Resistant Pseudomonas Research Articles

Selenium Resistant Bacilli and Pseudomonas as Potential Candidate for Selenium and Iron Biofortification in Maize Plants

Selenium is an essential element and is required in minute quantities for performing vital functions in living cells. Food is the ultimate source of selenium for animal and human populations. Crops, such as maize, which are used as food and feed, can be biofortified with selenium to alleviate selenium deficiency in both populations. The current study was conducted to isolate selenium-resistant bacteria from soil samples. Isolated bacteria were characterized on a morphological and biochemical basis. For specie level classification, 16S rRNA sequences were obtained. Isolated strains belonged to Bacillus halotolerans (TM3),Pseudomonas protegens (TM5), and Bacillus endophyticus (TM7). In-vitro PGPB characterization showed that some of the strains can produce IAA, Ammonia, HCN, and phosphate solubilization enzymes. Greenhouse pot experiments showed that the isolates enhanced seed germination rate, shoot length, and plant dry weight. Selenium supplementation caused decreased growth, but its effect was mitigated by the inoculation of isolated bacteria. Inoculation of these bacteria enhanced selenium content in maize leaves and shoots, ranging from 6-7%, while the addition of selenium to the soil increased selenium content by 300%. The iron content of maize leaves was also increased up to 17% in the inoculated strains.

Diagnostic Characterisation of Various Phenotypic Methods for Class-A Extended Spectrum of β-Lactamase among Multidrug Resistant Pseudomonas Aeruginosa Isolated from Diabetic Patients

Introduction: Pseudomonas aeruginosa often causes nosocomial infection, especially in high risk group patients like diabetics. It shows a high degree of resistance to broad spectrum of antibiotics due to its high adaptabtibility in hospital settings, so their infections are difficult to treat. Extended Spectrum β-Lactamase (ESBL) enzymes confer resistance to most of the β-lactam antibiotics, including penicillin, cephalosporins and monobactams. Aim: To identify ESBL producing strains among Multidrug Resistant (MDR) Pseudomonas aeruginosa isolated from diabetes patients using various phenotypic methods with their performance characteristics. Materials and Methods: An observational descriptive crosssectional study was conducted in the Department of Microbiology at Sawai Man Singh Medical College, Jaipur, Rajasthan, India, from April 2017 to March 2019. Various clinical samples received from diabetic patients were cultured and P. aeruginosa were identified as per standard protocol. Antimicrobial susceptibility testing was done according to Clinical and Laboratory Standards Institute (CLSI) guidelines. ESBL producing MDR P. aeruginosa was detected by using standard Epsilometer test (E test), Phenotypic Confirmatory Disc Diffusion Test (PCDDT) and Double Disc Synergy Test (DDST). Test characteristics sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) and accuracy were calculated. Kappa coefficient was used to show diagnostic agreement between the tests. Results: A total 430 clinical samples were received from diabetic patients, out of 430, 72 (16.7%) P. aeruginosa were recovered. Multidrug resistance was exhibited by 34 isolates out of 72 P. aeruginosa strains. Out of 34 MDR strains, 10 (29.4%) were found ESBL producers by PCDDT, 9 (26.47%) by DDST while 10 (29.4%) were found positive by E test. Sensitivity, specificity and accuracy for PCDDT was found 90%, 95.8% and 94.1% respectively and ‘almost perfect agreement’ was observed with E test. Conclusion: Magnitude of multidrug resistant strains was found 47.22% among P. aeruginosa isolated from diabetic patients which is an alarming sign. The ESBLs were found in 29.4% isolates. So, screening of ESBLs with the use of simple test like PCDDT in Pseudomonas aeruginosa will direct us for treatment option of suitable antibiotic regimens in diabetic patients and to prevent the spread of drug resistant organisms in hospitals.

Analysis of the Genome of the Heavy Metal Resistant and Hydrocarbon-Degrading Rhizospheric Pseudomonas qingdaonensis ZCR6 Strain and Assessment of Its Plant-Growth-Promoting Traits.

The Pseudomonas qingdaonensis ZCR6 strain, isolated from the rhizosphere of Zea mays growing in soil co-contaminated with hydrocarbons and heavy metals, was investigated for its plant growth promotion, hydrocarbon degradation, and heavy metal resistance. In vitro bioassays confirmed all of the abovementioned properties. ZCR6 was able to produce indole acetic acid (IAA), siderophores, and ammonia, solubilized Ca3(PO4)2, and showed surface active properties and activity of cellulase and very high activity of 1-aminocyclopropane-1-carboxylic acid deaminase (297 nmol α-ketobutyrate mg−1 h−1). The strain degraded petroleum hydrocarbons (76.52% of the initial hydrocarbon content was degraded) and was resistant to Cd, Zn, and Cu (minimal inhibitory concentrations reached 5, 15, and 10 mM metal, respectively). The genome of the ZCR6 strain consisted of 5,507,067 bp, and a total of 5055 genes were annotated, of which 4943 were protein-coding sequences. Annotation revealed the presence of genes associated with nitrogen fixation, phosphate solubilization, sulfur metabolism, siderophore biosynthesis and uptake, synthesis of IAA, ethylene modulation, heavy metal resistance, exopolysaccharide biosynthesis, and organic compound degradation. Complete characteristics of the ZCR6 strain showed its potential multiway properties for enhancing the phytoremediation of co-contaminated soils. To our knowledge, this is the first analysis of the biotechnological potential of the species P. qingdaonensis.

1282. Ceftolozane/Tazobactam Use in Critically Ill Patients Receiving Intermittent or Continuous Renal Replacement Therapy

BackgroundOur hospital recommends ceftolozane/tazobactam (CT) as a broad-spectrum agent for treatment of Gram-negative bacilli in patients with a recent or current multidrug resistant (MDR) Pseudomonas infection. CT is utilized in patients who are on renal replacement therapy (RRT) yet little data exist on the efficacy in this population. Currently there are no FDA-approved dosing recommendations for patients on continuous veno-venous hemodialysis (CVVHD). The purpose of this study was to describe the indications, dosing and outcomes of patients on CT while receiving RRT.MethodsAll patients receiving CT from 2015-20 were included if on RRT, either CVVHD or intermittent hemodialysis (iHD). Clinical success was defined as the absence of pre-treatment signs/symptoms and/or no escalated antibiotic treatment within 48 hours of completing therapy. 30-day mortality was defined as death from any cause within 30 days of CT completion. Patients treated after 2019 approval of higher dosing for hospital-associated/ventilator-acquired pneumonia (HAP/VAP) were noted.Results17 patients received 24 courses of CT while on RRT, 9 (53%) were immunocompromised. All patients were treated in the ICU for an MDR Pseudomonas infection. As shown in table 1, the most common indications were 49% HAP/VAP, 17% complicated intra-abdominal (cIAI), or 17% urinary tract infections (cUTI). 4 (24%) patients had additional treatment courses of CT started empirically when infection was suspected. Median time to initiation for all courses was 2 days after obtaining cultures and median duration was 7 days. 12 patients were on CVVHD (median flow rate 2.5L/hr) and 7 were on iHD. 2 patients received iHD after CVVHD. Median dose while on CVVHD was 1500mg every 8 hours. The median dose on iHD was that approved by FDA for cIAI and cUTI: 750mg x1 followed by 150mg every 8 hours. Clinical success was achieved in 12 (71%) patients and 30-day mortality was 8 (47%). Table 1: Details on first courses of CT for patients on RRT *Denotes treatment after 2019 FDA approval of 3g q8h for treatment of HAP/VAP in patients with normal renal function **Flow rate: Medium 1.5-2L/hr; High: >2.5L/hr +NA denotes patient that had passed away and therefore additional C/T courses were not applicableConclusionThis case series provides real-world results of outcomes for critically ill patients on RRT treated with CT. Clinical success rates were similar to other published literature despite the severity of illness of this cohort, which is corroborated by the high 30 day, all-cause mortality. Ultimately, further evaluation of CT dosing in patients on RRT is warranted. Disclosures Laura A. Puzniak, PhD, Merck & Co., Inc. (Employee) Kelly Harris, PharmD, BCPS, Merck & Co. Inc (Employee) Trevor C. Van Schooneveld, MD, FACP, BioFire (Individual(s) Involved: Self): Consultant, Scientific Research Study Investigator; Insmed (Individual(s) Involved: Self): Scientific Research Study Investigator; Merck (Individual(s) Involved: Self): Scientific Research Study Investigator; Rebiotix (Individual(s) Involved: Self): Scientific Research Study Investigator Scott J. Bergman, PharmD, FCCP, FIDSA, BCPS, BCIDP, Merck & Co., Inc (Grant/Research Support) Scott J. Bergman, PharmD, FCCP, FIDSA, BCPS, BCIDP, Merck & Co., Inc (Individual(s) Involved: Self): Research Grant or Support

In Vitro Antimicrobial Activity of the Siderophore Cephalosporin Cefiderocol against Acinetobacter baumannii Strains Recovered from Clinical Samples.

Background: Cefiderocol is a siderophore cephalosporin that exhibits antimicrobial activity against most multi-drug resistant Gram-negative bacteria, including Enterobacterales, Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia. Methods: A total of 20 multidrug-resistant A. baumannii strains were isolated from 2020 to 2021, molecularly characterized and tested to assess the in vitro antibacterial activity of cefiderocol. Thirteen strains were carbapenem-hydrolysing oxacillinase OXA-23-like producers, while seven were non-OXA-23-like producers. Minimum inhibitory concentrations (MICs) were determined by broth microdilution, considered as the gold standard method. Disk diffusion test was also carried out using iron-depleted CAMHB plates for cefiderocol. Results: Cefiderocol MICs ranged from 0.5 to 1 mg/L for OXA-23-like non-producing A. baumannii strains and from 0.25 to >32 mg/L for OXA-23-like producers, using the broth microdilution method. Cefiderocol MIC90 was 8 mg/L. Diameter of inhibition zone of cefiderocol ranged from 18 to 25 mm for OXA-23-like non-producers and from 15 to 36 mm for OXA-23-like producers, using the diffusion disk method. A large variability and a low reproducibility were observed during the determination of diameter inhibition zone. Molecular characterization showed that all isolates presented the ISAba1 genetic element upstream the blaOXA-51. Among OXA-23-like non-producers, four were blaOXA-58 positive and two were negative for all the resistance determinants analyzed. Conclusions: Cefiderocol showed in vitro antimicrobial activity against both carbapenem-susceptible and non-susceptible A. baumannii strains, although some OXA-23-like producers were resistant. Further clinical studies are needed to consolidate the role of cefiderocol as an antibiotic against MDR A. baumannii.

A CASE OF RETAINED ORAL CARE SPONGE IN THE BRONCHUS CAUSING PNEUMONIA IN CHRONICALLY VENTILATED PATIENT

TOPIC: Lung Pathology TYPE: Medical Student/Resident Case Reports INTRODUCTION: Aspiration of foreign bodies is not uncommon and mostly accidental with the highest prevalence in young children [1]. Occurrence in adults is rare and usually as a result of diminished consciousness, sedation, trauma, and neuromuscular disorders. We present a case of a 70 year old patient receiving chronic mechanical ventilation who had multiple episodes of hypoxia due to a dislodged oral care sponge. CASE PRESENTATION: A 70 year-old bedbound male with chronic mechanical ventilation (via tracheostomy?) after traumatic brain injury, and recurrent pneumonia was admitted for pneumonia. On admission, respiratory cultures grew Carbapenem resistant Acinetobacter Bumanii and Pseudomonas Aeruginosa with negative urinalysis and blood cultures. Chest radiograph showed bilateral lower lobe opacities. He was treated with vancomycin, polymyxin B, and meropenem. However, his FiO2 fluctuated between 40% and 60% and despite being on antibiotics he was persistently febrile. He continued to have copious secretions requiring frequent suctioning without any new infiltrates on repeat chest radiograph. A Computer tomography (CT) of the chest was performed which showed a tubular structure extending from the right main bronchus to the bronchus intermedius (Image 1). Bronchoscopy was done and the object was found to be the head of an oral care sponge. After foreign body removal his respiratory status improved and fevers resolved. DISCUSSION: Oral care in mechanically ventilated patients has been studied extensively and there are many guidelines recommend to minimize ventilator associated pneumonia. Extreme care must be taken by providers as defective products or aggressive technique can result in fragments being dislodged into the oral cavity and can result in aspiration especially in patients with chronic tracheostomy. In patients with tracheostomy, diminished airway protective mechanisms and a deflated balloon can result in an increased risk of foreign body aspiration. Aspiration of a foreign body is a significant cause of morbidity as it can cause asphyxiation or trauma to the airway resulting in pneumothorax, bleeding, and infections [2]. In patients with diminished consciousness the signs of foreign body aspirations can be subtle such a mild cough, fevers, frequent infections, or increasing oxygen and they may not be able to provide a proper history. CONCLUSIONS: This case highlights the need for vigilance regarding potential complications from providing oral care in the elderly who have diminished ability to protect their airway. REFERENCE #1: 1. Ding G et al., Tracheobronchial foreign body aspiration in children: A retrospective single-center cross-sectional study. Medicine (Baltimore). 2020 May 29;99(22):e20480. REFERENCE #2: 2. Aissaoui, N. H. Salem, and A. Chadly, "Unusual foreign body aspiration as a cause of asphyxia in adults: an autopsy case report," The American Journal of Forensic Medicine and Pathology, vol. 33, no. 3, pp. 284–285, 2012. DISCLOSURES: No relevant relationships by Kabu Chawla, source=Web Response No relevant relationships by Varun tej Gonuguntla, source=Web Response Speaker/Speaker's Bureau relationship with pfizer Please note: $1001 - $5000 by Yizhak Kupfer, source=Admin input, value=Consulting fee No relevant relationships by Sharad Oli, source=Web Response No relevant relationships by kiran para, source=Web Response No relevant relationships by Ankur Sinha, source=Web Response

A CASE REPORT OF IBRUTINIB-INDUCED PNEUMONITIS

TOPIC: Lung Pathology TYPE: Medical Student/Resident Case Reports INTRODUCTION: Ibrutinib irreversibly inhibits Bruton's tyrosine kinase, an essential component of B-cell receptor signaling, leading to diminished proliferation and survival of malignant B-cells. Ibrutinib is used to treat leukemias and lymphomas, including chronic lymphocytic leukemia (CLL). Several complications are associated with ibrutinib, below describes a case of ibrutinib induced pneumonitis. CASE PRESENTATION: 64-year-old female recently diagnosed with CLL and started on ibrutinib therapy. Two months later, patient was admitted for progressive dyspnea and nonproductive cough. Initial work-up showed hypoxia, lymphocytic leukocytosis, negative COVID and respiratory viral pathogen panel (RVP). Computed tomography (CT) of chest showed new bilateral ground-glass opacities compared to CT scan three months earlier. She was initially treated with ceftriaxone and azithromycin. Patient had worsening respiratory status and required intubation on day four. Patient did not improve with several antibiotics and antifungals. But given history and borderline elevated beta-D-glucan, she underwent bronchoscopy due to concern for fungal infection. All studies including tuberculosis, histoplasma, aspergillus, coccidioides, blastomyces, pneumocystis jiroveci, fungal and bacterial cultures were negative. All antimicrobials were stopped. Patient had spontaneous pneumothoraxes on hospital day 13 and 15 requiring left needle decompression and bilateral chest tube placement. A sputum culture was repeated which grew few multi-drug resistant pseudomonas. She was treated with 7-day course of meropenem without improvement. Repeat workup showed bilateral ground-glass opacities, negative COVID, RVP, and bronchoscopy with negative fungal antigens, bacterial and fungal cultures. Given concern for ibrutinib induced pneumonitis, steroids were started with subsequent weaning from ventilator support to room air. DISCUSSION: Pneumonitis and pneumothorax are rare complications of ibrutinib therapy. The new ground-glass opacities, not present on imaging prior to starting ibrutinib, dyspnea and hypoxia, no prior lung disease, and no other new medications, is concerning for ibrutinib associated pneumonitis. Infection did not cause the opacities, both extensive infectious workups were unremarkable. The pseudomonas sputum culture was likely colonization from prolonged intubation, as she was afebrile, had stable leukocytosis, and treatment did not change respiratory status. Patient also had spontaneous pneumothoraces on lung protective ventilation. She has no history of pneumothorax, nor underlying condition that would lead to pneumothorax. In addition, oxygenation improved after starting steroids. She was weaned from ventilator support to room air, further supporting ibrutinib associated pneumonitis. CONCLUSIONS: Pneumonitis is a rare, notable complication of ibrutinib therapy. REFERENCE #1: Rai, K. R., MD, & Stilgenbauer, S., MD. (2021, January 07). Selection of Initial Therapy For Symptomatic or Advanced Chronic Lymphocytic Leukemia. Retrieved from https://www.uptodate.com/contents/selection-of-initial-therapy-for-symptomatic-or-advanced-chronic-lymphocytic-leukemia?search=ibrutinib pneumonitissIbrutinib-induced pneumonitis in patients with chronic lymphocytic leukemia. Blood 2016;127 (8): 1064–1067. doi: https://doi.org/10.1182/blood-2015-12-686873 DISCLOSURES: No relevant relationships by Tyler Cooper, source=Web Response No relevant relationships by Lauren Sesemann, source=Web Response

Bacteria from bovine clinical mastitis showed multiple drug resistance.

Mastitis, which often manifests as udder infection in dairy animals, is of great concern as it affects public health and results in heavy economic losses to the dairy industry. A hospital-based cross-sectional study was conducted to determine the cultivable bacterial species associated with bovine clinical mastitis and their resistance patterns towards different antimicrobials. The milk samples from cows suffering from clinical mastitis during monsoon season were investigated. The prevalence of clinical mastitis was significantly high in Holstein-Friesian crossbred cows, followed by in Jersey crossbred, Red Kandhari and Deoni. Significantly high prevalence was observed during 4th to 6th months of lactation. A total of 110 bacterial isolates belonging to 14 different genera were isolated and identified. Aminoglycosides and quinolones were found to be the most effective antibiotics. Vancomycin resistant penicillinase producing Gram positive bacteria were demonstrated. Gram negative bacteria resistant to extended spectrum β lactamases, cephalosporins, tetracyclines, vancomycin and chloramphenicol as well as vancomycin resistant enterococci, multiple drug resistant (MDR) gram negative rods, MDR Pseudomonas and MDR Acinetobacter were found. Widespread resistance of Streptococcus uberis towards cephalosporins was documented. Variable MDR patterns were recorded within a single species. MDR transfer from non-pathogens to emerging foodborne and established mastitis pathogens could be a potential problem to the dairy industry as well as to public health.

In vitro inhibition of multi-drug resistant Pseudomonas efflux pump by Xylopia aethiopica (Dunal) A. Rich

Global health is under constant threat due to antimicrobial drug resistance. Bacterial Infections caused by Pseudomonas aeruginosa are of importance because of their antibiotics resistance. This study aimed at evaluating the effects of extracts of Xylopia aethiopica (XA) on multidrug-resistant (MDR) Pseudomonas isolates. Fresh samples of XA leaf, stem bark and roots were collected from the botanical garden, University of Ibadan, Nigeria. Dried and pulverized samples were extracted with methanol and partitioned into n-hexane, dichloromethane and ethyl acetate. Phytochemical screening of the extracts was performed by standard methods. Antimicrobial activity and synergistic interaction were determined using microdilution and checkerboard broth dilution methods, respectively. The results revealed that crude methanol extracts of XA leaf, stem bark and root significantly (p<0.05) inhibited the growth of all tested MDR Pseudomonas isolates at 10 mg/mL. At 1 mg/mL, the ethyl acetate fraction of the leaf, and dichloromethane fraction of the roots produced clear zones of inhibition of 12 – 20 mm, and minimum inhibitory concentrations (MICs) of 1 µg/mL and 0.5 mg/mL, respectively. The modulation factor (MF) of ciprofloxacin, dichloromethane fraction of XA roots and ethyl acetate fraction of XA leaf were 4, 8, and 4 on MDR isolates E01006, OAU058 and P. aeruginosa ATCC 27853, respectively. In all tested isolates, but not E01006 and E01024, the fractional MICs of ciprofloxacin/ethylacetate fraction of XA leaf extract combination was not significantly different (p>0.05) compared with ciprofloxacin/verapamil combination. In conclusion, the root and leaf fractions Xylopia aethiopica that demonstrated antimicrobial activity against MDR P. aeruginosa and synergised with ciprofloxacin have the potential to rejuvenate the antimicrobial activity of ciprofloxacin in MDR P. aeruginosa.

Detection of Antibiotic Resistance Genes Among Multiple Drug Resistant Pseudomonas Aeruginosa Isolated from Clinical Sources in Selected Health Institutions in Kwara State.

Pseudomonas aeruginosa (P. aeruginosa) is a frequent nosocomial pathogen that causes severe diseases in many clinical and community settings. Strains of P. aeruginosa are associated with increased morbidity, mortality and healthcare costs. The rapid emergence of antimicrobial resistance among these strains is a public health crisis. Moreover, there is a paucity of data on the characterization of P. aeruginosa isolates from human clinical samples in Kwara State. The objectives of this study are to investigate the occurrence of metallo β-lactamase enzyme, multiple antibiotic resistant P. aeruginosa among clinical samples and detection of antibiotic resistance genes among them. Two hundred and thirty-five samples comprising of 145 males and 90 females human clinical specimens were collected aseptically from five selected health institutions within Kwara State, Nigeria. The samples were cultured immediately using standard microbiological procedures. Multiple drug resistance patterns of the micro-organisms to different antibiotics were determined using the Bauer Kirby disc diffusion technique. Metallo β-lactamase production was determined using E - test strip and the DNA samples of the multiple resistant P. aeruginosa strains were extracted and subjected to Polymerase Chain Reaction (PCR) for resistant genes determination. Data were subjected to descriptive statistics using Statistical Package for Social Sciences (SPSS) software. A total of 145 isolates were identified for P. aeruginosa from the clinical samples. Thirty were positive for metallo β-lactamase production; 11 (8%) males and 19 (13%) females. Absolute resistance to ceftazidime (100%), gentamicin (100%), ceftriaxone (100%) were observed while low resistance to ciprofloxacin (12.4%), piperacillin (6.9%) and imipenem (6.9%). All isolates were sensitive to colistin. The prevalence of various encoding genes blaVIM, , blaCTX-M and blaTEM were 34.4%, 46.7%, 16.7% and 37.7% respectively. This study has shown that there is a high occurrence of metallo β-lactamase enzyme producing and antibiotic-resistant strains of P. aeruginosa in clinical specimens from the studied area. Necessary measures must, therefore be implemented to stop the problems of this antibiotic resistance.

FIGHT AGAINST SUPERBUGS IN A BURN CENTRE: ARE WE DOING ENOUGH

Objective: To determine the superbug infection in a burn centre, its impact on mortality/morbidity and to review all preventive/therapeutic steps taken to fight this menace.
 Study Design: Retrospective cross sectional study.
 Place and Duration of Study: Department of Burns & Plastic Surgery, Army Burn Centre, Combined Military Hospital Kharian, from Oct 2018 to Sep 2019.
 Methodology: A detailed retrospective audit of departmental data was carried out. Parameters like direct admission vs transferred patient, percentage of burns (Total Burn Surface Area-TBSA%), records of all burns related deaths and all culture/sensitivity reports were analysed using SPSS-20. As a standard practice in our unit blood, tracheal secretions and pus culture specimens of all patients are collected at the time of admission and then periodically fresh samples are taken every week or earlier when-ever required.
 Results: Out of 515 patients, 283 (54.95%) were children under the age of 12 years. The overall survival rate improved by 13.43% as compared to last year. Out of 584 bacteriology reports 396 (67.81%) were positive and 188 (32.19%) were negative. On culture 508 organisms were isolated, majority of which were Carbapenem Resistant Pseudomonas, Acinetobacter, Enterobacteriaceae and Methicillin resistant staphylococcus aureus.
 Conclusion: Multi drug resistant superbug infection is a worldwide menace. The best clinical practices, strict contact isolation, enhanced environmental cleaning and judicious use of appropriate antibiotics are the main strategies in this war. Need for newer more effective antibiotics cannot be overemphasized.

Healthcare microenvironments define multidrug-resistant organism persistence.

Multidrug-resistant organisms (MDROs) colonizing the healthcare environment have been shown to contribute to risk for healthcare-associated infections (HAIs), with adverse effects on patient morbidity and mortality. We sought to determine how bacterial contamination and persistent MDRO colonization of the healthcare environment are related to the position of patients and wastewater sites. We performed a prospective cohort study, enrolling 51 hospital rooms at the time of admitting a patient with an eligible MDRO in the prior 30 days. We performed systematic sampling and MDRO culture of rooms, as well as 16S rRNA sequencing to define the environmental microbiome in a subset of samples. The probability of detecting resistant gram-negative organisms, including Enterobacterales, Acinetobacter spp, and Pseudomonas spp, increased with distance from the patient. In contrast, Clostridioides difficile and methicillin-resistant Staphylococcus aureus were more likely to be detected close to the patient. Resistant Pseudomonas spp and S. aureus were enriched in these hot spots despite broad deposition of 16S rRNA gene sequences assigned to the same genera, suggesting modifiable factors that permit the persistence of these MDROs. MDRO hot spots can be defined by distance from the patient and from wastewater reservoirs. Evaluating how MDROs are enriched relative to bacterial DNA deposition helps to identify healthcare micro-environments and suggests how targeted environmental cleaning or design approaches could prevent MDRO persistence and reduce infection risk.

THE SYNERGISTIC EFFECT OF GOLD NANOPARTICLE LOADED WITH CEFTAZIDIUM ANTIBIOTIC AGAINST MULTIDRUG ERSISTANCE PSEUDOMONAS AERUGINOSA

This study was aimed to evaluate the antimicrobial activity of gold nanoparticles that was synthesized by biological method using Aloe Vera extract. The Surface morphology of the synthesized gold nanoparticles was confirmed by Atomic force microscope (AFM) while the nature of functional groups present in gold nanoparticles was determined by FT-IR analysis. The antibacterial activity of gold nanoparticle was tested against multidrug resistance (MDR)pseudomonas aeruginosa, the results showed a significant effect against MDR isolates. Gold nanoparticle was loaded with ceftazidium antibiotic in order to improve the antibacterial activity and drug delivery efficiency. The synergistic effects of biosynthesize gold loaded with ceftazidium antibiotic at different concentration against MDR bacteria were also investigated. The result showed that ceftazidium-loaded nanoparticles have superior effectiveness compared to native ceftazidium against pseudomonas aeruginosa.

Characterisation of the Prevailing Multidrug Pseudomonas aeruginosa Strains from Surgical Wound Using 16S rRNA Sequencing Technique.

BackgroundPseudomonas aeruginosa (P. aeruginosa) is prevalent in hospital-acquired surgical wound infections. It exhibits both innate and acquired resistance to a broad range of antimicrobials and remains a principal problem in clinical practice.MethodsIn total, 284 sterile surgical wound swabs (142 each) were collected from two government hospitals: Central Hospital Benin (CHB) and University of Benin Teaching Hospital (UBTH) in Benin City, Nigeria. Pseudomonas spp. isolated from both hospitals were screened with eight different antibiotics by way of disk diffusion method. Polymerase chain reaction (PCR) amplification of 34 multiple drug-resistant isolates was carried out using genus-specific primer set on extracted genomic DNA for the identification of Pseudomonas spp. and substituent 16S rRNA sequencing to determine the prevailing strains in the two locations.ResultsSixty-two Pseudomonas spp. were isolated from the two locations (27 isolates from CHB and 35 isolates from the UBTH). Surgical wound infections screened with regularly used antibiotics revealed that 17 (62.9%) isolates from CHB and 20 (57.1%) isolates from UBTH were multiple drug resistant Pseudomonas spp. PCR identification using Pseudomonas spp. specific primer showed that 16 (94.1%) isolates from CHB and 18 (90%) isolates from UBTH were confirmed. The 16S DNA sequencing revealed that P. aeruginosa strain H25883 was dominant in both locations.ConclusionHigh antibiotic resistance among P. aeruginosa isolates was established in our study. PCR technique revealed a more reliable method of bacterial identification. H25883 strain of P. aeruginosa is the prevalent strain in both locations and it should be given attention in nosocomial surgical wound infections.

Bioremediation potential of biofilm forming multi-metal resistant marine bacterium Pseudomonas chengduensis PPSS-4 isolated from contaminated site of Paradip Port, Odisha

Bioremediation potential of biofilm forming multi-metal resistant marine bacterium Pseudomonas chengduensis PPSS-4 isolated from contaminated site of Paradip Port, Odisha

Molecular epidemiology of Pseudomonas aeruginosa isolated from lower respiratory tract of ICU patients.

Lower respiratory tract infections (LRTIs) caused by Pseudomonas aeruginosa are the most common infection among hospitalized patients, associated with increased levels of morbidity, mortality and attributable health care costs. Increased resistant Pseudomonas worldwide has been quite meaningful to patients, especially in intensive care unit (ICUs). Different species of Pseudomonas exhibit different genetic profile and varied drug resistance. The present study determines the molecular epidemiology through DNA fingerprinting method and drug resistance of P. aeruginosa isolated from patients with LTRIs admitted in ICU. A total of 79 P. aeruginosa isolated from patients with LRTIs admitted in ICU were characterized by Restriction Fragment Length Polymorphism (RFLP), Random Amplified Polymorphic DNA (RAPD) and Repetitive Extrapalindromic PCR (REP-PCR). Antibiotic resistance was determined by minimum inhibitory concentration (MIC) assay while MDR genes, viz, blaTEM, blaOXA, blaVIM, blaCTX-M-15 were detected by polymerase chain reaction (PCR). Of the 137 Pseudomonas sp isolated from ICU patients, 57.7% of the isolates were reported to be P. aeruginosa. The overall prevalence of P. aeruginosa among the all included patients was 34.5%. The RAPD analysis yielded 45 different patterns with 72 clusters with 57% to 100% similarity level. The RFLP analysis yielded 8 different patterns with 14 clusters with 76% to 100% similarity level. The REP PCR analysis yielded 37 different patterns with 65 clusters with 56% to 100% similarity level. There was no correlation among the different DNA patterns observed between the three different methods. Predominant of the isolates (46.8%) were resistant to amikacin. Of the 79 isolates, 60.8% were positive for blaTEM gene and 39.2% were positive for blaOXA gene. P. aeruginosa was predominantly isolated from patients with LRTIs admitted in ICU. The difference in the similarity level observed between the three DNA fingerprinting methods indicates that there is high inter-strain variability. The high genetic variability and resistance patterns indicates that we should continuously monitor the trend in the prevalence and antibiotic resistance of P. aeruginosa especially in patients with LRTIs admitted in ICU.

Antimicrobial Resistanceamong Intensive Care Unit Patients in A Tertiary Care Hospital of Bangladesh

Background: Antimicrobial resistance is a growing concern specially among the critically ill patients who are often treated by multiple antibiotics. But, the data regarding the pattern of antimicrobial resistance in this population are often insufficient.
 Objective: To observe the pattern of antimicrobial resistance among the patients admitted into the intensive care unit (ICU).
 Methodology: This prospective observational study was carried out in the ICU of a tertiary care hospital of Bangladesh over 6 months. Samples of blood, urine, tracheal aspirate, wound swab and pus were obtained from the patients, cultured and analyzed.
 Results: Among 100 subjects, the most common primary diagnoses were aspiration pneumonia (29%) and urinary tract infection (UTI) (24%). Out of 315 samples, microorganisms were isolated from 125 samples (39.68%). The most common sample yielding positive culture was tracheal aspirate (67.2%), and the most frequently isolated microorganisms were Pseudomonas spp. (35%), Escherichia coli (28%), Acinetobacterspp. (24%) andKlebsiellaspp. (18%). Acinetobacterspp., Pseudomonasspp. and Klebsiellaspp.were the commonest resistant organisms. Overall prevalence of resistance to antibiotics were: ceftriaxone 72%, ceftazidime 78.4%, ciprofloxacin 81.6%, gentamicin 84%, meropenem 49.6% andnetilmicin 39.2%. Meropenem was the most sensitive antibiotic against Klebsiellaspp.(66.67%) but Acinetobacterspp.was still resistant to meropenem and amikacin but sensitive to cotrimoxazole (66.67%). Multidrug resistant Pseudomonas, Acinetobacter and, Klebsiella species were found; piperacillin-tazobactam combination showed <40% resistance against them. No single antibiotic showed good efficacy against Acinetobacterspp.
 Conclusion: The prevalence of antibiotic resistance is high among the ICU patients, and the majority of the isolated organisms are resistant to conventional antibiotics.
 Bangladesh J Medicine January 2021; 32(1) : 5-11

110. Impact of Diagnostic and Antimicrobial Stewardship on Time-to-Appropriate Therapy and Clinical Outcomes in Multi-Drug Resistant Pseudomonas Infections

BackgroundTimely effective therapy in multi-drug resistant (MDR) Pseudomonas (PsA) infections has a direct impact on patient survival. We aimed to determine the impact of diagnostic and antimicrobial stewardship (AMS) on time-to-appropriate therapy (TAP) and clinical outcomes of patients with MDR PsA infections utilizing novel beta-lactam/beta-lactamase inhibitors (BL/BLIs).MethodsRetrospective cohort study of adult patients with MDR PsA infections at a 1,500-bed University-affiliated public hospital in Miami, Florida who received ≥72 hours of ceftazidime-avibactam (C/A) or ceftolozane-tazobactam (C/T). During the pre-intervention period (12/2017-12/2018), additional susceptibilities for C/A and C/T were performed upon providers’ request. In the post intervention period (01/2019 – 12/2019), we implemented automatic reflex algorithms (Figure 1) for faster identification and susceptibilities for MDR PsA, including carbapenemase producers. Results were communicated in real-time to the AMS team.Figure 1. Reflex Testing Algorithm for MDR Pseudomonas Isolates from Any Source ResultsSeventy-six patients were included; median age was 56 years (IQR 37.5–67.0), 40 (52.6%) were in an intensive care unit at time of culture collection; median APACHE II score was 20 (IQR 15.0 – 26.0). Three isolates were carbapenemase producers (VIM = 2; KPC = 1). The most common infections were pneumonia (56.6%) and bacteremia (18.4%). We found a significant decrease in median TAP (120.1 [IQR 82.5–164.6] vs 75.9 [IQR 51.3–101.7] hours, p = 0.003). Median time from culture collection to final susceptibility results was shorter in the post-intervention group (122.2 vs 90.5 hours; p < 0.001). Median length-of-stay after culture collection was numerically lower in the post-intervention group (26.0 [11.6–59.4] vs 19.7 [12.9–37.8] days; p = 0.33). Controlling for ICU admission, our intervention was not associated with decreased 30-day inpatient mortality (OR = 1.62, 95% CI 0.45–5.79).ConclusionOur study identified an improvement in TAP in MDR PsA infections with implementation of diagnostic and AMS initiatives. In an adequately powered study, our intervention could potentially impact patient survival through timely initiation of effective therapy with novel BL/BLIs.Disclosures All Authors: No reported disclosures

299. Paediatric Collaborative Network on Infections in Canada (PICNIC) Study of the Current Landscape of Gram Negative Bacteremias

BackgroundAntimicrobial resistance is a public health threat, invasive infection from multi-drug resistant gram-negative (MDRGN) pathogens is associated with significant morbidity and mortality. The incidence of MDRGN bacteremia in Canada is rising, and pediatric data is limited.MethodsThis retrospective chart review of paediatric patients with gram negative bacteremia in a multicenter PICNIC database (n=7 centers) from 2013 to 2017. MDRGN was defined as enterobacteriaceae that were resistant to third generation cephalosporins (including ESBL, CPE). Ethics approval was obtained at all sites, and data was entered into a secure REDCAP database, descriptive statistics are described herein.ResultsOf the 676 bacteremia patients in the database, 214 (31.7%) were gram negative pathogens. E. coli was the most frequent pathogen (59.8%, of which 22 of 128 were MDR), followed by Klebsiella (31.8%, of which 9 of 68 were MDR). Of the 31 MDRGNs, 19 were ESBL, 1 was a CPE, and 11 were nonspecific mechanisms of resistance. There were no multidrug resistant Pseudomonas, Stenotrophomonas, or Acinetobacter. The majority of patient were less than 3 months of age (59.3%) and were male (58.8%). The majority had an underlying comorbid condition; hematoncologic diagnosis accounting for 14.5%. Length of stay varied from 1 to 742 days (mean 72, standard deviation 88). 11% required admission to ICU, 10% required removal of a intravascular catheter, 7% required a change in ventilation status, 2% requiring procedural source control, and there was an 8% mortality rate. Treatment duration greater than 14 days occurred in 123 patients (61% of patients). ConclusionThis preliminary analysis of a multicenter review of pediatric gram negative bacteremias demonstrates a higher risk in neonates with comorbid conditions. A surprisingly prolonged treatment duration of greater than 14 days occurred in the majority of patients. Further analysis to assess factors associated with prolonged treatment durations, MDR infection, and complications is required. Gram negative bacteremia remains a significant cause of morbidity and mortality in pediatric patients.Disclosures All Authors: No reported disclosures

Prevalence of Multi-drug Resistant (mdr) Pseudomonas sp. Among Patients Attending in Tertiary Care Hospital, Dhaka city, Bangladesh

Prevalence of Multi-drug Resistant (mdr) Pseudomonas sp. Among Patients Attending in Tertiary Care Hospital, Dhaka city, Bangladesh