Nosocomial urinary tract infections caused by Pseudomonas aeruginosa and Acinetobacter species: sensitivity to antibiotics and risk factors

Evaluating the Impact of Source-specific Order Sets for Sepsis on Empiric Antibiotic Selection in the Emergency Department

This retrospective cohort study found that implementing source-specific antibiotic order sets for sepsis in the emergency department increased appropriate empiric antibiotic selection from 51% to 74% (P = .01).

How to treat severe Acinetobacter baumannii infections

PURPOSE OF REVIEW

To update the management of severe Acinetobacter baumannii infections (ABI), particularly those caused by multi-resistant isolates.

RECENT FINDINGS

The in vitro activity of the various antimicrobial agents potentially helpful in treating ABI is highly variable and has progressively decreased for many of them, limiting current therapeutic options. The combination of more than one drug is still advisable in most circumstances. Ideally, two active first-line drugs should be used. Alternatively, a first-line and a second-line drug and, if this is not possible, two or more second-line drugs in combination. The emergence of new agents such as Cefiderocol, the combination of Sulbactam and Durlobactam, and the new Tetracyclines offer therapeutic options that need to be supported by clinical evidence.

SUMMARY

The apparent limitations in treating infections caused by this bacterium, the rapid development of resistance, and the serious underlying situation in most cases invite the search for alternatives to antibiotic treatment, the most promising of which seems to be bacteriophage therapy.

Study of Antimicrobial Resistance, Biofilm Formation, and Motility of Pseudomonas aeruginosa Derived from Urine Samples

Pseudomonas aeruginosa causes urinary tract infections associated with catheters by forming biofilms on the surface of indwelling catheters. Therefore, controlling the spread of the bacteria is crucial to preventing its transmission in hospitals and the environment. Thus, our objective was to determine the antibiotic susceptibility profiles of twenty-five P. aeruginosa isolates from UTIs at the Medical Center of Trás-os-Montes and Alto Douro (CHTMAD). Biofilm formation and motility are also virulence factors studied in this work. Out of the twenty-five P. aeruginosa isolates, 16% exhibited multidrug resistance, being resistant to at least three classes of antibiotics. However, the isolates showed a high prevalence of susceptibility to amikacin and tobramycin. Resistance to carbapenem antibiotics, essential for treating infections when other antibiotics fail, was low in this study, Notably, 92% of the isolates demonstrated intermediate sensitivity to ciprofloxacin, raising concerns about its efficacy in controlling the disease. Genotypic analysis revealed the presence of various β-lactamase genes, with class B metallo-β-lactamases (MBLs) being the most common. The bla_NDM, bla_SPM, and bla_VIM-VIM2 genes were detected in 16%, 60%, and 12% of the strains, respectively. The presence of these genes highlights the emerging threat of MBL-mediated resistance. Additionally, virulence gene analysis showed varying prevalence rates among the strains. The exoU gene, associated with cytotoxicity, was found in only one isolate, while other genes such as exoS, exoA, exoY, and exoT had a high prevalence. The toxA and lasB genes were present in all isolates, whereas the lasA gene was absent. The presence of various virulence genes suggests the potential of these strains to cause severe infections. This pathogen demonstrated proficiency in producing biofilms, as 92% of the isolates were found to be capable of doing so. Currently, antibiotic resistance is one of the most serious public health problems, as options become inadequate with the continued emergence and spread of multidrug-resistant strains, combined with the high rate of biofilm production and the ease of dissemination. In conclusion, this study provides insights into the antibiotic resistance and virulence profiles of P. aeruginosa strains isolated from human urine infections, highlighting the need for continued surveillance and appropriate therapeutic approaches.

Chicken IgY reduces the risk of Pseudomonas aeruginosa urinary tract infections in a murine model

Introduction

Urinary tract infections (UTIs) with Pseudomonas aeruginosa are a severe problem in disposed patients in modern healthcare. Pseudomonas aeruginosa establishes recalcitrant biofilm infections and can develop antibiotic resistance. Gargling with avian egg yolk anti-Pseudomonas antibodies (IgY) has shown clinical effect in preventing onset of chronic P. aeruginosa lung infections in patients with cystic fibrosis (CF). Therefore, we speculated whether passive intravesically administered IgY immunotherapy could be a novel strategy against P. aeruginosa UTIs.

Aim

To evaluate if prophylactic repurposing of anti-Pseudomonas IgY can prevent UTIs with P. aeruginosa in a UTI mouse model.

Materials and methods

In vitro, P. aeruginosa (PAO1 and PAO3) was mixed with increasing concentrations of specific anti-Pseudomonas IgY (sIgY) or non-specific control IgY (cIgY) and/or freshly isolated human neutrophils. Bacterial growth was evaluated by the optical density at 600 nm. In vivo, via a temporary transurethral catheter, 10-week-old female Balb/c mice were intravesically infected with 50 ml of a bacterial suspension and sIgY, cIgY, or isotonic NaCl. IgY and NaCl were either co-instilled with the bacteria, or instilled prophylactically, 30 min prior to infection. The animals were euthanized 20 h after infection. Vesical bacteriology was quantified, and cytokine expression in the bladder homogenate was measured by multiplex cytokine assay.

Results

In vitro, sIgY concentrations above 2.5% reduced bacterial growth in a dose-dependent manner. In vivo, a UTI lasting for minimum 7 days was established by installing 5 × 106 colony-forming units (CFU) of P. aeruginosa PAO1. sIgY reduced vesical bacterial load if co-installed with P. aeruginosa PAO1. Prophylactic sIgY and cIgY reduced bacterial load when compared to isotonic NaCl. CXCL2 and G-CSF were both increased in infected bladders compared to non-infected controls which had non-detectable levels. Co-installation of sIgY and bacteria nearly completely inhibited the inflammatory response. However, the cytokine levels in the bladder did not change after prophylactic administration of sIgY or cIgY.

Conclusion

Prophylactic sIgY significantly reduces the amount of bacteria in the bladder in a mouse model of P. aeruginosa cystitis and may serve as a novel non-antibiotic strategy in preventing P. aeruginosa UTIs.

Decreasing susceptibility of bacteria to ampicillin/ sulbactam and third generation cephalosporins in urinary tract infections

Background

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide and have become more difficult to treat over the years. Inappropriate antibiotic use has led to increased antibiotic resistance.

Materials and methods

We examined 1921 urine culture samples from a single hospital and analyzed them for bacterial spectrum and antibiotic susceptibility. We further analyzed changes in the rates of detected bacteria and of the sensitivity of these uropathogens to antibiotics over the years.

Results

In our hospital-based analysis, cystitis was the most frequently diagnosed UTI in women (76%) and men (79%). Escherichia coli (48%) was the most commonly identified uropathogen. Samples demonstrated an increase in the proportion of E. coli (p < 0.001) and a decrease in Enterococcus faecalis (p < 0.001) over the study time period. Antimicrobial susceptibility analysis showed an increase over time in the number of isolates with resistance to ampicillin/sulbactam (p < 0.001) and to third-generation cephalosporins cefotaxime (p = 0.043) and ceftazidime (p < 0.001).

Conclusions

Ampicillin/sulbactam and third-generation cephalosporins are antibiotics frequently used in the treatment of UTIs. When selecting an optimal antimicrobial treatment regimen for patients with UTIs, it is imperative to understand regional and timedependent differences in the prevalence of various uropathogens and antimicrobial resistance patterns. Therefore, continuous surveillance of local pathogen and antimicrobial susceptibility patterns for frequently used antibiotics should be prioritized.

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.

Cell adhesion and twitching motility influence strong biofilm formation in Pseudomonas aeruginosa

In the present study, biofilm formation was quantified in UTI isolates of Pseudomonas aeruginosa (n = 22) using the crystal violet assay and was categorized into; strong (n = 16), weak (n = 4), and moderate (n = 2) biofilm producers. Further experiments were done using strong (n = 4) and weak (n = 4) biofilm producers. Biofilm formation was greater in Luria broth followed by natural urine and artificial urine on silicone and silicone-coated latex. Cell adhesion and twitching motility were greater in strong biofilm producers. The presence of thick biofilm with an increased number of dead and total number of cells of strong biofilm producers was observed using CLSM. The concentrations of exopolymeric substances (eDNA, protein, and pel polysaccharide) were high in strong biofilm producers. FEG-SEM visualization of biofilm produced by strong biofilm producers showed more cells encased in thick biofilm matrix than weak ones. Overall results provide evidence for increased cell adhesion and twitching motility in strong biofilm producers.

Five-year Surveillance of Antimicrobial Resistance Changes and Epidemiological Characteristics in Pseudomonas aeruginosa: A Retrospective Study in a Chinese City Hospital

Background: In recent years, the widespread use of antibiotics has resulted in increased rates of antibiotic resistance (ABR). Pseudomonas aeruginosa is one of the most important opportunistic pathogens causing hospital-acquired infections. Pseudomonas aeruginosa has continuously increased resistance to commonly used clinical antimicrobial drugs, bringing great difficulties to clinical treatment. Objectives: This retrospective study investigated the epidemiological characteristics of P. aeruginosa and changes in ABR over a 5-year period at a hospital in Shandong Province, China. Methods: Pseudomonas aeruginosa strains were collected from 2015 to 2019. The antimicrobial susceptibility testing employed the Kirby-Bauer disk diffusion method and the broth microdilution method (VITEK-2 compact system), according to the guidelines by the Clinical and Laboratory Standards Institute. Data were analyzed using WHONET 5.6 and SPSS V. 21.0 software. Results: A total of 3,324 P. aeruginosa strains were isolated from clinical specimens (604, 631, 700, 595, and 794 strains from 2015 to 2019, respectively). The highest P. aeruginosa detection rates were from respiratory tract specimens (72.54%). The highest resistance was seen in aztreonam, followed by ciprofloxacin, levofloxacin, and imipenem. The isolation rates for carbapenem-resistant P. aeruginosa (CRPA) and multidrug-resistant P. aeruginosa (MDRPA) ranged from 15.21 - 18.38% and 17.31 - 27.31%, respectively. Also, the isolation rates for extensively drug-resistant P. aeruginosa (XDRPA) ranged from 1.86 - 3.52%. Conclusions: The main sources of the P. aeruginosa isolates were older adult patients with chronic respiratory diseases. The isolation rates for CRPA, MDRPA, and XDRPA strains decreased over the 5-year period. However, the drug resistance situation remains a serious concern. Hence, continued infection control and antimicrobial stewardship and basic and clinical research on bacterial resistance are essential.

Evaluation of Pseudomonas aeruginosa pathogenesis and therapeutics in military-relevant animal infection models

Modern combat-related injuries are often associated with acute polytrauma. As a consequence of severe combat-related injuries, a dysregulated immune response results in serious infectious complications. The gram-negative bacterium Pseudomonas aeruginosa is an opportunistic pathogen that often causes life-threatening bloodstream, lung, bone, urinary tract, and wound infections following combat-related injuries. The rise in the number of multidrug-resistant P. aeruginosa strains has elevated its importance to civilian clinicians and military medicine. Development of novel therapeutics and treatment options for P. aeruginosa infections is urgently needed. During the process of drug discovery and therapeutic testing, in vivo testing in animal models is a critical step in the bench-to-bedside approach, and required for Food and Drug Administration approval. Here, we review current and past literature with a focus on combat injury-relevant animal models often used to understand infection development, the interplay between P. aeruginosa and the host, and evaluation of novel treatments. Specifically, this review focuses on the following animal infection models: wound, burn, bone, lung, urinary tract, foreign body, and sepsis.

Bioinformatics analyses for the designation of a hybrid protein against urinary tract infections caused by Pseudomonas aeruginosa and investigation of the presence of pre-existing antibodies in infected humans

Pseudomonas aeruginosa is an important pathogen causing urinary tract infections (UTIs) and resistance to antibiotics has increased the need for a vaccine against this bacterium. P. aeruginosa V-antigen (PcrV), which is a component of the type III secretion system, delivers exoenzymes such as exoenzyme S (ExoS) into the host cells. In the present study, we aimed to design and express a hybrid protein composed of PcrV and ExoS from P. aeruginosa using bioinformatics. Finally, pre-existing antibodies were evaluated in sera collected from patients with UTI. The prediction results showed that the hybrid protein ExoS.PcrV had a C-score of -0.85 and Z-score of -5.55 versus C-score of -2.93 and Z-score of -2.65 for PcrV.ExoS. Based on BepiPred and ABCpred, 15 and 14 linear B-cell epitopes, as well as five conformational epitopes were identified in ExoS.PcrV. The interaction between the protein and immune receptor was validated in silico. Molecular docking indicated that the hybrid protein interacted strongly with Toll-like receptor 2. ExoS.PcrV was expressed in pET28a-BL21 and purified with a size of 57 kD by Nickel resins. The protein reacted with all sera collected from humans infected with P. aeruginosa following Western blot. The infected patients produced significantly higher IgG levels against the protein compared to the control as indicated by ELISA. The protein ExoS.PcrV was determined as a promising candidate against UTI caused by P. aeruginosa and the presence of pre-existing antibodies indicated the advantage of the hybrid protein. Evaluation of the efficacy of hybrid protein is ongoing in mice model. Communicated by Ramaswamy H. Sarma.

Infection factors related to nursing procedures in Intensive Care Units: a scoping review

OBJECTIVES

to identify and map the invasive procedures performed by nursing that can cause Healthcare-Associated Infections in patients in Intensive Care Units.

METHODS

this is a scoping review carried out in the first half of 2018, based on search for studies in national and international databases, in which 2,209 studies were found, of which 35 constituted the final sample. The data were analyzed and organized by simple descriptive statistics.

RESULTS

among the invasive procedures performed by nursing that provide Healthcare-Associated Infections, delayed bladder catheter was indicated in 34 (66.67%) studies, the nasogastric catheter in 10 (19.61%) and the nasoenteral catheter in two (03.92%).

CONCLUSIONS

in the face of such problems, better nursing planning and guidance for care in these invasive techniques becomes relevant and thus minimizes the incidence of infections.

Within-Host Microevolution of Pseudomonas aeruginosa Urinary Isolates: A Seven-Patient Longitudinal Genomic and Phenotypic Study

Background

Pseudomonas aeruginosa is responsible for up to 10% of healthcare associated urinary tract infections (UTI), which can be difficult to treat and can lead to bacterial persistence. While numerous whole genome sequencing (WGS) analyses have explored within-host genomic adaptation and microevolution of P. aeruginosa during cystic fibrosis (CF) infections, little is known about P. aeruginosa adaptation to the urinary tract.

Results

Whole genome sequencing was performed on 108 P. aeruginosa urinary isolates, representing up to five isolates collected from 2 to 5 successive urine samples from seven patients hospitalized in a French hospital over 48–488 days. Clone type single nucleotide polymorphisms (ctSNPs) analysis revealed that each patient was colonized by a single clone type (<6000 SNPs between two isolates) at a given time and over time. However, 0–126 SNPs/genome/year were detected over time. Furthermore, large genomic deletions (1–5% of the genome) were identified in late isolates from three patients. For 2 of them, a convergent deletion of 70 genes was observed. Genomic adaptation (SNPs and deletion) occurred preferentially in genes encoding transcriptional regulators, two-component systems, and carbon compound catabolism. This genomic adaptation was significantly associated with a reduced fitness, particularly in artificial urine medium, but no strict correlation was identified between genomic adaptation and biofilm formation.

Conclusion

This study provides the first insight into P. aeruginosa within-host evolution in the urinary tract. It was driven by mutational mechanisms and genomic deletions and could lead to phenotypic changes in terms of fitness and biofilm production. Further metabolomic and phenotypic analyses are needed to describe in-depth genotype-phenotype associations in this complex and dynamic host-environment.

Animal Models in the Evaluation of the Effectiveness of Phage Therapy for Infections Caused by Gram-Negative Bacteria from the ESKAPE Group and the Reliability of Its Use in Humans

The authors emphasize how extremely important it is to highlight the role played by animal models in an attempt to determine possible phage interactions with the organism into which it was introduced as well as to determine the safety and effectiveness of phage therapy in vivo taking into account the individual conditions of a given organism and its physiology. Animal models in which phages are used make it possible, among other things, to evaluate the effective therapeutic dose and to choose the possible route of phage administration depending on the type of infection developed. These results cannot be applied in detail to the human body, but the knowledge gained from animal experiments is invaluable and very helpful. We would like to highlight how useful animal models may be for the possible effectiveness evaluation of phage therapy in the case of infections caused by gram-negative bacteria from the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species) group of pathogens. In this review, we focus specifically on the data from the last few years.

A chalcone-based fluorescent responsive probe for selective detection of nitroreductase activity in bacteria

A new chalcone-based fluorescent turn-on probe (3c) responsive to nitroreductase (NTR) activity and its application toward the detection of bacteria are presented.

Developing Rapid Antimicrobial Susceptibility Testing for Motile/Non-Motile Bacteria Treated with Antibiotics Covering Five Bactericidal Mechanisms on the Basis of Bead-Based Optical Diffusometry

Rapid antimicrobial susceptibility testing (AST) is an effective measure in the treatment of infections and the prevention of bacterial drug resistance. However, diverse antibiotic types and bacterial characteristics have formed complicated barriers to rapid diagnosis. To counteract these limitations, we investigated the interactions between antibiotic-treated bacteria and functionalized microbeads in optical diffusometry. The conjugation with bacteria increased the effective microbead complex size, thereby resulting in a temporal diffusivity change. The yielded data were sorted and analyzed to delineate a pattern for the prediction of antimicrobial susceptibility. The outcome showed that a completed rapid AST based on the trend of microbead diffusivity could provide results within 3 h (2 h measurement + 1 h computation). In this research, we studied four bacterial strains, including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus, and six antibiotics. Despite the different inhibitory effects caused by various antibiotics, similar trends in diffusivity alteration for all susceptible and resistant cases in the last 40 min of the 2-h measurement period were deduced. In addition, the AST results obtained using optical diffusometry showed good agreement with those acquired from the commercial instrument and conventional culture methods. Finally, we conducted a single-blinded clinical test, and the sensitivity, specificity, and accuracy of the system reached 92.9%, 91.4%, and 91.8%, respectively. Overall, the developed optical diffusometry showcased rapid AST with a small sample volume (20 μL) and low initial bacterial count (10⁵ CFU/mL). This technique provided a promising way to achieve early therapy against microbial diseases in the future.

Hospital-acquired infections in the adult intensive care unit-Epidemiology, antimicrobial resistance patterns, and risk factors for acquisition and mortality

BACKGROUND

Acquisition of Hospital-acquired infections (HAIs) in intensive care units (ICUs) predispose patients to higher mortality rates and additional adverse events. Serbian adult ICUs are rarely investigated for HAIs. The aim of this study was to look into HAIs in an adult ICU and identify risk factors for acquisition of HAIs and mortality.

METHODS

This retrospective study included 355 patients hospitalized over a 2-year period. Patient characteristics, antimicrobial resistance patterns, and risk factors of acquisition and predictors of mortality in patients who had a HAI were examined.

RESULTS

HAIs were diagnosed in 32.7% of patients. Resistance rates > 50% were observed in all antimicrobials except for tigecycline (14%), colistin (9%), and linezolid (0%). Predictors of HAI acquisition were underlying viral CNS infections and invasive devices-urinary and central venous catheters, and nasogastric tubes. Diabetes mellitus and intubation (odds ratio 2.5 and 6.7, P = .042 and <.001) were identified as predictors for increased mortality in patients who had a HAI.

CONCLUSIONS

Prevalence of HAIs and resistance rates are high compared to ICUs in other European countries. Risk factors for both acquisition of HAI and mortality were identified. Large-scale studies are necessary to look at HAIs in adult ICUs in Serbia.

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.

Draft Genome Sequences of Two Pseudomonas aeruginosa Isolates from the Female Urogenital Tract

Pseudomonas aeruginosa is a Gram-negative bacterium that has the ability to survive in and readily adapt to a variety of environmental conditions. Here, we report 2 genome sequences of P. aeruginosa strains, UMB1046 and UMB5686, isolated from the female urogenital tract.

Community-onset Pseudomonas aeruginosa urinary sepsis in elderly people: Predictive factors, adequacy of empirical therapy and outcomes

Purpose To know the predictive factors for Pseudomonas aeruginosa (PA) urinary sepsis in hospitalised elderly patients coming from community, the adequacy of empirical antibiotic therapy and its outcomes. Methods Retrospective case-control study conducted between 2007 and 2017. Patients aged 65 years or older with PA urinary sepsis were included as cases. Three age-matched controls, with urinary sepsis caused by other microorganisms, were selected for each case. Predictors for PA urinary sepsis were determined by logistic regression analysis. Adequacy of empirical antibiotic therapy and outcomes were compared between both groups. Results A total of 332 patients, from which 83 were cases, were included. Predictive factors for PA urinary sepsis were as follows: male sex (OR 3.16, 95% CI 1.61-6.10; P < .001), urinary catheter (OR 3.25, 95% CI 1.73-6.11; P < .001) and healthcare-associated infection (OR 5.52, 95% CI 1.76 -17.29; P = .003). Inadequate empirical antimicrobial therapy (IEAT) and length of hospital stay were higher in PA group (42% vs 24%, P = .002; 7.45 ± 4.36 days vs 6.43 ± 3.82 days, P = .045, respectively), but mortality was not different (7.2% vs 8.8%, P = .648). Conclusions Pseudomonas aeruginosa urinary sepsis in elderly people was associated with male sex, urinary catheter and healthcare-associated infection. These infections had a higher rate of IEAT and a longer hospital stay than urinary sepsis caused by other microorganisms.

Genome Sequence of Pseudomonas Phage UMP151, Isolated from the Female Bladder Microbiota

A temperate bacteriophage, designated UMP151, was isolated from a Pseudomonas aeruginosa strain from a catheterized urine sample of a woman with overactive bladder (OAB) symptoms. The 41,303-bp genome sequence of Pseudomonas phage UMP151 exhibits sequence similarity to prophage and lytic phage sequences isolated from other areas of the human body.

Emergence of antibiotic resistance Pseudomonas aeruginosa in intensive care unit; a critical review

The emergence of antibiotic resistant bacteria in the healthcare is a serious concern. In the Healthcare premises precisely intensive care unit are major sources of microbial diversity. Recent findings have demonstrated not only microbial diversity but also drug resistant microbes largely habitat in ICU. Pseudomonas aeruginosa found as a part of normal intestinal flora and a significant pathogen responsible for wide range of ICU acquired infection in critically ill patients. Nosocomial infection associated with this organism including gastrointestinal infection, urinary tract infections and blood stream infection. Infection caused by this organism are difficult to treat because of the presence of its innate resistance to many antibiotics (β-lactam and penem group of antibiotics), and its ability to acquire further resistance mechanism to multiple class of antibiotics, including Beta-lactams, aminoglycosides and fluoroquinolones. In the molecular evolution microbes adopted several mechanism to maintain genomic plasticity. The tool microbe use for its survival is mainly biofilm formation, quorum sensing, and horizontal gene transfer and enzyme promiscuity. Such genomic plasticity provide an ideal habitat to grow and survive in hearse environment mainly antibiotics pressure. This review focus on infection caused by Pseudomonas aeruginosa, its mechanisms of resistance and available treatment options. The present study provides a systemic review on major source of Pseudomonas aeruginosa in ICU. Further, study also emphasizes virulence gene/s associated with Pseudomonas aeruginosa genome for extended drug resistance. Study gives detailed overview of antibiotic drug resistance mechanism.

Heterogeneous production of proteases from Brazilian clinical isolates of Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa is an important human pathogen that causes severe infections in a wide range of immunosuppressed patients. Herein, we evaluated the proteolytic profiles of 96 Brazilian clinical isolates of P. aeruginosa recovered from diverse anatomical sites.

METHODS

Cell-associated and extracellular proteases were evidenced by gelatin-SDS-PAGE and by the cleavage of soluble gelatin. Elastase was measured by using the peptide substrate N-succinyl-Ala-Ala-Ala-p-nitroanilide. The prevalence of elastase genes (lasA and lasB) was evaluated by PCR.

RESULTS

Bacterial extracts were initially applied on gelatin-SDS-PAGE and the results revealed four distinct zymographic profiles as follows: profile I (composed by bands of 145, 118 and 50kDa), profile II (118 and 50kDa), profile III (145kDa) and profile IV (118kDa). All the proteolytic enzymes were inhibited by EDTA, identifying them as metalloproteases. The profile I was the most detected in both cellular (79.2%) and extracellular (84.4%) extracts. Overall, gelatinase and elastase activities measured in the spent culture media were significantly higher (around 2-fold) compared to the cellular extracts and the production level varied according to the site of bacterial isolation. For instance, tracheal secretion isolates produced elevated amount of gelatinase and elastase measured in both cellular and extracellular extracts. The prevalence of elastase genes revealed that 100% isolates were lasB-positive and 85.42% lasA-positive. Some positive/negative correlations were showed concerning the production of gelatinase, elastase, isolation site and antimicrobial susceptibility.

CONCLUSION

The protease production was highly heterogeneous in Brazilian clinical isolates of P. aeruginosa, which corroborates the genomic/metabolic versatility of this pathogen.

Previous Antibiotic Exposure and Antimicrobial Resistance Patterns of Acinetobacter spp. and Pseudomonas aeruginosa Isolated from Patients with Nosocomial Infections

BACKGROUND

The alarming spread of antibiotic-resistant bacteria causing healthcare-associated infections has been extensively reported in recent medical literature.

AIMS

To compare trends in antimicrobial consumption and development of resistance among isolates of Acinetobacter spp. and Pseudomonas aeruginosa that cause hospital infections.

STUDY DESIGN

Cross-sectional study.

METHODS

A study was conducted in a tertiary healthcare institution in central Serbia, during the 7-year period between January 2009 and December 2015. The incidence rate of infections caused by Acinetobacter or Pseudomonas, as well as their resistance density to commonly used antibiotics, were calculated. Utilization of antibiotics was expressed as the number of defined daily doses per 1000 patient-days.

RESULTS

A statistically significant increase in resistance density in 2015 compared to the first year of observation was noted for Acinetobacter, but not for Pseudomonas, to third-generation cephalosporins (p=0.008), aminoglycosides (p=0.005), carbapenems (p=0.003), piperacillin/tazobactam (p=0.025), ampicillin/sulbactam (p=0.009) and tigecycline (p=0.048).

CONCLUSION

Our study showed that there is an association between the resistance density of Acinetobacter spp. and utilization of carbapenems, tigecycline and aminoglycosides. A multifaceted intervention is needed to decrease the incidence rate of Acinetobacter and Pseudomonas hospital infections, as well as their resistance density to available antibiotics.

Pseudomonas aeruginosa urinary tract infections in hospitalized patients: Mortality and prognostic factors

Background

The aim of this study was to analyze the mortality and predictors of 30-day mortality among hospitalized patients with Pseudomonas aeruginosa urinary tract infection (PAUTI) and the impact of antibiotic treatment on survival.

Methods

Patients admitted to our hospital with PAUTI or those diagnosed of PAUTI during hospitalization for other disease between September 2012 and September 2014 were included. Repeated episodes from the same patient were excluded. Database with demographic, clinical and laboratory ítems was created. Empirical and definitive antibiotic therapy, antimicrobial resistance and all-cause mortality at 30 and 90 days were included.

Results

62 patients were included, with a mean age of 75 years. 51% were male. Mortality was 17.7% at 30 days and 33.9% at 90 days. Factors associated with reduced survival at 30 days were chronic liver disease with portal hypertension (P<0,01), diabetes mellitus (P = 0,04) chronic renal failure (P = 0,02), severe sepsis or septic shock (P<0,01), Charlson index > 3 (P = 0.02) and inadequated definitive antibiotic treatment (P<0,01). Independent risk factors for mortality in multivariate analysis were advanced chronic liver disease (HR 77,4; P<0,01), diabetes mellitus (HR 3,6; P = 0,04), chronic renal failure (HR 4,1; P = 0,03) and inadequated definitive antimicrobial treatment (HR 6,8; P = 0,01).

Conclusions

PAUTI are associated with high mortality in hospitalized patients, which increases significantly in those with severe comorbidity such as chronic renal failure, advanced liver disease or diabetes mellitus. Inadequated antibiotic treatment is associated with poor outcome, which remarks the importance of adjusting empirical antibiotic treatment based on the microbiological susceptibility results.

Bacterial community composition of an urban river in the North West Province, South Africa, in relation to physico-chemical water quality

The aim of this study was to determine the impacts of anthropogenic disturbances on bacterial community composition in an urban river (Mooi River). Physico-chemical analysis, bacterial enumeration and 454-pyrosequencing were conducted on the Mooi River system upstream and downstream of an urban settlement in the North West Province, South Africa. Pyrosequencing and multivariate analysis showed that nutrient inputs and faecal pollution strongly impacted the physico-chemical and microbiological quality at the downstream sites. Also, bacterial communities showed higher richness and evenness at the downstream sites. Multivariate analysis suggested that the abundances of Betaproteobacteria, Epsilonproteobacteria, Acidobacteria, Bacteroidetes and Verrucomicrobia are related to temperature, pH, dissolved oxygen (DO), sulphate and chlorophyll-a levels. These results suggest that urbanisation caused the overall water quality of this river to deteriorate, which in turn affected the bacterial community composition. In addition, our work identified potential indicator groups that may be used to track faecal and organic pollution in freshwater systems.

Nosocomial Infections Caused by Acinetobacter baumannii: Are We Losing the Battle?

BACKGROUND

The incidence of nosocomial infections caused by multi-drug- and extended-drug resistant strains of Acinetobacter is constantly increasing all over the world, with a high mortality rate. We analyzed the in-hospital data on the sensitivity of Acinetobacter baumannii isolates and correlated them with antibiotic treatment and clinical outcomes of nosocomial infections over a 17-mo period.

METHODS

Retrospective analysis was performed at the Clinical Center "Bezanijska kosa," Belgrade, Serbia. Microbiologic data (number and sensitivity of A. baumannii isolates) and clinical data (medical records of 41 randomly selected patients who developed nosocomial infection caused by A. baumannii) were matched.

RESULTS

Acinetobacter baumannii, detected in 279 isolates and obtained from 19 patients (12% of all samples), was resistant to almost all antibiotics tested, including carbapenems, with the exception of colistin and tigecycline. It was obtained most often from the respiratory tract samples. Empiric treatment of the nosocomial infections (pneumonia in 75% of cases) involved cephalosporins, metronidazole, and carbapenems (80%, 66%, and 61% of patients, respectively), whereas tigecyclin and colistin were used primarily in targeted therapy (20% and 12% of patients, respectively). The mortality rate of patients treated empirically was significantly higher (p < 0.01), reaching 100% in the elderly.

CONCLUSIONS

Nosocomial A. baumannii infections represent a significant clinical problem because of their high incidence, lack of susceptibility to the most commonly used antibiotics, and the often inappropriate treatment, which favors the development of multi-drug-resistant strains.