Risk factors for Pseudomonas aeruginosa infections in Asia-Pacific and consequences of inappropriate initial antimicrobial therapy: A systematic literature review and meta-analysis

Morpholinium-based Ionic Liquids as Potent Antibiofilm and Sensitizing Agents for the Control of Pseudomonas aeruginosa

Rising antimicrobial resistance is a critical threat to worldwide public health. To address the increasing antibiotic tolerance, diverse antimicrobial agents are examined for their ability to decrease bacterial resistance. One of the most relevant and persistent human pathogens is Pseudomonas aeruginosa. Our study investigates the anti-biofilm and sensitizing activity of 12 morpholinium-based ionic liquids with herbicidal anions on four clinically relevant P. aeruginosa strains. Among all tested compounds, four ionic liquids prevented biofilm formation at sub-minimum inhibitory concentrations for all investigated strains. For the first time, we established a hormetic effect on biofilm formation for P. aeruginosa strains subjected to an ionic liquid treatment. Interestingly, while ionic liquids with 4,4-didecylmorpholinium [Dec2Mor]+ are more efficient against planktonic bacteria, 4-decyl-4-ethylmorpholinium [DecEtMor]+ showed more potent inhibition of biofilm formation. Ionic liquids with 4,4-didecylmorpholinium ([Dec2Mor]+) cations even induced biofilm formation by strain 39016 at high concentrations due to flocculation. Morpholinium-based ionic liquids were also shown to enhance the efficacy of commonly used antibiotics from different chemical groups. We demonstrate that this synergy is associated with the mode of action of the antibiotics.

Management strategies for severe Pseudomonas aeruginosa infections

PURPOSE OF REVIEW

This review focuses on the management of severe Pseudomonas aeruginosa infections in critically ill patients.

RECENT FINDINGS

Pseudomonas aeruginosa is the most common pathogen in intensive care; the main related infections are nosocomial pneumonias, then bloodstream infections. Antimicrobial resistance is common; despite new antibiotics, it is associated with increased mortality, and can lead to a therapeutic deadlock.

SUMMARY

Carbapenem resistance in difficult-to-treat P. aeruginosa (DTR-PA) strains is primarily mediated by loss or reduction of the OprD porin, overexpression of the cephalosporinase AmpC, and/or overexpression of efflux pumps. However, the role of carbapenemases, particularly metallo-β-lactamases, has become more important. Ceftolozane-tazobactam, ceftazidime-avibactam and imipenem-relebactam are useful against DTR phenotypes (noncarbapenemase producers). Other new agents, such as aztreonam-ceftazidime-avibactam or cefiderocol, or colistin, might be effective for carbapenemase producers. Regarding nonantibiotic agents, only phages might be considered, pending further clinical trials. Combination therapy does not reduce mortality, but may be necessary for empirical treatment. Short-term treatment of severe P. aeruginosa infections should be preferred when it is expected that the clinical situation resolves rapidly.

Empiric Anti-Pseudomonal β-Lactam Monotherapy Versus Fluoroquinolone Combination Therapy in Patients With Hospital-Acquired Pneumonia: A Multicenter Cohort Study With Propensity Score Matching

BACKGROUND

There is insufficient data on the benefits of empiric antibiotic combinations for hospital-acquired pneumonia (HAP). We aimed to investigate whether empiric anti-pseudomonal combination therapy with fluoroquinolones decreases mortality in patients with HAP.

METHODS

This multicenter, retrospective cohort study included adult patients admitted to 16 tertiary and general hospitals in Korea between January 1 and December 31, 2019. Patients with risk factors for combination therapy were divided into anti-pseudomonal non-carbapenem β-lactam monotherapy and fluoroquinolone combination therapy groups. Primary outcome was 30-day mortality. Propensity score matching (PSM) was used to reduce selection bias.

RESULTS

In total, 631 patients with HAP were enrolled. Monotherapy was prescribed in 54.7% (n = 345) of the patients, and combination therapy was prescribed in 45.3% (n = 286). There was no significant difference in 30-day mortality between the two groups (16.8% vs. 18.2%, P = 0.729) or even after the PSM (17.5% vs. 18.2%, P = 0.913). After the PSM, adjusted hazard ratio for 30-day mortality from the combination therapy was 1.646 (95% confidence interval, 0.782-3.461; P = 0.189) in the Cox proportional hazards model. Moreover, there was no significant difference in the appropriateness of initial empiric antibiotics between the two groups (55.0% vs. 56.8%, P = 0.898). The proportion of multidrug-resistant (MDR) pathogens was high in both groups.

CONCLUSION

Empiric anti-pseudomonal fluoroquinolone combination therapy showed no survival benefit compared to β-lactam monotherapy in patients with HAP. Caution is needed regarding the routine combination of fluoroquinolones in the empiric treatment of HAP patients with a high risk of MDR.

Cost-effectiveness of imipenem/cilastatin/relebactam for hospital-acquired and ventilator-associated bacterial pneumonia

Aim: This study evaluates the cost-effectiveness of imipenem/cilastatin/relebactam (IMI/REL) for treating hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP) in an 'early adjustment prescribing scenario'. Methods: An economic model was constructed to compare two strategies: continuation of empiric piperacillin/tazobactam (PIP/TAZ) versus early adjustment to IMI/REL. A decision tree was used to depict the hospitalization period, and a Markov model used to capture long-term outcomes. Results: IMI/REL generated more quality-adjusted life years than PIP/TAZ, at an increased cost per patient. The incremental cost-effectiveness ratio of $17,529 per QALY is below the typical US willingness-to-pay threshold. Conclusion: IMI/REL may represent a cost-effective treatment for payers and a valuable option for clinicians, when considered alongside patient risk factors, local epidemiology, and susceptibility data.

Evidence-Based Treatment of Pseudomonas aeruginosa Infections: A Critical Reappraisal

Multidrug-resistant (MDR)/extensively drug-resistant (XDR) Pseudomonas aeruginosa is emerging as a major threat related to adverse patient outcomes. The goal of this review is to describe evidence-based empiric and targeted treatment regimens that can be exploited when dealing with suspected or confirmed infections due to MDR/XDR P. aeruginosa. P. aeruginosa has inherent resistance to many drug classes, the capacity to form biofilms, and most importantly, the ability to quickly acquire resistance to ongoing treatments. Based on the presence of risk factors for MDR/XDR infections and local epidemiology, where large proportions of strains are resistant to classic beta-lactams, the recommended empirical treatment for suspected P. aeruginosa infections is based on ceftolozane-tazobactam or ceftazidime-avibactam. Where local epidemiology indicates low rates of MDR/XDR and there are no risk factors, a third or fourth generation cephalosporin can be used in the context of a "carbapenem-sparing" strategy. Whenever feasible, antibiotic de-escalation is recommended after antimicrobial susceptibility tests suggest that it is appropriate, and de-escalation is based on different resistance mechanisms. Cefiderocol and imipenem-cilastatin-relebactam withstand most resistance mechanisms and may remain active in cases with resistance to other new antibiotics. Confronting the growing threat of MDR/XDR P. aeruginosa, treatment choices should be wise, sparing newer antibiotics when dealing with a suspected/confirmed susceptible P. aeruginosa strain and choosing the right option for MDR/XDR P. aeruginosa based on specific types and resistance mechanisms.

Three-Year Evaluation of Pseudomonas aeruginosa Bacteremia in Patients Admitted to a University-Affiliated Hospital, Mashhad, Iran

Background: Pseudomonas aeruginosa is an opportunistic gram-negative pathogen that can cause infection in almost any body part. Objectives: We aimed to evaluate the characteristics of patients with P. aeruginosa bloodstream infection (BSI). Methods: In this cross-sectional study, we retrospectively evaluated the records of 35 patients with P. aeruginosa BSI admitted to the Imam Reza Hospital, Mashhad, Iran, during 2012 - 2015. Age, sex, clinical symptoms, risk factors, underlying diseases, and the antibiogram test results were recorded and compared between nosocomial and community-acquired infection (CAI) dead and alive patients using the chi-square test. Data were analyzed using SPSS software, version 21. Results: The patients had a mean age of 54.57 ± 20.75 years, with 19 of them being men (54.3%). Intubation was only required in the deceased group (N = 19; P = 0.014). Tachypnea was more frequent (63.2% vs. 13.2%, P = 0.003), and appropriate treatment was less frequent (27.8% vs. 66.7%; P = 0.02) in the deceased group compared to the control group. Most patients with nosocomial infection (N = 24) passed away (66.7%; P = 0.03). All nine patients with a history of burning had a nosocomial infection (P = 0.01). Shivering and decreased consciousness were more frequent in patients with CAI (both P = 0.03) than in other patients. The antibiogram test results showed high resistance to multiple antibiotics. Conclusions: Considering the high mortality rate of P. aeruginosa BSI and resistance to multiple antibiotics, it is necessary to pay greater attention to the prevention of nosocomial infection with this pathogen, especially in patients admitted to burn centers and those with specific clinical signs, like tachypnea and leukocytosis.

Prognostic Effects of Inappropriate Empirical Antimicrobial Therapy in Adults With Community-Onset Bacteremia: Age Matters

Background

Studies have reported the effects of delayed administration of appropriate antimicrobial therapy (AAT) on the short-term prognosis of patients with bloodstream infections; however, whether there is an age-related difference in these effects remains debated.

Methods

In this 4-year multicenter case-control study, patients with community-onset bacteremia were retrospectively categorized into the "middle-aged" (45-64 years), "old" (65-74 years), and "very old" (≥75 years) groups. Two methods were adopted to investigate the prognostic effects of delayed AAT in each age group. First, its effects were, respectively, investigated, after adjustment for the independent predictors of 30-day mortality. Second, patients in each age group were matched by the closest propensity-score (PS), which was calculated by independent predictors of mortality; the survival curves and Pearson chi-square tests were adopted to disclose its effects in each PS-matching group.

Results

Each hour of delayed AAT resulted in an average increase in the 30-day crude mortality rate of 0.2% (P = 0.03), 0.4% (P < 0.001), and 0.7% (P < 0.001) in middle-aged (968 patients), old (683), and very old (1,265) patients, after, respectively, adjusting the independent predictors of mortality in each group. After appropriate PS-matching, no significant proportion differences in patient demographics, bacteremia characteristics, severity of bacteremia and comorbidities, and 15-day or 30-day crude mortality rates were observed between three matched groups (582 patients in each group). However, significant differences in survival curves between patients with delayed AAT > 24 or >48 h and those without delayed administration were demonstrated in each age group. Furthermore, the odds ratios of 30-day mortality for delayed AAT > 24 or >48 h were 1.73 (P = 0.04) or 1.82 (P = 0.04), 1.84 (P = 0.03) or 1.95 (P = 0.02), and 1.87 (P = 0.02) or 2.34 (P = 0.003) in the middle-aged, old, and very old groups, respectively. Notably, the greatest prognostic impact of delayed AAT > 24 or >48 h in the very old group and the smallest impact in the middle-aged group were exhibited.

Conclusion

For adults (aged ≥45 years) with community-onset bacteremia, the delayed AAT significantly impacts their short-term survival in varied age groups and the age-related differences in its prognostic impact might be evident.

Antimicrobial Susceptibility Trends and Risk Factors for Antimicrobial Resistance in Pseudomonas aeruginosa Bacteremia: 12-Year Experience in a Tertiary Hospital in Korea

BACKGROUND

Infections caused by multidrug-resistant Pseudomonas aeruginosa (MDRPA) have been on the rise worldwide, and delayed active antimicrobial therapy is associated with high mortality. However, few studies have evaluated increases in P. aeruginosa infections with antimicrobial resistance and risk factors for such antimicrobial resistance in Korea. Here, we analyzed changes in antimicrobial susceptibility associated with P. aeruginosa bacteremia and identified risk factors of antimicrobial resistance.

METHODS

The medical records of patients with P. aeruginosa bacteremia who were admitted to a tertiary hospital between January 2009 and October 2020 were retrospectively reviewed. Antibiotic resistance rates were compared among the time periods of 2009-2012, 2013-2016, and 2017-2020 and between the intensive care unit (ICU) and non-ICU setting. Empirical antimicrobial therapy was considered concordant, if the organism was susceptible to antibiotics in vitro, and discordant, if resistant.

RESULTS

During the study period, 295 patients with P. aeruginosa bacteremia were identified. The hepatobiliary tract (26.8%) was the most common primary site of infection. The rates of carbapenem-resistant P. aeruginosa (CRPA), MDRPA, and extensively drug-resistant P. aeruginosa (XDRPA) were 24.7%, 35.9%, and 15.9%, respectively. XDRPA showed an increasing trend, and CRPA, MDRPA, and XDRPA were also gradually increasing in non-ICU setting. Previous exposure to fluoroquinolones and glycopeptides and urinary tract infection were independent risk factors associated with CRPA, MDRPA, and XDRPA. Previous exposure to carbapenems was an independent risk factor of CRPA. CRPA, MDRPA, and XDRPA were associated with discordant empirical antimicrobial therapy.

CONCLUSION

The identification of risk factors for antimicrobial resistance and analysis of antimicrobial susceptibility might be important for concordant empirical antimicrobial therapy in patients with P. aeruginosa bacteremia.

Molecular detection of gyrA and mexA genes in Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa is one of the types of bacteria that arises resistance toward fluoroquinolos antibiotics remarkably in recent years.

METHODS

Fifty P. aeruginosa isolates were isolated from one hundred clinical samples, investigated the antibiogram activity toward eight different groups of antibiotics. Screening about gyrA gene was done by conventional PCR further more qualitative gene expression of mexA gene was done by using Real-time PCR in 22 MDR isolates, furthermore Relative gene expression analysis of gyrA and mexA was done.

RESULTS

The rate of P. aeruginosa isolates was (41.6%) from total clinical samples, the antibiogram test showed high resistance toward Ceftazidime, Ciprofloxacin, Levofloxacin and Gentamicin (100%), while the sensitivity was observed towards colistin (100%). Screening of gyrA that was achieved by PCR technique showed 22 positive isolates. Furthermore, the 22 isolates appeared high expression level of the efflux pump resistance gene mexA and gyrA gene compared with housekeeping gene rspL gene within fold change ranging (0.18-36 and 1-28.84 respectively) with a mean of 18.46 ct and 18.59 (respectively).

CONCLUSIONS

All P. aeruginosa isolates were MDR with high level of efflux pump expression of mexA gene as well as gyrA gene.

Cost Effectiveness of Ceftolozane/Tazobactam Compared with Meropenem for the Treatment of Patients with Ventilated Hospital-Acquired Bacterial Pneumonia and Ventilator-Associated Bacterial Pneumonia

Introduction

The clinical efficacy and safety of ceftolozane/tazobactam for the treatment of ventilated hospital-acquired bacterial pneumonia (vHABP) and ventilator-associated bacterial pneumonia (VABP) has been demonstrated in the phase III randomised controlled trial ASPECT-NP. However, there are no published data on the cost-effectiveness of ceftolozane/tazobactam for vHABP/VABP. These nosocomial infections are associated with high rates of morbidity and mortality, and are increasingly complicated by growing rates of resistance and the inappropriate use of antimicrobials. This study is to assess the cost-effectiveness of ceftolozane/tazobactam compared with meropenem for the treatment of vHABP/VABP in a US hospital setting.

Methods

A short-term decision tree followed by a long-term Markov model was developed to estimate lifetime costs and quality-adjusted life-years associated with ceftolozane/tazobactam and meropenem in the treatment of patients with vHABP/VABP. Pathogen susceptibility and clinical efficacy were informed by the Program to Assess Ceftolozane/Tazobactam Susceptibility (PACTS) database and ASPECT-NP, respectively. A US healthcare sector perspective was adopted, capturing direct costs borne by third-party payers or integrated health systems, and direct health effects for patients.

Results

In the confirmed treatment setting (post-susceptibility results), the incremental cost-effectiveness ratio for ceftolozane/tazobactam compared to meropenem was US$12,126 per quality-adjusted life-year (QALY); this reduced when used in the early treatment setting (before susceptibility results) at $4775/QALY.

Conclusion

Ceftolozane/tazobactam represents a highly cost-effective treatment option for patients with vHABP/VABP versus meropenem when used in either the confirmed or early treatment setting; with increased cost-effectiveness shown in the early setting.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00436-4.

Advances in Understanding of the Copper Homeostasis in Pseudomonas aeruginosa

Thirty-five thousand people die as a result of more than 2.8 million antibiotic-resistant infections in the United States of America per year. Pseudomonas aeruginosa (P. aeruginosa) is classified a serious threat, the second-highest threat category of the U.S. Department of Health and Human Services. Among others, the World Health Organization (WHO) encourages the discovery and development of novel antibiotic classes with new targets and mechanisms of action without cross-resistance to existing classes. To find potential new target sites in pathogenic bacteria, such as P. aeruginosa, it is inevitable to fully understand the molecular mechanism of homeostasis, metabolism, regulation, growth, and resistances thereof. P. aeruginosa maintains a sophisticated copper defense cascade comprising three stages, resembling those of public safety organizations. These stages include copper scavenging, first responder, and second responder. Similar mechanisms are found in numerous pathogens. Here we compare the copper-dependent transcription regulators cueR and copRS of Escherichia coli (E. coli) and P. aeruginosa. Further, phylogenetic analysis and structural modelling of mexPQ-opmE reveal that this efflux pump is unlikely to be involved in the copper export of P. aeruginosa. Altogether, we present current understandings of the copper homeostasis in P. aeruginosa and potential new target sites for antimicrobial agents or a combinatorial drug regimen in the fight against multidrug resistant pathogens.

Evaluation of efflux pump activity and biofilm formation in multidrug resistant clinical isolates of Pseudomonas aeruginosa isolated from a Federal Medical Center in Nigeria

Background

Pseudomonas aeruginosa an opportunistic pathogen, is widely associated with nosocomial infections and exhibits resistance to multiple classes of antibiotics. The aim of this study was to determine the antibiotic resistance profile, biofilm formation and efflux pump activity of Pseudomonas strains isolated from clinical samples in Abeokuta Ogun state Nigeria.

Methods

Fifty suspected Pseudomonas isolates were characterized by standard biochemical tests and PCR using Pseudomonas species -specific primers. Antibiotic susceptibility testing was done by the disc diffusion method. Efflux pump activity screening was done by the ethidium bromide method and biofilm formation assay by the tissue plate method. Genes encoding biofilm formation (pslA & plsD) and efflux pump activity (mexA, mexB and oprM) were assayed by PCR.

Results

Thirty-nine Pseudomonas spp. were identified of which 35 were Pseudomonas aeruginosa and 4 Pseudomonas spp. All 39 (100%) Pseudomonas isolates were resistant to ceftazidime, cefuroxime and amoxicillin-clavulanate. Thirty-six (92%), 10(25.6%), 20 (51.2%), 11(28%) and 9(23%) of the isolates were resistant to nitrofurantoin, imipenem, gentamicin, cefepime and aztreonam respectively. All the isolates had the ability to form biofilm and 11 (28%) of them were strong biofilm formers. They all (100%) harboured the pslA and pslD biofilm encoding genes. Varied relationships between biofilm formation and resistance to ciprofloxacin, ofloxacin, cefixime, gentamicin, imipenem, and aztreonam were observed. Only 23(59%) of the Pseudomonas isolates phenotypically exhibited efflux pump activity but mexA gene was detected in all 39 (100%) isolates while mexB and oprM genes were detected in 91%, 92%, and 88% of strong, moderate and weak biofilm formers respectively.

Conclusion

Multidrug resistance, biofilm and efflux pump capabilities in Pseudomonas aeruginosa have serious public health implications in the management of infections caused by this organism.

Futuristic Non-antibiotic Therapies to Combat Antibiotic Resistance: A Review

The looming problem of resistance to antibiotics in microorganisms is a global health concern. The drug-resistant microorganisms originating from anthropogenic sources and commercial livestock farming have posed serious environmental and health challenges. Antibiotic-resistant genes constituting the environmental "resistome" get transferred to human and veterinary pathogens. Hence, deciphering the origin, mechanism and extreme of transfer of these genetic factors into pathogens is extremely important to develop not only the therapeutic interventions to curtail the infections, but also the strategies to avert the menace of microbial drug-resistance. Clinicians, researchers and policymakers should jointly come up to develop the strategies to prevent superfluous exposure of pathogens to antibiotics in non-clinical settings. This article highlights the present scenario of increasing antimicrobial-resistance in pathogenic bacteria and the clinical importance of unconventional or non-antibiotic therapies to thwart the infectious pathogenic microorganisms.

Risk Factors and Outcomes of Antibiotic-resistant Pseudomonas aeruginosa Bloodstream Infection in Adult Patients With Acute Leukemia

BACKGROUND

Pseudomonas aeruginosa (PA) bloodstream infection (BSI) is a common complication in patients with acute leukemia (AL), and the prevalence of antibiotic-resistant strains poses a serious problem. However, there is limited information regarding antibiotic resistance, clinical characteristics, and outcomes of PA BSI in AL patients. This study explored characteristics associated with the clinical outcomes of AL patients with PA BSI and analyzed factors associated with BSI caused by multidrug-resistant (MDR) or carbapenem-resistant strains.

METHODS

This single-center retrospective study enrolled hospitalized AL patients who developed PA BSI during January 2014-December 2019. The Kaplan-Meier method was used to plot survival curves. Multivariate logistic regression analyses were also performed.

RESULTS

Of 293 eligible patients with PA BSI, 55 (18.8%) received inappropriate empirical antibiotic therapy within 48 hours of BSI onset, whereas up to 65.8% MDR-PA BSI patients received inappropriate empirical treatment. The 30-day mortality rate was 8.5% for all patients. However, the 30-day mortality rates were 28.9% and 5.5% in MDR-PA BSI and non-MDR-PA BSI patients, respectively (P < .001). On multivariate analysis, previous use of quinolones (odds ratio [OR], 5.851 [95% confidence interval {CI}, 2.638-12.975]) and piperacillin/tazobactam (OR, 2.837 [95% CI, 1.151-6.994]) were independently associated with MDR-PA BSI; and MDR-PA BSI (OR, 7.196 [95% CI, 2.773-18.668]), perianal infection (OR, 4.079 [95% CI, 1.401-11.879]), pulmonary infection (OR, 3.028 [95% CI, 1.231-7.446]), and age ≥55 years (OR, 2.871 [95% CI, 1.057-7.799]) were independent risk factors for 30-day mortality.

CONCLUSIONS

MDR increases mortality risk in PA BSI patients, and previous antibiotic exposure is important in MDR-PA BSI development. Rational antibiotic use based on local antimicrobial susceptibility and clinical characteristics can help reduce antibiotic resistance and mortality.

Epidemiology and risk factors for healthcare-associated infections caused by Pseudomonas aeruginosa

Pseudomonas aeruginosa (PA) is a globally recognized cause of healthcare-associated infections (HAIs). The aim of our cross-sectional study, conducted in a Serbian tertiary care hospital, was to investigate clinical characteristics of HAIs caused by the PA, the prevalence of various drug-resistant phenotypes of this pathogen, and risk factors for their occurrence. Prolonged ICU stay and previous carbapenem administration were independent risk factors for HAIs caused by carbapenem-resistant PA, while HAIs caused by multidrug-resistant PA were more frequent in patients with prolonged stay in an ICU, who were previously hospitalized at another department and previously treated with aminoglycosides, fluoroquinolones or glycopeptides. The prolonged ICU stay was the only significant risk factor for HAIs caused by extensively drug-resistant PA. To decrease the incidence of HAIs caused by drug-resistant PA, a multifaceted approach is necessary, including staff education, antibiotic stewardship, improving hygiene, shortening hospitalization, and minimizing exposure to invasive medical procedures/devices.

Pseudomonas infections among hospitalized adults in Latin America: a systematic review and meta-analysis

Background

Treatment of resistant Pseudomonas aeruginosa infection continues to be a challenge in Latin American countries (LATAM). We synthesize the literature on the use of appropriate initial antibiotic therapy (AIAT) and inappropriate initial antibiotic therapy (IIAT) in P. aeruginosa infections, and the literature on risk factors for acquisition of resistant P. aeruginosa among hospitalized adult patients in LATAM.

Methods

MEDLINE, EMBASE, Cochrane, and LILAC were searched between 2000 and August 2019. Abstracts and full-text articles were screened in duplicate. Random effects meta-analysis was conducted when studies were sufficiently similar.

Results

The screening of 165 citations identified through literature search yielded 98 full-text articles that were retrieved and assessed for eligibility, and 19 articles conducted in Brazil (14 articles), Colombia (4 articles), and Cuba (1 article) met the inclusion criteria. Of 19 eligible articles, six articles (840 subjects) examined AIAT compared to IIAT in P. aeruginosa infections; 17 articles (3203 total subjects) examined risk factors for acquisition of resistant P. aeruginosa; and four articles evaluated both. Four of 19 articles were rated low risk of bias and the remaining were deemed unclear or high risk of bias. In meta-analysis, AIAT was associated with lower mortality for P. aeruginosa infections (unadjusted summary OR 0.48, 95% CI 0.28–0.81; I² = 59%), compared to IIAT and the association with mortality persisted in subgroup meta-analysis by low risk of bias (3 articles; unadjusted summary OR 0.46, 95% CI 0.28–0.81; I² = 0%). No meta-analysis was performed for studies evaluating risk factors for acquisition of resistant P. aeruginosa as they were not sufficiently similar. Significant risk factors for acquisition of resistant P. aeruginosa included: prior use of antibiotics (11 articles), stay in the intensive care unit (ICU) (3 articles), and comorbidity score (3 articles). Outcomes were graded to be of low strength of evidence owing to unclear or high risk of bias and imprecise estimates.

Conclusion

Our study highlights the association of AIAT with lower mortality and prior use of antibiotics significantly predicts acquiring resistant P. aeruginosa infections. This review reinforces the need for rigorous and structured antimicrobial stewardship programs in the LATAM region.

Guidelines of the Association of Anesthesiologists-Intensivists, the Interregional Non-Governmental Organization Alliance of Clinical Chemotherapists and Microbiologists, the Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy (IACMAC), and NGO Russian Sepsis Forum Diagnostics and antimicrobial therapy of the infections caused by multiresistant microorganisms

Introduction. Strains of microorganisms resistant to antimicrobial agents are commonly found in medical units throughout most regions of the world, including Russia. This leads to lower antimicrobial therapy efficacy when treating nosocomial infections. In this regard, the timely implementation of adequate antibiotic therapy is of great importance.

The objective of the guidelines: To provide summarized information on contemporary approaches to microbiological diagnostics and the assessment of results, as well as the principles of rational use of antimicrobial and antifungal agents, including treatment of infections caused by multiple drug-resistant strains of microorganisms.

Subjects and methods. These guidelines are based on published data obtained in the course of randomized trials, as well as information presented in the provisions of international guidelines supported by high-level evidence. The guidelines were prepared by a working group of Russian experts with extensive experience in research and practical work in this area. On October 11, 2019, the final version of the guidelines was reviewed and approved at a joint meeting of the working group and representatives of the public organizations which initiated the development of these guidelines (Association of Anesthesiologists-Intensivists, the Interregional Non-Governmental Organization Alliance of Clinical Chemotherapists and Microbiologists, the Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy (IACMAC), NGO Russian Sepsis Forum).

Conclusion. The guidelines reflect an interdisciplinary consensus of approaches to the diagnostics and antibiotic therapy of infections caused by multiresistant microorganisms. The provisions set forth should be used to decide on the strategy of empirical and etiotropic therapy of the most severe infections.

Avaliação do uso de soros antivenenos na emergência de um hospital público regional de Vitória da Conquista (BA), Brasil

Resumo O presente estudo tem como objetivo caracterizar o perfil epidemiológico de vítimas de acidentes escorpiônicos e ofídicos e avaliar a adequação das prescrições de soros antivenenos. Estudo transversal cujas fontes de dados foram as fichas de notificação de acidentes por animais peçonhentos do Sistema de Informação de Agravos de Notificação no município de Vitória da Conquista (BA), Brasil. Foram incluídas as informações de acidentes escorpiônicos ou ofídicos no período entre julho de 2016 e junho de 2017 atendidos no município. Os dados obtidos e as variáveis de interesse foram analisadas de acordo com as perguntas deste estudo. No período observado foram atendidas 293 vítimas de acidentes por animais peçonhentos. Destas, 149 (50,9%) foram homens e 114 (38,9%) possuíam entre 20 a 59 anos. Foram 235 (80,9%) casos de escorpionismo e 58 (19,1%) de ofidismo. Destes, 203 (69,3%) foram classificados como leves e em 200 (68,5%) casos foi prescrita soroterapia para estes pacientes. Quanto à adequação das prescrições, 172 (59,7%) foram julgadas inadequadas e destas, o uso de número de ampolas acima do indicado foi a mais frequente. A prescrição inapropriada de soros antivenenos ocorreu em aproximadamente em 60% dos casos avaliados. Apesar disso, a maioria dos acidentes foi classificada como leve, em homens jovens.

Epidemiology, Treatment, and Prevention of Nosocomial Bacterial Pneumonia

Septicaemia likely results in high case-fatality rates in the present multidrug-resistant (MDR) era. Amongst them are hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), two frequent fatal septicaemic entities amongst hospitalised patients. We reviewed the PubMed database to identify the common organisms implicated in HAP/VAP, to explore the respective risk factors, and to find the appropriate antibiotic choice. Apart from methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa, extended-spectrum β-lactamase-producing Enterobacteriaceae spp., MDR or extensively drug-resistant (XDR)-Acinetobacter baumannii complex spp., followed by Stenotrophomonas maltophilia, Chryseobacterium indologenes, and Elizabethkingia meningoseptica are ranked as the top Gram-negative bacteria (GNB) implicated in HAP/VAP. Carbapenem-resistant Enterobacteriaceae notably emerged as an important concern in HAP/VAP. The above-mentioned pathogens have respective risk factors involved in their acquisition. In the present XDR era, tigecycline, colistin, and ceftazidime-avibactam are antibiotics effective against the Klebsiella pneumoniae carbapenemase and oxacillinase producers amongst the Enterobacteriaceae isolates implicated in HAP/VAP. Antibiotic combination regimens are recommended in the treatment of MDR/XDR-P. aeruginosa or A. baumannii complex isolates. Some special patient populations need prolonged courses (>7-day) and/or a combination regimen of antibiotic therapy. Implementation of an antibiotic stewardship policy and the measures recommended by the United States (US) Institute for Healthcare were shown to decrease the incidence rates of HAP/VAP substantially.

Activity of ceftolozane/tazobactam against a collection of Pseudomonas aeruginosa isolates from bloodstream infections in Australia

Pseudomonas aeruginosa is a common pathogen causing nosocomial infection. In particular, bloodstream infection (BSI) is associated with a high rate of morbidity and mortality. Ceftolozane/tazobactam is a new β-lactam/β-lactamase antimicrobial with activity against P. aeruginosa as well as multidrug resistant (MDR) Gram negative Enterobacteriaceae. Ceftolozane/tazobactam has frequently been used in salvage therapy for MDR P. aeruginosa infections. The aim of this study was to determine the activity of ceftolozane/tazobactam against P. aeruginosa isolates from BSIs collected from three clinical microbiology laboratories in Queensland, Australia, with a high proportion of isolates demonstrating β-lactam resistance. Antimicrobial susceptibility testing was performed by broth microdilution using custom made sensititre plates sourced from ThermoFisher Scientific. In addition to ceftolozane/tazobactam, we also tested piperacillin/tazobactam, ceftazidime, cefepime, meropenem, doripenem, imipenem, aztreonam, ciprofloxacin, levofloxacin, gentamicin, amikacin, tobramycin and colistin. Overall, ceftolozane/tazobactam was the most active agent tested [(MIC_50/90 = 1/2 μg/mL, 96% susceptible (S)]. Against 44 isolates with resistance to at least one other β-lactam agent, 40 were susceptible to ceftolozane/tazobactam. Three ceftolozane/tazobactam resistant isolates were susceptible to colistin, with one of those isolates also susceptible to levofloxacin but not to any other antimicrobials tested. One ceftolozane/tazobactam resistant isolate was susceptible only to meropenem and doripenem but was non-susceptible to imipenem. An association was found between fluoroquinolone resistance and aminoglycoside resistance but not with β-lactam resistance. In summary, ceftolozane/tazobactam was active against most strains tested, including those resistant to other β-lactams. Laboratories should consider testing P. aeruginosa against ceftolozane/tazobactam in suspected MDR or extensively drug resistant (XDR) infections.

Gram-negative infections: evolving treatments with expanding options

Antibiotic resistance was a major topic of interest for the nearly 13,000 physicians, microbiologists and scientists who attended European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) 2018. Much discussion centered round the potential benefits of novel antibiotics that are either already approved or under investigation in the treatment of infections caused by resistant Gram-negative pathogens. There was also general acceptance of the importance of ensuring that antibiotic stewardship is implemented in every ward throughout every hospital to ensure that these novel drugs are used appropriately and to combat the development of resistance.