospitals of North East Ethiopia.

Methods

A cross-sectional study was conducted from January to June 2021. Acinetobacter baumannii (A. baumannii) and Pseudomonas aeruginosa (P. aeruginosa) were identified using standard bacteriological techniques. ESβL and CP production were detected by combined disk diffusion and modified carbapenem inhibitory methods, respectively. Data were collected via face-to-face interview and patient card review. Chi-squared and Fisher's exact tests were calculated and p-value < 0.05 was considered statistically significant.

Results

A total of 384 patients participated in this study. Overall, 30 (7.8%) patients had positive culture for A. baumannii and P. aeruginosa. The prevalence of A. baumannii was 20 (5.2%) and that of P. aeruginosa was 10 (2.6%). From the overall isolates, 16 (53.3%) were ESβL and the proportion of carbapenemase production was 4 (13.3%). ESβL production was 8 (40%) in A. baumannii and 8 (80%) in P. aeruginosa isolates. ESβL production infections were significantly associated with hospitalization (p=0.004). Intravenous catheterization, hospitalization, and surgery had significant association with ESβL production (p<0.005). All isolates of A. baumannii and P. aeruginosa were MDR.

Conclusion

ESβL and carbapenemase production among A. baumannii and P. aeruginosa were high in the selected hospitals. The treatment of such resistant infectious agents should be guided by antimicrobial susceptibility test in a study setting. Thus, restricted and wise use of antibiotics is highly recommended to contain the spread of these superbugs. Hospitals should develop infection prevention guidelines to prevent the spread of resistant pathogens in hospitalized patients.

Multi-Model Strategies for Prevention of Infection Caused by Certain Multi-Drug Resistant Organisms in A Rehabilitation Unit: A Semi-Experimental Study

Objective: To assess the effectiveness of multi-model strategies on healthcare-associated infections (HAIs) caused by multi-drug resistant organisms (MDROs) in rehabilitation units. Methods: A semi-experimental study was conducted in a rehabilitation unit with 181 beds from January 2021 to December 2022 in a teaching hospital with 4300 beds in China. In 2021, many basic prevention and control measures were conducted routinely. Based on the basic measures, strengthening multi-model strategies for the prevention and control of MDROs was pursued year-round since 1 January 2022. Results: A total of 6206 patients were enrolled during the study period. The incidence density of HAIs caused by MDROs decreased from 1.22 (95% CI, 0.96~1.54) cases/1000 patient-days in the pre-intervention period to 0.70 (95% CI, 0.50~0.95) cases/1000 patient-days (p = 0.004). Similarly, the incidence of HAIs in the intervention period was 50.85% lower than that in the pre-intervention period (2.02 (95% CI, 1.50~2.72) vs. 4.11 (95% CI, 3.45-4.85) cases/100 patients, p < 0.001). The rate of MDROs isolated from the environment decreased by 30.00%, although the difference was not statistically significant (p = 0.259). Conclusion: Multi-model strategies can reduce the incidence of HAIs and HAIs caused by certain MDROs in the rehabilitation unit.

The impact of multi-drug resistant Pseudomonas aeruginosa infections on acute pancreatitis patients

INTRODUCTION

Acute pancreatitis (AP) accounts for a high proportion of digestive diseases worldwide and has a high risk of infection. Pseudomonas aeruginosa, a common pathogen of hospital infections, has been observed to increase the resistance rate to several antibiotics, causing difficulties in treatments. Our study aims to investigate the impact of the multi-drug resistant Pseudomonas aeruginosa (MDR-PA) infections on AP patients.

METHODS

At two Chinese tertiary referral centers for AP patients infected with MDR-PA, a retrospective case-control study with a 1:2 case-control ratio was performed. Comparisons were preformed between with/without MDR-PA infections and different drug-resistance of MDR-PA infections patients, respectively. Independent risk factors of overall mortality were assessed via univariate and multivariate binary logistic regression analyses, and the distribution and antibiotic resistant rates of strains were described.

RESULTS

Mortality in AP patients with MDR-PA infections was significantly higher than in those without MDR-PA infections (7 (30.4%) vs. 4 (8.7%), P = 0.048). The rate of prophylactic use of carbapenem for 3 days (0 vs. 50%, P = 0.019) and the incidence rate of multiple organ failure (MOF) (0 vs. 57.1%, P = 0.018) were remarkably higher in the carbapenem-resistant Pseudomonas aeruginosa group compared with the carbapenem-sensitive Pseudomonas aeruginosa group. In the multivariate analysis, the severe categories of AP (OR = 13.624, 95% CIs = 1.567-118.491, P = 0.018) and MDR-PA infections (OR = 4.788, 95% CIs = 1.107-20.709, P = 0.036) were independent risk factors for mortality. The resistance rates of MDR-PA strains were low for amikacin (7.4%), tobramycin (3.7%), and gentamicin (18.5%). The resistance rates of MDR-PA strains to imipenem and meropenem were up to, 51.9% and 55.6%, respectively.

CONCLUSION

In AP patients, severe categories of AP and MDR-PA infections were both independent risk factors for mortality. Inappropriate use of carbapenem antibiotics and MOF were related to carbapenem-resistant Pseudomonas aeruginosa infections. Amikacin, tobramycin, and gentamicin are recommended for the treatment of AP patients with MDR-PA infections.

Epidemiological, Microbiological, and Clinical Characteristics of Multi-Resistant Pseudomonas aeruginosa Isolates in King Fahad Medical City, Riyadh, Saudi Arabia

Increasing rates of serious multi-drug resistant (MDR) Pseudomonas aeruginosa infections have been reported globally, including in Saudi Arabia. This retrospective study investigates the epidemiological, microbiological, and clinical characteristics of multi-resistant P. aeruginosa (n3579 clinical isolates) in King Fahad Medical City, Riyadh, Saudi Arabia (2019–2021). Information on antimicrobial susceptibility and medical history was collected from the hospital database. P. aeruginosa infections occurred in 55.6% of males and 44.4% of females, and P. aeruginosa was more prevalent in children than in adults. Our analysis showed that P. aeruginosa had the highest sensitivity to amikacin (92.6%) and greatest resistance to aztreonam (29.8%), imipenem (29.5%), ceftazidime (26.1%), meropenem (25.6%), and cefepime (24.3%). MDR and extensively drug resistant (XDR) strains were more prevalent in male than female patients. Female patients showed higher rates of infection with pan-drug resistant (PDR) strains. Respiratory samples contained the majority of resistant isolates. Septic shock and liver disease were strongly correlated with mortality in the ICU patient group after analysing the relative risk associated with mortality. Our study emphasises the threat of multi-resistant P. aeruginosa in Saudi Arabia (and potentially the Middle East) and highlights important sources and contexts of infection that inhibit its effective control and clinical management.

Trends in Pseudomonas aeruginosa (P. aeruginosa) Bacteremia during the COVID-19 Pandemic: A Systematic Review

Pseudomonas aeruginosa (P. aeruginosa) is among the most common pathogens associated with healthcare-acquired infections, and is often antibiotic resistant, causing significant morbidity and mortality in cases of P. aeruginosa bacteremia. It remains unclear how the incidence of P. aeruginosa bacteremia changed during the Coronavirus Disease 2019 (COVID-19) pandemic, with studies showing almost contradictory conclusions despite enhanced infection control practices during the pandemic. This systematic review sought to examine published reports with incidence rates for P. aeruginosa bacteremia during (defined as from March 2020 onwards) and prior to the COVID-19 pandemic. A systematic literature search was conducted in accordance with PRISMA guidelines and performed in Cochrane, Embase, and Medline with combinations of the key words (pseudomonas aeruginosa OR PAE) AND (incidence OR surveillance), from database inception until 1 December 2022. Based on the pre-defined inclusion criteria, a total of eight studies were eligible for review. Prior to the pandemic, the prevalence of P. aeruginosa was on an uptrend. Several international reports found a slight increase in the incidence of P. aeruginosa bacteremia during the COVID-19 pandemic. These findings collectively highlight the continued importance of good infection prevention and control and antimicrobial stewardship during both pandemic and non-pandemic periods. It is important to implement effective infection prevention and control measures, including ensuring hand hygiene, stepping up environmental cleaning and disinfection efforts, and developing timely guidelines on the appropriate prescription of antibiotics.

Clinical Impact and Risk Factors of Intensive Care Unit-Acquired Nosocomial Infection: A Propensity Score-Matching Study from 2018 to 2020 in a Teaching Hospital in China

Purpose

Nosocomial infection (NI) is associated with poor prognosis. The present study assessed the clinical and microbiological characteristics of NI patients in the intensive care unit (ICU) and investigated the clinical impact and risk factors for NI in ICU patients.

Patients and Methods

An observational study was conducted in an adult general ICU. The electronic medical records of all patients admitted to the ICU for >2 days from 2018-2020 were analyzed retrospectively. Multivariate regression models were used to analyze the risk factors for NI in ICU patients. Propensity score-matching (PSM) was used to control the confounding factors between the case and control groups, thus analyzing the clinical impact of NIs.

Results

The present study included 2425 patient admissions, of which 231 (9.53%) had NI. Acinetobacter baumannii (33.0%) was the most common bacteria. Long-term immunosuppressive therapy, disturbance of consciousness, blood transfusion, multiple organ dysfunction syndromes (MODS), treatment with three or more antibiotics, mechanical ventilation (MV), tracheotomy, the urinary catheter (UC), nasogastric catheter, and central venous catheter (CVC) were risk factors for NI in the ICU patients. After PSM, patients with NI had a prolonged length of stay (LOS) in the ICU and hospital, significant hospitalization expenses (all p<0.001), increased mortality (p=0.027), and predicted mortality (p=0.007). The differences in the ICU and hospital LOSs among three pathogens were statistically significant (p<0.001); the results of the Escherichia coli infection group were lower than the other two pathogenic groups.

Conclusion

NI was associated with poor outcomes. The risk factors for NI identified in this study provided further insight into preventing NI.

Emergence of High Antimicrobial Resistance among Critically Ill Patients with Hospital-Acquired Infections in a Tertiary Care Hospital

Background and Objectives: Inappropriate antibiotic usage in hospitalized patients contributes to microbial resistance. Our study aimed to examine the incidence of clinical bacterial isolates and their antibiotic resistance burden among critically ill patients in different hospital units. Materials and Methods: A single-centered cross-sectional study was conducted in a 120-bed tertiary care hospital that included 221 critically ill patients with hospital-acquired infections. Bacterial cultures and sensitivity reports were obtained and followed by a formal analysis of the antibiogram results to explore recovered isolates' prevalence and antibiotic susceptibility patterns. Results: Gram-negative bacteria were the most predominant pathogens among recovered isolates from the various hospital units (71%). Klebsiella sp. was the most prevalent microbe, followed by Acinetobacter sp., with an incidence level of 28% and 16.2%, respectively. Among the Gram-positive organisms, the coagulase-negative Staphylococci were the most predominant organism (11.3%), while (6.3%) methicillin-resistant Staphylococcus aureus (MRSA) isolates were recovered from different hospital units. Antibiotic sensitivity testing showed that polymyxin B was the most effective antibiotic against Gram-negative bacteria, whereas vancomycin and linezolid were the most active antibiotics against Gram-positive pathogens. Moreover, 7% of the Gram-negative bacteria isolated from different units showed positive production of extended-spectrum beta-lactamase (ESBL). Conclusions: The current study describes the high antibiotic resistance patterns in various hospital units that need extra legislation to prevent healthcare providers from misprescription and overuse of antibiotics.

Comparative Analysis of Complicated Urinary Tract Infections Caused by Extensively Drug-Resistant Pseudomonas aeruginosa and Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae

The objective was to compare clinical characteristics, outcomes, and economic differences in complicated urinary tract infections (cUTI) caused by extensively drug-resistant Pseudomonas aeruginosa (XDR P. aeruginosa) and extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-K. pneumoniae). A retrospective study was conducted at a tertiary care hospital. Patients with XDR P. aeruginosa and ESBL-K. pneumoniae cUTIs were compared. The primary outcome was clinical failure at day 7 and at the end of treatment (EOT). Secondary outcomes: 30- and 90-day mortality, microbiological eradication, and economic cost. Two-hundred and one episodes were included, of which 24.8% were bloodstream infections. Patients with XDR P. aeruginosa cUTI more frequently received inappropriate empirical therapy (p < 0.001). Nephrotoxicity due to antibiotics was only observed in the XDR P. aeruginosa group (26.7%). ESBL-K. pneumoniae cUTI was associated with worse eradication rates, higher recurrence, and higher infection-related readmission. In multivariate analysis, XDR P. aeruginosa was independently associated with clinical failure on day 7 of treatment (OR 4.34, 95% CI 1.71−11.04) but not at EOT, or with mortality. Regarding hospital resource consumption, no significant differences were observed between groups. XDR P. aeruginosa cUTI was associated with worse early clinical cures and more antibiotic side effects than ESBL-K. pneumoniae infections. However, no differences in mortality or in hospitalization costs were observed.

Isolation and characterisation of carbapenem-resistant Pseudomonas aeruginosa from hospital environments in tertiary care hospitals in Dhaka, Bangladesh

OBJECTIVES

Increasing evidence of carbapenem-resistant Pseudomonas aeruginosa (CRPA) infection in healthcare facilities poses an alarming threat to public health. There is little evidence on the occurrence of this organism in Bangladeshi hospitals.

METHODS

We collected 117 environmental swab samples from two tertiary care hospitals in Dhaka, Bangladesh and tested for Pseudomonas species by nonselective enrichment of swabs followed by plating on Cetrimide agar. We confirmed the isolates as P. aeruginosa by API 20NE test and polymerase chain reaction Polymerase Chain Reaction (PCR) for 16S rRNA gene. We analysed P. aeruginosa isolates for susceptibility against 15 clinically important antibiotics and tested the carbapenem-resistant isolates for metallo β-lactamase (MBL). All CRPA isolates were characterised for carbapenem-resistant genes, virulence genes and biofilm formation genes.

RESULTS

Of 117 swab samples, 82 (70%) were tested positive for P. aeruginosa. All P. aeruginosa isolates were multidrug-resistant, and 39% (n = 32) of isolates were CRPA. Around 56% (n = 18) of CRPA were MBL-producing; 22% (n = 7) of isolates were positive for carbapenemase gene bla_NDM followed by 16% (n = 5) for bla_VIM and 13% (n = 4) for bla_IMP. Sequencing identified these genes as bla_NDM-1, bla_IMP-13, bla_VIM-2 variants. Based on optical density values, 94% (n = 30) of CRPA isolates were capable of producing biofilms. All CRPA isolates (n = 32) were positive for at least 1 of 6 biofilm-associated genes and 4 of 12 virulence genes tested in the study.

CONCLUSION

Hospital environments in Bangladesh are contaminated with highly virulent CRPA, which might be a potential source of hospital-acquired infections, accentuating the need for strengthening hospital infection control programs.

Perception of Professionals from Different Healthcare Units Regarding the Use of Spray Technology for the Instantaneous Decontamination of Personal Protective Equipment during the Coronavirus Disease Pandemic: A Short Analysis

Within the context of the coronavirus disease (COVID-19) pandemic, different disinfection technologies have been developed to efficiently exercise microbial control, especially to minimize the potential risks that are associated with transmission and infection among healthcare professionals. Thus, the aim of this work was to evaluate the perception of professionals regarding the use of a new technology (chamber) for the instantaneous decontamination of personal protective equipment before the doffing stage. This was a cross-sectional descriptive study where the study data were obtained by using a questionnaire with qualitative questions. In total, 245 professionals participated in the study in three hospitals. Healthcare professionals represented 72.24% (n = 177) of the investigated sample. Approximately 69% of the professionals considered the disinfection chamber as a safe technology, and 75.10% considered it as an important and effective protective barrier for healthcare professionals in view of its application before the doffing process. The results found in this study demonstrate that the use of spray technology in the stage prior to the doffing process is acceptable to professionals, and that it can be an important tool for ensuring the additional protection of the professionals who work directly with patients who are diagnosed with COVID-19.

pH Responsive Antibacterial Hydrogel Utilizing Catechol-Boronate Complexation Chemistry

Bacteria such as Methicillin-resistant Staphylococcus aureus (MRSA) causes acidic microenvironment during infection. A biomaterial that exhibits tunable antimicrobial property in a pH dependent manner is potentially attractive. Herein, we presented a novel antibacterial hydrogel consisting of pH responsive and reversible catechol-boronate linkage formed between intrinsically bactericidal chlorinated catechol (catechol-Cl) and phenylboronic acid. Fourier transformed infrared spectroscopy (FTIR), oscillatory rheometry, and Johnson Kendall Roberts (JKR) contact mechanics testing confirmed the formation and dissociation of the complex in a pH dependent manner. When the hydrogel was treated with an acidic buffer (pH 3), the hydrogel exhibited excellent antimicrobial property against multiple strains of Gram-positive and negative bacteria including MRSA (up to 4 log₁₀ reduction from 10⁸ colony forming units/mL). At an acidic pH, catechol-Cl was unbound from the phenylboronic acid and available for killing bacteria. Conversely, when the hydrogel was treated with a basic buffer (pH 8.5), the hydrogel lost its antimicrobial property but also became non-cytotoxic. At a basic pH, the formation of catechol-boronate complex effectively reduce the exposure of the cytotoxic catechol-Cl to the surrounding. When further incubating the hydrogel in an acidic pH, the reversible complex dissociated to re-expose catechol-Cl and the hydrogel recovered its antibacterial property. Overall, the combination of catechol-Cl and phenylboronic acid provide a new strategy for designing hydrogels with pH responsive antibacterial activity and reduced cytotoxicity.

The Resistance Patterns in E. coli Isolates among Apparently Healthy Adults and Local Drivers of Antimicrobial Resistance: A Mixed-Methods Study in a Suburban Area of Nepal

Evidence-based decision-making to combat antimicrobial resistance (AMR) mandates a well-built community-based surveillance system for assessing resistance patterns among commensals and pathogenic organisms. As there is no such surveillance system in Nepal, we attempted to describe the antimicrobial resistance pattern in E. coli isolated from the fecal samples of apparently healthy individuals in Dhulikhel municipality and also explored the local drivers of AMR. We used a mixed-method design with a cross-sectional quantitative component and a descriptive qualitative component, with focus group discussion and key informant interviews as the data collection method. Fecal samples were collected from 424 individuals randomly selected for the study. E. coli was isolated from 85.9% of human fecal samples, of which 14% were resistant to ≥3 class of antimicrobials (multidrug resistant). Of the 368 isolates, resistance to ampicillin (40.0%), tetracycline (20.7%) and cefotaxime (15.5%) were most prevalent. The major drivers of AMR were: lack of awareness of AMR, weak regulations on sales of antimicrobials, poor adherence to prescribed medications, and incomplete dosage due to financial constraints. These findings indicate the need for strict implementation of a national drug act to limit the over-the-counter sales of antimicrobials. Additionally, awareness campaigns with a multimedia mix are essential for educating people on AMR.

Economic and clinical burden from carbapenem-resistant bacterial infections and factors contributing: a retrospective study using electronic medical records in Japan

Background

Antimicrobial resistance is a major threat to global health and the world economy. The economic burden of carbapenem-resistant infections has not previously been evaluated. We aimed to compare the potential economic burden and clinical outcomes between carbapenem-resistant infections and carbapenem-susceptible infections in Japan.

Methods

We conducted a retrospective cohort study using electronic medical records. Patients aged 15 years or older and with the diagnosis of pneumonia, urinary tract infection, biliary infection, and sepsis were included. Multivariable regression models with random effects were used to estimate the impact of carbapenem resistance on cost, length of hospital stay, and in-hospital mortality.

Results

Among the 9,517 patients, 86 (0.9%) had carbapenem-resistant (CR) infections. Compared to carbapenem-susceptible (CS) infections, the patients with the CR infections were significantly more likely to receive mechanical ventilation (37.2 vs. 21.2%, P-value = 0.003), antibiotics (88.4 vs. 63.0%, P-value < 0.001), and especially carbapenem (31.4 vs. 8.3%, P-value < 0.001), before the bacterial culture test positive. Significantly higher median costs were found for the CR infections than the CS infections in the categories of medications (3477 US dollars vs. 1609 US dollars), laboratory tests (2498 US dollars, vs. 1845 US dollars), and hospital stay (14,307 US dollars vs. 10,560 US dollars). In the multivariable regression analysis, the length of stay was 42.1% longer and the cost was 50.4% higher in the CR infections than in the CS infections. The risk of in-hospital mortality did not differ between the two groups (odds ratio 1.24, 95% CI 0.72–2.11), due to the small sample size. The result was robust with a similar trend in the analysis using the inverse probability treatment weighting method.

Conclusions

Compared to carbapenem-susceptible infections, carbapenem-resistant infections were associated with a higher cost and a longer length of stay. Detailed cost analysis showed significant differences in the categories of medication, laboratory tests, and hospital stay. To our knowledge, this study is the first to assess the potential economic burden of carbapenem-resistant infections using a large hospital-based database.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07548-3.

Phenotypic and genotypic within-host diversity of Pseudomonas aeruginosa urinary isolates

This study aimed to assess phenotypic and molecular inter-patient and within-host diversity of Pseudomonas aeruginosa isolates responsible for urinary tract infection (UTI) or asymptomatic bacteriuria (AB). Clinical data of 120 consecutive P. aeruginosa UTI (n = 40) and AB (n = 80) were prospectively analyzed. Up to five P. aeruginosa isolates per sample were collected. Antimicrobial susceptibility testing (AST) was determined for all isolates (n = 591); a subset of 358 was characterized by multilocus sequence typing. 444 isolates (75%) were non-multidrug resistant (MDR), 113 (19%) were MDR, and 34 (6%) were extensively drug resistant. A genetically highly diverse population was observed (64 sequence types [STs]), without strict correlation between genotypes and clinical settings. 35 patients (28%; 12 UTIs and 23 ABs) presented distinct antimicrobial resistance (AMR) profiles within a given urine sample, significantly associated with previous carbapenem and fluroquinolones exposure; five of them also exhibited polyclonal UTI or AB (with isolates belonging to two STs). P. aeruginosa urinary isolates of these 120 patients were highly diverse, in terms of AMR as well as genetic background. Both within-host AMR and molecular diversity can complicate AST, treatment and control of P. aeruginosa UTI.

Derivation of a score to predict infection due to multi-drug resistant Pseudomonas aeruginosa: A tool for guiding empirical antibiotic treatment

BACKGROUND

Multidrug-resistant Pseudomonas aeruginosa (MDR-PSA) constitutes an emerging health problem. A predictive score of MDR-PSA infection would let early adaptation of empirical antibiotic therapy.

METHODS

We performed a single-center case-control (1:2) retrospective study including 100 patients with MDR-PSA and 200 with non-MDR-PSA infection. Cases and controls were matched by site of infection, clinical characteristics and immunosuppression. A point risk score for prediction of MDR-PSA infection was derived from a logistic regression model. Secondary outcomes (clinical improvement, complications and discharge) were also compared.

RESULTS

Cases with MDR-PSA infection were younger than controls (67.5 vs. 73.0 years; P=0.031) and have more frequently cirrhosis (9% vs. 2%; P=0.005). Independent risk factors for MDR-PSA infection were prior antibiotic treatment (80% vs. 50.5%; P<0.001), prior colonization with MDR bacteria (41% vs. 13.5%; P<0.001), hospital-acquired infection (63% vs. 47%; P=0.009), and septic shock at diagnosis (33% vs. 14%; P<0.001). Adequate therapy was less frequent in MDR-PSA infections (31% vs. 66.5% for empirical therapy; P<0.001). The risk score included: previous MDR-PSA isolation (11 points), prior antibiotic use (3 points), hospital-acquired infection (2 points), and septic shock at diagnosis (2 points). It showed an area under the curve of 0.755 (95% CI: 0.70-0.81) and allowed to classify individual risk into various categories: 0-2 points (<20%), 3-5 points (25-45%), 7-11 points (55-60%), 13-16 points (75-87%) and a maximum of 18 points (93%).

CONCLUSIONS

Infections due to MDR-PSA have a poorer prognosis than those produced by non-MDR-PSA. Our score could guide empirical therapy for MDR-PSA when P. aeruginosa is isolated.

Imipenem Resistance in Gram-Negative Bacteria in the Central Pediatric Teaching Hospital in Baghdad, Iraq

Antimicrobial resistance (AMR) is a serious challenge for infectious disease prevention and treatment, according to the World Health Organization. It is a worldwide problem caused primarily by inappropriate and insufficient therapy, misuse of antimicrobials without physician supervision, unnecessary hospital readmissions, and other factors. AMR has several consequences, including increased medical costs and mortality. The present study aimed to evaluate imipenem resistance in gram-negative bacteria in Central Pediatric Teaching Hospital in Baghdad, Iraq, and determine this bacteria resistance in different samples. Initially, a total of 100 different samples were collected from child patients from October 1, 2020, to August 31, 2021. Each isolate was identified using VITEK 2 automated microbiology system. The recorded data showed that the isolated organisms resistant to imipenem included Klebsiella pneumonia (n=21), Pseudomonas aeruginosa (n=19), and Acinetobacter baumannii (n=16). In the current study, Klebsiella pneumonia was the most common pathogen in males (n=57) compared to female (n=43), followed by Pseudomonas aeruginosa and Acinetobacter baumannii, particularly in the age range of 1 day- 3 years. Depending on the sample type, Klebsiella pneumonia, the most imipenem-resistant bacteria, was found more in the urine of patients with urinary tract infections. Pseudomonas aeruginosa was equally found in blood, urine, wound swab, and sputum samples. In comparison to other samples, Acinetobacter baumannii was found in greater numbers in the blood and in an equal number in urine and cerebrospinal.

Beta-Lactam vs. Fluoroquinolone Monotherapy for Pseudomonas aeruginosa Infection: A Systematic Review and Meta-Analysis

Introduction: Pseudomonas aeruginosa (PA) is a leading cause of healthcare-associated infections. A variety of antibiotic classes are used in the treatment of PA infections, including beta-lactams (BLs) and fluoroquinolones (FQs), given either together in combination therapy or alone in monotherapy. A systematic review and meta-analysis were performed to evaluate the therapeutic efficacy of BL agents versus FQ agents as active, definitive monotherapy in PA infections in adults. Methods: Comprehensive literature searches of the Medline and Scopus electronic databases, alongside hand searches of the Cochrane Database of Systematic Reviews, PubMed, and Google Scholar, were performed without a time restriction to identify studies published in English comparing BL and FQ agents given as monotherapy for PA infection in hospitalized adults for which mortality, bacteriological eradication, or clinical response was evaluated. One reviewer screened search results based on pre-defined selection criteria. Two reviewers independently assessed included studies for methodological quality using NIH assessment tools. Two fixed-effects meta-analyses were performed. Results: A total of 368 articles were screened, and six studies involving 338 total patients were included in the meta-analysis. Upon evaluation of methodological quality, two studies were rated good, three fair, and one poor. A meta-analysis of three studies demonstrates FQ monotherapy is associated with significantly improved survival compared to BL monotherapy for patients with PA bacteremia (OR, 3.65; 95% CI, 1.27–10.44; p = 0.02). A meta-analysis of three studies demonstrates FQ monotherapy is associated with equivalent bacteriological eradication compared to BL monotherapy for PA pneumonia or skin and soft tissue infection (RD, 0.07; 95% CI, −0.09 to 0.24; p = 0.39). Conclusion: The meta-analyses demonstrate FQ monotherapy significantly improves survival in PA bacteremia and is associated with similar rates of bacteriological eradication in pneumonia and skin and soft tissue infection caused by PA compared to BL monotherapy. However, more research is needed to make meaningful clinical recommendations.

Antimicrobial resistance profiles and associated factors of Acinetobacter and Pseudomonas aeruginosa nosocomial infection among patients admitted at Dessie comprehensive specialized Hospital, North-East Ethiopia. A cross-sectional study

Introduction

Hospital admitted patients are at increased risk of nosocomial infections (NIs) with multi-drug resistant (MDR) pathogens which are prevalent in the hospital environment. Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter baumannii (A. baumannii) are common causes of NIs worldwide. The objective of this study is to determine antimicrobial resistance profiles and associated factors of Acinetobacter spp and P. aeruginosa NIs among hospitalized patients.

Methods

A cross-sectional study was conducted at Dessie comprehensive specialized hospital, North-East Ethiopia, from February 1 to April 30, 2020. A total of 254 patients who were suspected of the bloodstream, urinary tract, or surgical site nosocomial infections were enrolled consecutively. Socio-demographic and other variables of interest were collected using a structured questionnaire. Specimens were collected and processed following standard microbiological procedures. Antimicrobial susceptibility was determined using the Kirby-Bauer disk diffusion method following Clinical and Laboratory Standards Institute guidelines. Data were analyzed with SPSS version 23 and p-value < 0.05 was considered statistically significant.

Results

Overall, 13% of patients had nosocomial Acinetobacter spp and/or P. aeruginosa infections. The culture positivity rate was 16(6.3%) for Acinetobacter spp and 18(7.1%) for P. aeruginosa. Patients admitted in the surgical ward (Adjusted odds ratio (AOR):10.66;95% confidence interval (CI):1.22–93.23), pediatric ward (AOR:14.37;95%CI:1.4–148.5), intensive care unit (AOR:41.93;95%CI:4.7–374.7) and orthopedics (AOR:52.21;95%CI:7.5–365) were significantly at risk to develop NIs compared to patients admitted in the medical ward. Patients who took more than two antimicrobial types at admission were 94% (AOR:0.06; 95% CI:0.004–0.84) times more protected from NIs compared to those who did not take any antimicrobial. About 81% of Acinetobacter spp and 83% of P. aeruginosa isolates were MDR. Amikacin and meropenem showed promising activity against Acinetobacter spp and P. aeruginosa isolates.

Conclusion

The high prevalence of MDR Acinetobacter spp and P. aeruginosa nosocomial isolates enforce treating of patients with NIs based on antimicrobial susceptibility testing results.

Pseudomonas aeruginosa in Nepali hospitals: poor outcomes amid 10 years of increasing antimicrobial resistance

OBJECTIVE

To determine antimicrobial resistance patterns and prevalence of multi- (MDR, i.e., resistant to ⩾3 classes of antimicrobial agents) and extensively (XDR, i.e., resistant to ⩾3, susceptible to ⩽2 groups of antibiotics) drug-resistant strains of Pseudomonas aeruginosa.

METHODS

This was a cross-sectional study conducted in Nepal Mediciti Hospital, Lalitpur, Nepal, using standard microbiological methods with Kirby Bauer disc diffusion to identify antimicrobial susceptibility.

RESULTS

P. aeruginosa (n = 447) were most frequently isolated in respiratory (n = 203, 45.4%) and urinary samples (n = 120, 26.8%). AWaRe Access antibiotics showed 25-30% resistance, Watch antibiotics 30-55%. Susceptibility to AWaRe Reserve antibiotics remains high; however, 32.8% were resistant to aztreonam. Overall, 190 (42.5%) were MDR and 99 (22.1%) XDR (first Nepali report) based on mainly non-respiratory samples. The majority of infected patients were >40 years (n = 229, 63.2%) or inpatients (n = 181, 50.0%); 36 (15.2%) had an unfavourable outcome, including death (n = 25, 10.5%). Our larger study showed a failure of improvement over eight previous studies covering 10 years.

CONCLUSION

Antibiotic resistance in P. aeruginosa occurred to all 19 AWaRe group antibiotics tested. Vulnerable patients are at significant risk from such resistant strains, with a high death rate. Sustainable and acceptable antibiotic surveillance and control are urgently needed across Nepal, as antimicrobial resistance has deteriorated over the last decade.

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.

Emergence and Expansion of a Carbapenem-Resistant Pseudomonas aeruginosa Clone Are Associated with Plasmid-Borne bla KPC-2 and Virulence-Related Genes

Pseudomonas aeruginosa is a major opportunistic pathogen and one of the leading bacterial species causing health care-associated infections. Carbapenems are the most effective antimicrobial agents for the treatment of severe infections caused by P. aeruginosa However, our recent surveillance demonstrated that the prevalence of carbapenem-resistant P. aeruginosa (CRPA) reached 38.67% in Zhejiang, China. By analyzing CRPA isolates collected from patients from 2006 to 2018, we found that 33% of CRPA isolates carried the gene bla _KPC-2, which conferred high-level resistance to carbapenems and other β-lactams. In particular, a CRPA clone, ST463 (sequence type 463), emerged and has become the predominant CRPA clone among the population. Genome sequencing demonstrated that ST463 expansion was associated with plasmid-borne bla _KPC-2 The mobile element flanking bla _KPC-2, the type IV secretion system, and the successful expansion of clone ST463 might have further favored bla _KPC-2 spread in P. aeruginosa Molecular clock analysis dated the emergence of clone ST463 to around 2007. Genome-wide association analysis showed that 567 genes were associated with clone ST463, including several known virulence genes related to the biosynthesis of lipooligosaccharide (LOS) O-antigens and exotoxin. These findings indicate that ST463 is expanding with plasmid-borne bla _KPC-2 and virulence-related genes in nosocomial infections, and close surveillance should be undertaken in the future.IMPORTANCE Health care-associated infections, also known as nosocomial infections, are the most frequent adverse events in health care delivery worldwide, causing high rates of morbidity and mortality and high health care costs. Pseudomonas aeruginosa is one of the leading bacterial species causing health care-associated infections. Carbapenems are the most effective antimicrobial agents for the treatment of its severe infections. However, the prevalence of carbapenem-resistant P. aeruginosa (CRPA) has been increasing rapidly in recent years, and our surveillance demonstrated that the prevalence of CRPA reached 38.67% in Zhejiang, China. Genome sequencing of CRPA isolates over a decade showed that a CRPA clone (ST463) emerged recently. The clone is highly resistant to β-lactams, including carbapenems, and fluoroquinolones. Genome-wide association analysis showed that the clone expanded with virulence-related genes and the plasmid-borne carbapenem-resistant gene bla _KPC-2 These findings are of significant public health importance, as the information will facilitate the control and minimization of CRPA nosocomial infections.

Antimicrobial Polymeric Structures Assembled on Surfaces

Pathogenic microbes are the main cause of various undesired infections in living organisms, including humans. Most of these infections are favored in hospital environments where humans are being treated with antibiotics and where some microbes succeed in developing resistance to such drugs. As a consequence, our society is currently researching for alternative, yet more efficient antimicrobial solutions. Certain natural and synthetic polymers are versatile materials that have already proved themselves to be highly suitable for the development of the next-generation of antimicrobial systems that can efficiently prevent and kill microbes in various environments. Here, we discuss the latest developments of polymeric structures, exhibiting (reinforced) antimicrobial attributes that can be assembled on surfaces and coatings either from synthetic polymers displaying antiadhesive and/or antimicrobial properties or from blends and nanocomposites based on such polymers.

The healthcare costs of antimicrobial resistance in Lebanon: a multi-centre prospective cohort study from the payer perspective

Background

Our aim was to examine whether the length of stay, hospital charges and in-hospital mortality attributable to healthcare- and community-associated infections due to antimicrobial-resistant bacteria were higher compared with those due to susceptible bacteria in the Lebanese healthcare settings using different methodology of analysis from the payer perspective .

Methods

We performed a multi-centre prospective cohort study in ten hospitals across Lebanon. The sample size consisted of 1289 patients with documented healthcare-associated infection (HAI) or community-associated infection (CAI). We conducted three separate analysis to adjust for confounders and time-dependent bias: (1) Post-HAIs in which we included the excess LOS and hospital charges incurred after infection and (2) Matched cohort, in which we matched the patients based on propensity score estimates (3) The conventional method, in which we considered the entire hospital stay and allocated charges attributable to CAI. The linear regression models accounted for multiple confounders.

Results

HAIs and CAIs with resistant versus susceptible bacteria were associated with a significant excess length of hospital stay (2.69 days [95% CI,1.5–3.9]; p < 0.001) and (2.2 days [95% CI,1.2–3.3]; p < 0.001) and resulted in additional hospital charges ($1807 [95% CI, 1046–2569]; p < 0.001) and ($889 [95% CI, 378–1400]; p = 0.001) respectively. Compared with the post-HAIs analysis, the matched cohort method showed a reduction by 26 and 13% in hospital charges and LOS estimates respectively. Infections with resistant bacteria did not decrease the time to in-hospital mortality, for both healthcare- or community-associated infections. Resistant cases in the post-HAIs analysis showed a significantly higher risk of in-hospital mortality (odds ratio, 0.517 [95% CI, 0.327–0.820]; p = 0.05).

Conclusion

This is the first nationwide study that quantifies the healthcare costs of antimicrobial resistance in Lebanon. For cases with HAIs, matched cohort analysis showed more conservative estimates compared with post-HAIs method. The differences in estimates highlight the need for a unified methodology to estimate the burden of antimicrobial resistance in order to accurately advise health policy makers and prioritize resources expenditure.

Risk Factors for the Acquisition of Enterococcus faecium Infection and Mortality in Patients with Enterococcal Bacteremia: A 5-Year Retrospective Analysis in a Tertiary Care University Hospital

The incidence of bacteremia caused by Enterococcus faecium, which is highly resistant to multiple antibiotics, is increasing in Japan. However, risk factors for the acquisition of E. faecium infection and mortality due to enterococcal bacteremia are not well known. We compared demographic, microbiological, and clinical characteristics using a Cox regression model and univariate analysis. We performed a multivariate analysis to identify risk factors for patients treated between 2014 and 2018. Among 186 patients with enterococcal bacteremia, two groups included in the Kaplan–Meier analysis (E. faecalis (n = 88) and E. faecium (n = 94)) showed poor overall survival in the E. faecium group (HR: 1.92; 95% confidence interval: 1.01–3.66; p = 0.048). The median daily antibiotic cost per patient in the E. faecium group was significantly higher than that in the E. faecalis group ($23 ($13–$34) vs. $34 ($22–$58), p < 0.001). E. faecium strains were more frequently identified with previous use of antipseudomonal penicillins (OR = 4.04, p < 0.001) and carbapenems (OR = 3.33, p = 0.003). Bacteremia from an unknown source (OR = 2.79, p = 0.025) and acute kidney injury (OR = 4.51, p = 0.004) were associated with higher risks of 30-day mortality in patients with enterococcal bacteremia. Therefore, clinicians should provide improved medical management, with support from specialized teams such as those assisting antimicrobial stewardship programs.

Antimicrobial Property of Halogenated Catechols

Bacterial infection associated with multidrug resistance (MDR) bacteria is increasingly becoming a significant public health risk. Herein, we synthesized a series of halogenated dopamine methacrylamide (DMA), which contains a catechol side chain modified with either chloro-, bromo-, or iodo-functional group. Catechol is a widely used adhesive moiety for designing bioadhesives and coating. However, the intrinsic antimicrobial property of catechol has not been demonstrated before. These halogenated DMA were incorporated into hydrogels, copolymers, and coatings and exhibited more than 99% killing efficiencies against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. More importantly, hydrogel containing chlorinated DMA demonstrated broad-spectrum antimicrobial activities towards multiple MDR bacteria, which included methicillin resistant S. aureus (MRSA), vancomycin resistant enterococci (VRE), multi antibiotics resistant Pseudomonas aeruginosa (PAER), multi antibiotics resistant Acinetobacter baumannii (AB) and carbapenem resistant Klebsiella pneumoniae (CRKP). These hydrogels also demonstrated the ability to kill bacteria in a biofilm while exhibiting low cytotoxic. Based on molecular docking and molecular dynamics simulation, Cl-functionalized catechol can potentially inhibit bacterial fatty acid synthesis at the enoyl-acyl carrier protein reductase (FabI) step. The combination of moisture-resistant adhesive property, inherent antimicrobial property, and the versatility of incorporating halogenated DMA into different polymeric materials greatly enhanced the potential for using these monomers for designing multifunctional bioadhesives and coatings.

Design, synthesis and drug resistance reversal potential of novel curcumin mimics Van D: Synergy potential of curcumin mimics

Being crucial part of plant-based novel discovery of drug from natural resources, a study was done to explore the antibacterial potential of curcumin mimics in combination with antibiotics against multidrug resistant isolates of Pseudomonas aeruginosa. The best candidate Van D, a curcumin mimics reduced the MIC of tetracycline (TET) up to 16 folds against multidrug resistant clinical isolates. VanD further inhibited the efflux pumps as evident by ethidium bromide efflux and by in-silico docking studies. In another experiment, it was also found that Van D inhibits biofilm synthesis. This derivative kills the KG-P2, an isolate of P. aeruginosa in a time dependent manner, the post-antibiotic effect (PAE) of tetracycline was extended as well as mutant prevention concentration (MPC) of TET was also decreased. In Swiss albino mice, Van D reduced the proinflammatory cytokines concentration. In acute oral toxicity study, this derivative was well tolerated and found to be safe up to 1000 mg/kg dose. To the best of our knowledge, this is the first report on curcumin mimics as synergistic agent via inhibition of efflux pump.

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Pseudomonas æruginosa (PA) is among the major agents of infection in burns. Multidrug-resistant strains are commonly isolated, which hampers the management of these patients. Our purpose was to study the incidence density of PA colonization and PA infection and to investigate the antibiotic susceptibility of strains isolated in patients hospitalized in the Trauma and Burn Center's Burn Unit (TBC-BU) in Tunisia. It is a retrospective study including 1649 non-repetitive strains of PA during an 8-year period (2012- 2019). PA was the most common organism in TBC-BU bacterial ecology (15%). The incidence density of PA colonization and PA infection was 16.1‰ days of in-patient stay (DH) and 16.5‰ DH, respectively. A positive and statistically significant correlation was found between PA colonization and PA infection (rs=1; p=0,004). The colonization strains were mainly isolated from skin (25.1%) and central catheters (22.3%). Bacteremia was the most common infection (19.5%). The skin was the most common source of bacteremia (22.1%) followed by central catheters (18.3%). The highest rates of antibiotic resistance were found with piperacillin-tazobactam (72.4%), ceftazidime (49.4%), meropenem (74%), imipenem (70.5%), amikacin (74.6%), ciprofloxacin (56.5%) and fosfomycin (35.3%). We did not identify any colistin-resistant strain. The multidrug resistance rate was 78%. The metallo-carbapenemase-producing strains rate was 14.4%.

A Review on Antistaphylococcal Secondary Metabolites from Basidiomycetes

Fungi are a rich source of secondary metabolites with several pharmacological activities such as antifungal, antioxidant, antibacterial and anticancer to name a few. Due to the large number of diverse structured chemical compounds they produce, fungi from the phyla Ascomycota, Basidiomycota and Muccoromycota have been intensively studied for isolation of bioactive compounds. Basidiomycetes-derived secondary metabolites are known as a promising source of antibacterial compounds with activity against Gram-positive bacteria. The continued emergence of antimicrobial resistance (AMR) poses a major challenge to patient health as it leads to higher morbidity and mortality, higher hospital-stay duration and substantial economic burden in global healthcare sector. One of the key culprits for AMR crisis is Staphylococcus aureus causing community-acquired infections as the pathogen develops resistance towards multiple antibiotics. The recent emergence of community strains of S. aureus harbouring methicillin-resistant (MRSA), vancomycin-intermediate (VISA) and vancomycin-resistant (VRSA) genes associated with increased virulence is challenging. Despite the few significant developments in antibiotic research, successful MRSA therapeutic options are still needed to reduce the use of scanty and expensive second-line treatments. This paper provides an overview of findings from various studies on antibacterial secondary metabolites from basidiomycetes, with a special focus on antistaphylococcal activity.

Amending the Efficiency of Antimicrobials against Multidrug-Resistant Pseudomonas aeruginosa by Low-Frequency Magnetic Fields

We studied the effect of 1- and 2-h exposure to low-frequency magnetic fields (0.3 and 0.42 mT) on the sensitivity of Pseudomonas aeruginosa to 18 antibiotics. P. aeruginosa samples were obtained from 20 patients with burns. Exposure to magnetic field reduced the resistance of P. aeruginosa and increased their susceptibility to antimicrobial drugs. This increase was positively correlated with field intensity and duration of exposure. After 2-h exposure to 0.42 mT, susceptibility of P. aeruginosa to antimicrobial drugs aztreonam, ceftazidime, colistin, imipenem, levofloxacin, and meropenem significantly increased. In addition, resensitization of P. aeruginosa to carbapenems, penicillin, quinolones, and aminoglycosides groups was observed.

Factors favouring the evolution of multidrug resistance in bacteria

The evolution of multidrug antibiotic resistance in commensal bacteria is an important public health concern. Commensal bacteria such as Escherichia coli, Streptococcus pneumoniae or Staphylococcus aureus, are also opportunistic pathogens causing a large fraction of the community-acquired and hospital-acquired bacterial infections. Multidrug resistance (MDR) makes these infections harder to treat with antibiotics and may thus cause substantial additional morbidity and mortality. Here, we develop an evolutionary epidemiology model to identify the factors favouring the evolution of MDR in commensal bacteria. The model describes the evolution of antibiotic resistance in a commensal bacterial species evolving in a host population subjected to multiple antibiotic treatments. We combine statistical analysis of a large number of simulations and mathematical analysis to understand the model behaviour. We find that MDR evolves more readily when it is less costly than expected from the combinations of single resistances (positive epistasis). MDR frequently evolves when bacteria are in contact with multiple drugs prescribed in the host population, even if individual hosts are only treated with a single drug at a time. MDR is favoured when the host population is structured in different classes that vary in their rates of antibiotic treatment. However, under most circumstances, recombination between loci involved in resistance does not meaningfully affect the equilibrium frequency of MDR. Together, these results suggest that MDR is a frequent evolutionary outcome in commensal bacteria that encounter the variety of antibiotics prescribed in the host population. A better characterization of the variability in antibiotic use across the host population (e.g. across age classes or geographical location) would help predict which MDR genotypes will most readily evolve.

Intra-Abdominal Infections by Carbapenemase-Producing Enterobacteriaceae in a Surgical Unit: Counting Mortality, Stay, and Costs

Background: Carbapenemase-producing Enterobacteriaceae (CPE)-related infections are a problem in public health at present, including intra-abdominal infections (IAI) and surgical populations. The aim of this study was to determine mortality and related risk factors, length of stay (LOS,) and costs for CPE-IAI in surgical patients. Patients and Methods: Review of CPE-related IAI acquired during admission in a general surgery department from January 2013 to December 2018. A mortality analysis was performed specifically in patients with CPE-IAI, and a global analysis of IAI including patients with CPE-IAI (cases) and matched patients with IAI by non-resistant bacteria (controls). Results: Forty patients with CPE-IAI were included, OXA-48-producing Klebsiella pneumoniae was present in 85%. Global mortality rate at 30 days for CPE-IAI was 17.5%; mortality-related factors were: solid tumor (p = 0.009), metastatic disease (p = 0.005), immunodeficiency (p = 0.039), blood transfusion (p = 0.009), and septic shock (p = 0.011). Predictors related to mortality for IAI in the global analysis included age (p = 0.046), Charlson index (p = 0.036), CPE isolation (p = 0.003), and septic shock (p < 0.001). Median global LOS was 43 days (IQR 27-64) in patients with CPE-IAI, and 27 days (IQR 18-35) in controls (p < 0.001). Median global cost of admission was $31,671 (IQR 14,006-55,745) for patients with CPE-IAI and $20,306 (IQR 11,974-27,947) for controls (p = 0.064). The most relevant locations of underlying disease for CPE-IAI were: colorectal (32.5%) with 57-day LOS (IQR 34-65) and cost of $42,877 (IQR 18,780-92,607), and pancreas (25%) with 60-day LOS (IQR 32-99) and cost of $56,371 (IQR 32,590-113,979). Conclusion: Carbapenemase-producing Enterobacteriaceae-related IAI is associated with substantial mortality, LOS, and costs. Factors related to CPE-IAI mortality are solid tumor, metastatic disease, immunodeficiency, blood transfusion, and septic shock. Carbapenemase-producing Enterobacteriaceae isolation in IAI implies higher risk of mortality.

Pf Bacteriophage and Their Impact on Pseudomonas Virulence, Mammalian Immunity, and Chronic Infections

Pf bacteriophage are temperate phages that infect the bacterium Pseudomonas aeruginosa, a major cause of chronic lung infections in cystic fibrosis (CF) and other settings. Pf and other temperate phages have evolved complex, mutualistic relationships with their bacterial hosts that impact both bacterial phenotypes and chronic infection. We and others have reported that Pf phages are a virulence factor that promote the pathogenesis of P. aeruginosa infections in animal models and are associated with worse skin and lung infections in humans. Here we review the biology of Pf phage and what is known about its contributions to pathogenesis and clinical disease. First, we review the structure, genetics, and epidemiology of Pf phage. Next, we address the diverse and surprising ways that Pf phages contribute to P. aeruginosa phenotypes including effects on biofilm formation, antibiotic resistance, and motility. Then, we cover data indicating that Pf phages suppress mammalian immunity at sites of bacterial infection. Finally, we discuss recent literature implicating Pf in chronic P. aeruginosa infections in CF and other settings. Together, these reports suggest that Pf bacteriophage have direct effects on P. aeruginosa infections and that temperate phages are an exciting frontier in microbiology, immunology, and human health.

Identification of a Potential Inhibitor Targeting MurC Ligase of the Drug Resistant Pseudomonas aeruginosa Strain through Structure-Based Virtual Screening Approach and In Vitro Assay

BACKGROUND & OBJECTIVE

Pseudomonas aeruginosa shows resistance to a large number of antibiotics, including carbapenems and third generation cephalosporin. According to the World Health Organization global report published in February 2017, Pseudomonas aeruginosa is on the priority list among resistant bacteria, for which new antibiotics are urgently needed. Peptidoglycan serves as a good target for the discovery of novel antimicrobial drugs.

METHODS

Biosynthesis of peptidoglycan is a multi-step process involving four mur enzymes. Among these enzymes, UDP-N-acetylmuramate-L-alanine ligase (MurC) is considered to be an excellent target for the design of new classes of antimicrobial inhibitors in gram-negative bacteria.

RESULTS

In this study, a homology model of Pseudomonas aeruginosa MurC ligase was generated and used for virtual screening of chemical compounds from the ZINC Database. The best screened inhibitor i.e. N, N-dimethyl-2-oxo-2,3-dihydro-1H-1,3-benzodiazole-5-sulfonamide was then validated experimentally through inhibition assay.

CONCLUSION

The presented results based on combined computational and in vitro analysis open up new horizons for the development of novel antimicrobials against this pathogen.

Multi-drug resistance of blood stream, urinary tract and surgical site nosocomial infections of Acinetobacter baumannii and Pseudomonas aeruginosa among patients hospitalized at Felegehiwot referral hospital, Northwest Ethiopia: a cross-sectional study

BACKGROUND

Multi-drug resistant (MDR) Acinetobacter baumannii and Pseudomonas aeruginosa are major causes of nosocomial infections globally. They are the current World Health Organization critical priority pathogens for resistance, Antimicrobial resistance (AMR) surveillance and discovery of new antibiotics. However, there is paucity of data on nosocomial infections (NIs) caused by such superbugs in Ethiopia. Therefore, this study determined the magnitude and profile of nosocomial MDR A. baumannii and P. aeruginosa infections among patients hospitalized at Felegehiwot referral hospital, Northwest Ethiopia.

METHODS

A cross-sectional study was conducted at Felegehiwot referral hospital from April 1 to July 31, 2018. A total of 238 patients with blood stream, urinary tract and surgical site NIs were enrolled conveniently. Either blood, urine and wound swab specimens were collected and processed using standard bacteriological procedures. A. baumannii and P. aeruginosa isolates were identified using standard bacteriological techniques and confirmed by automated Vitek2 Compact. Antimicrobial susceptibility testing on isolates was performed using the disk diffusion technique. The results were interpreted as per the standard zone sizes of Clinical and Laboratory Standards Institute.Chi-square test was done to determine associations among variables. P value < 0.05 was considered statistical significant.

RESULTS

The median age of participants was 29 years. Overall,20(8.4%) of patients had nosocomial MDR A. baumannii and P. aeruginosa infections. The proportion of nosocomial MDR blood stream, urinary tract and surgical site infections were 13(8.9%), 5(8.3%) and 2 (6.3%), respectively. Patients with NI had lower mean age (24.9 years) (P = 0.035). All isolates of NIs were from patients with intravenous catheterization. The frequency of NI was 9(3.8%) for MDR A. baumannii and 11(4.6%) for MDR P.aeruginosa. A. baumannii and P. aeruginosa isolates were 100% MDR. All isolates of A. baumannii and P. aeruginosa were 100% resistant to ampicillin and piperacillin.A. baumannii isolates were 33.3 and 44.5% resistance against meropenem and ciprofloxacin, respectively while P.aeruginosa isolates revealed 36.4 and 45.5% resistance against ciprofloxacin and meropenem, respectively.

CONCLUSIONS

Health care associated infections of MDR A.baumannii and P. aeruginosa are critical problems in the study area. Therefore, urgent focused interventions required to contain the spreading of MDR NIs. Treatment of NIs for patients on health care should be guided by antimicrobial susceptibility testing.

Survey of isolation room equipment and resources in an academic hospital

PURPOSE

The purpose of this paper, a point prevalence study, is to quantify the incidence of isolation and identify the type of communicable diseases in isolation. The paper evaluates isolation precaution communication, availability of personal protective equipment (PPE) as well as other equipment necessary for maintaining isolation precautions.

DESIGN/METHODOLOGY/APPROACH

A standardised audit tool was developed in accordance with the National Standards for the Prevention and Control of Healthcare Associated Infections (May 2009). Data were collected from 14 March 2017 to 16 March 2017, through observation of occupied isolation rooms in an academic hospital in Dublin, Ireland. The data were subsequently used for additional analysis and discussion.

FINDINGS

In total, 14 per cent (125/869) of the total inpatient population was isolated at the time of the study. The most common isolation precaution was contact precautions (96.0 per cent). In all, 88 per cent of known contact precautions were due to multi-drug resistant organisms. Furthermore, 96 per cent of patients requiring isolation were isolated, 92.0 per cent of rooms had signage, 90.8 per cent had appropriate signs and 93.0 per cent of rooms had PPE available. Finally, 31 per cent of rooms had patient-dedicated and single-use equipment and 2.4 per cent had alcohol wipes available.

PRACTICAL IMPLICATIONS

The audit tool can be used to identify key areas of noncompliance associated with isolation and inform continuous improvement and education.

ORIGINALITY/VALUE

Currently, the rate of isolation is unknown in Ireland and standard guidelines are not established for the evaluation of isolation rooms. This audit tool can be used as an assessment for isolation room compliance.

Characterisation and risk factor profiling of Pseudomonas aeruginosa urinary tract infections: pinpointing those likely to be caused by multidrug-resistant strains

This study aimed to characterise UTIs caused by Pseudomonas aeruginosa in hospitalised adults and to identify risk factors for infections caused by multidrug-resistant (MDR) strains. A retrospective case-case-control study was conducted in two Italian teaching hospitals. Totally, 242 monomicrobial P. aeruginosa UTIs were analysed; 65 (26.9%) were caused by MDR strains. Clinical treatment failure at 72 h in 215 patients receiving empirical therapy was more frequent in MDR versus non-MDR cases [35/59 (59.3%) vs. 55/156 (35.3%); P = 0.001], particularly when a β-lactam/β-lactamase inhibitor or fluoroquinolone was initially prescribed. By Day 7 (when all regimens were consistent with antimicrobial susceptibility results), treatment failure rates were similar [MDR 15/65 (23.1%) vs. non-MDR 25/177 (14.1%); P = 0.09]. In-hospital mortality rates remained low in both groups [6/65 (9.2%) vs. 22/177 (12.4%); P = 0.49], but median hospital stay for MDR cases was longer (48 vs. 22 days; P ≤ 0.001). Models for predicting MDR and non-MDR P. aeruginosa UTIs displayed good discriminatory power. Presence of ≥3 risk factors for MDR P. aeruginosa UTI was associated with an OR for this outcome of 7.44 (95% CI 3.24-17.57; P < 0.001; specificity 91%, accuracy 75%). The model for predicting non-MDR P. aeruginosa UTI displayed similar accuracy (74%) with a risk factor burden threshold of ≥2 (OR = 7.02, 95% CI 4.61-10.70; P < 0.001). Risk factor assessment can identify UTIs in hospitalised patients likely to be caused by MDR P. aeruginosa, thereby facilitating targeted infection control and timelier effective treatment.

Pseudomonas aeruginosa in the ICU: prevalence, resistance profile, and antimicrobial consumption

INTRODUCTION

Pseudomonas aeruginosa is one of the main pathogens causing infection in intensive care units (ICUs) and usually presents antimicrobial resistance.

METHODS

Data were obtained from ICUs between 2010 and 2013.

RESULTS

P. aeruginosa had a prevalence of 14.5% of which 48.7% were multidrug resistant. We observed increasing resistance to carbapenems and polymyxin B and growing consumption of aminoglycosides, meropenem, ceftazidime, and polymyxin B. The regression impact between resistance and consumption was significant with respect to amikacin, imipenem, meropenem, and polymyxin B.

CONCLUSIONS

Monitoring antimicrobial consumption and resistant microorganisms should be reinforced to combat antimicrobial- and multi-drug resistance.

In situ synthesis of biocompatible imidazolium salt hydrogels with antimicrobial activity

Infection with antibiotic-resistant bacteria is becoming a significant public health risk. In this study, we synthesized a series of imidazolium salt (IMS)-containing polymers and hydrogels and tested their antimicrobial properties against both gram-positive (Staphylococcus aureus and MRSA) and gram-negative (Escherichia coli and PA01) bacteria. IMSs were either grafted as side chains or functionalized in the main chain of linear polymers, which demonstrated antimicrobial properties with minimum inhibitory concentrations as low as 2 μg/mL. Similarly, the optimized IMS-containing hydrogel effectively killed MRSA with a 96.1% killing efficiency and inhibited the growth of PA01. These hydrogels also demonstrated high performance in terms of mechanical property (compressive strength >2 MPa) and were noncytotoxic toward human dermal fibroblasts. STATEMENT OF SIGNIFICANCE: A series of polyimidazolium hydrogels were fabricated with acrylamide monomer and poly(ethylene glycol) dimethacrylate by thermal-initiated polymerization. These hydrogels completely killed methicillin-resistant Staphylococcus aureus and inhibited the growth of Pseudomonas aeruginosa. More importantly, these hydrogels demonstrated adequate mechanical property and biocompatibility. These antimicrobial hydrogels have the potential as biomaterials for preventing infections associated with multidrug-resistant bacteria.