Phenotypic and genotypic study of carbapenem-resistant Pseudomonas aeruginosa strains isolated from hospitalized patients

Abstract Introduction: Nosocomial infections caused by Pseudomonas aeruginosa producing carbapenemases represent an important cause of morbidity and mortality among immunosuppressed patients. The aim of our study was to detect the production of metallo-carbapenemases (MBLs) by phenotypic methods and to detect the presence of the MBLs encoding genes (blaIMP and blaVIM) by PCR in P. aeruginosa strains isolated from hospitalized patients to the Regional Institute of Gastroenterology and Hepatology, Cluj-Napoca. Material and methods: Between September 2014-February 2015, we tested thirty-eight P. aeruginosa strains resistant to carbapenems according to CLSI 2014 breakpoints, determined by Vitek®2(BioMérieux),isolated from various clinical specimens. Phenotypic detection of the MBLs production was performed using the KPC/MBL Confirmation kit (ROSCO®) and the MBL Etest® IP/IPI (BioMérieux). We used the PCR method for detecting MBLs encoding genes: blaIMP, blaVIM. Results: The strains were obtained from surgery (55.3%), ICU (15.8%) and gastroenterology wards (28.9%), isolated from pus (25.8%), tracheal secretion (22.7%), bile (13.6%), sputum (10.6%), blood (10.6%), other secretions (16.7%). These strains were resistant to multiple classes of antibiotics. By ROSCO® method 28/38 strains (73.7%) were positive with imipenem ± dipicolinic acid (DPA) and 22/38 (57.9%) with meropenem ± DPA. Etest® waspositive for the 28/38 strains (73.7%). 11 strains (28.9%) were positive for KPC with the screening method. We identified: 6 blaIMP+ (15.8%), 2 (5.3%) blaVIM+ and 4 blaIMP+/blaVIM+ strains (10.5%). Conclusion: Both genes encoding MBL were found, alone or in combination. The increasing level of carbapenem resistance of these strains impose their routine testing to detect MBL.

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Molecular investigation of an outbreak associated with total parenteral nutrition contaminated with NDM-producing Leclercia adecarboxylata

BMC Infectious Diseases ◽

10.1186/s12879-021-05923-0 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Elvira Garza-González ◽

Paola Bocanegra-Ibarias ◽

Eduardo Rodríguez-Noriega ◽

Esteban González-Díaz ◽

Jesús Silva-Sanchez ◽

...

Keyword(s):

Comparative Genomics ◽

Carbapenem Resistance ◽

Clonal Diversity ◽

Molecular Characteristics ◽

Molecular Evidence ◽

Carbapenem Resistant ◽

Parental Nutrition ◽

Genes Encoding ◽

Main Lineage ◽

Encoding Genes

Abstract Background This study aimed to determine the epidemiological, microbiological, and molecular characteristics of an outbreak of carbapenem-resistant Leclercia adecarboxylata in three hospitals associated with the unintended use of contaminated total parental nutrition (TPN). Methods For 10 days, 25 patients who received intravenous TPN from the same batch of a formula developed sepsis and had blood cultures positive for L. adecarboxylata. Antimicrobial susceptibility and carbapenemase production were performed in 31 isolates, including one from an unopened bottle of TPN. Carbapenemase-encoding genes, extended-spectrum β-lactamase–encoding genes were screened by PCR, and plasmid profiles were determined. Horizontal transfer of carbapenem resistance was performed by solid mating. Clonal diversity was performed by pulsed-field gel electrophoresis. The resistome was explored by whole-genome sequencing on two selected strains, and comparative genomics was performed using Roary. Results All 31 isolates were resistant to aztreonam, cephalosporins, carbapenems, trimethoprim/sulfamethoxazole, and susceptible to gentamicin, tetracycline, and colistin. Lower susceptibility to levofloxacin (51.6%) and ciprofloxacin (22.6%) was observed. All the isolates were carbapenemase producers and positive for blaNDM-1, blaTEM-1B, and blaSHV-12 genes. One main lineage was detected (clone A, 83.9%; A1, 12.9%; A2, 3.2%). The blaNDM-1 gene is embedded in a Tn125-like element. Genome analysis showed genes encoding resistance for aminoglycosides, quinolones, trimethoprim, colistin, phenicols, and sulphonamides and the presence of IncFII (Yp), IncHI2, and IncHI2A incompatibility groups. Comparative genomics showed a major phylogenetic relationship among L. adecarboxylata I1 and USDA-ARS-USMARC-60222 genomes, followed by our two selected strains. Conclusion We present epidemiological, microbiological, and molecular evidence of an outbreak of carbapenem-resistant L. adecarboxylata in three hospitals in western Mexico associated with the use of contaminated TPN.

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Phenotypic prevalence of resistance to carbapenems, colistin and genes encoding carbapenemase in Pseudomonas aeruginosa

MedPharmRes ◽

10.32895/ump.mpr.5.1.4 ◽

2021 ◽

Vol 5 (1) ◽

pp. 18-22

Author(s):

Mai Thi Thanh Nguyen ◽

Chuong Van Le ◽

Phuong Mai Doan ◽

Chinh Van Nguyen ◽

Huy Quang Vu

Keyword(s):

Pseudomonas Aeruginosa ◽

Effective Treatment ◽

Resistance Genes ◽

Real Time Pcr ◽

Carbapenem Resistance ◽

Good Effect ◽

Colistin Resistance ◽

Carbapenem Resistant ◽

Genes Encoding

Introduction: The production of carbapenem enzyme is one of the most frequent mechanisms reported in cabapenem resistant Pseudomonas aeruginosa. Besides, a growing number of mobile colistin resistance (MCR) genes are threatening the renewed interest of colistin as a "last-resort" against carbapenem-resistant pathogens. Therefore, the detection of carbapenem-resistant and colistin-resistant phenotypes as well as preventing transmission of multi-resistant P. aeruginosa strains with genes coding for carbapenemase is extremely necessary. Material and methods: Among 159 P. aeruginosa strains were collected 46 isolates, which is resistant or intermediated to meropenem. Modified carbapenem inactivation (mCIM) and colistin broth disk elution (CBDE) methods were used to identify carbapenemase-producing strains and colistin resistance. In addition, a multiplex real-time PCR technique was applied to investigate the frequency of emergence of carbapenem resistance genes. Results: The results revealed that 25 strains (54.3%) were positive with mCIM test and none of them resistant to colistin by CBDE method. Number of strains carrying a gene blaIMP: 4 strains (16%), blaNDM: 2 strains (8%). Strains are carrying two genes: blaIMP + blaNDM: 10 strains (40%), blaVIM + blaNDM: 1 strain (4%), blaNDM + blaOXA-48: 1 strain (4%) and are carrying three genes blaIMP + blaNDM + blaOXA-48: 6 strains (24%), blaKPC + blaIMP + blaNDM: 1 strain (4%). Conclusions: All mCIM positive P. aeruginosa were contained carbapenemase genes. Colistin still reserved a good effect to combine with other antibiotics in multi-resistant treatment. Hence, the classification of genes can help clinicians selected appropriate antibiotics so that more effective treatment for patients.

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Prevalence of the Genes Associated with Biofilm and Toxins Synthesis amongst the Pseudomonas aeruginosa Clinical Strains

Antibiotics ◽

10.3390/antibiotics10030241 ◽

2021 ◽

Vol 10 (3) ◽

pp. 241

Author(s):

Tomasz Bogiel ◽

Dagmara Depka ◽

Mateusz Rzepka ◽

Joanna Kwiecińska-Piróg ◽

Eugenia Gospodarek-Komkowska

Keyword(s):

Pseudomonas Aeruginosa ◽

Virulence Genes ◽

Carbapenem Resistance ◽

Genotype Distribution ◽

Isolation Frequency ◽

Carbapenem Resistant ◽

Pila Gene ◽

Different Origins ◽

Encoding Genes ◽

Virulence Factor Genes

Pseudomonas aeruginosa is one of the most commonly isolated bacteria from clinical specimens, with an increasing isolation frequency in nosocomial outbreaks. The hypothesis tested was whether carbapenem-resistant P. aeruginosa strains display an altered carriage of the virulence factor genes, depending on the type of carbapenem resistance. The aim of the study was to investigate, by PCR, the frequency of 10 chosen virulence factors genes (phzM, phzS, exoT, exoY, exoU, toxA, exoS, algD, pilA and pilB) and the genotype distribution in 107 non-duplicated carbapenem-resistant P. aeruginosa isolates. P. aeruginosa genes involved in phenazine dyes and exoenzyme T synthesis were noted with the highest frequency (100%). Fimbriae-encoding genes were detected with the lowest incidence: 15.9% and 4.7% for pilin A and B, respectively. The differences observed between the exoS gene prevalence amongst the carbapenemase-positive and the carbapenemase-negative strains and the pilA gene prevalence amongst the strains of different origins were statistically significant. Virulence genes’ prevalence and the genotype distribution vary amongst P. aeruginosa strains resistant to carbapenems, especially in terms of their carbapenemase synthesis ability and the strain origin.

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Carbapenem resistance in non-fermentative bacterial species and in Enterobacteriaceae isolates from hospitalized patients in different health-care settings

Medicine and Pharmacy Reports ◽

10.15386/cjmed-282 ◽

2014 ◽

Vol 87 (4) ◽

pp. 235-241

Author(s):

Mihaela Ileana Ionescu ◽

Dan Stefan Neagoe ◽

Claudia Chiorean ◽

Loredana Dumitras ◽

Aurelia Rus

Keyword(s):

Health Care ◽

Pseudomonas Aeruginosa ◽

Intensive Care ◽

Intensive Care Units ◽

Carbapenem Resistance ◽

Hospitalized Patients ◽

Health Care Settings ◽

Carbapenem Resistant ◽

Acinetobacter Spp ◽

Resistant Strains

Aim. Carbapenem-resistant strains have been increasingly reported over the last few years. In this study we used laboratory records to determine the occurrence of carbapenem-resistant strains from hospitalized patients with emphasis on the comparative analysis of the incidence in various health-care settings. Materials and methods. From January 2012 to November 2012 and from May 2013 to November 2013, we evaluated 566 strains (Acinetobacter spp., Pseudomonas aeruginosa, Escherichia coli, and Klebsiella spp.). All isolates were tested and analyzed according to their antibiotic resistance phenotypic pattern. Laboratory results were correlated with data regarding admission in different clinical wards.Results. Among 566 isolates, 191 carbapenem-resistant or carbapenem-intermediate strains (33.74%) were detected. Non-fermentative species were the most prevalent carbapenem-resistant organisms, 80.62% of 191 carbapenem-resistant or carbapenem-intermediate strains isolated were Acinetobacter spp., and 17.27% of 191 were Pseudomonas aeruginosa. Apart from that, only 4 (2.09%) carbapenem-resistant Enterobacteriaceae (CRE) strains were identified. We identified 59.30% of 172 strains isolated from patients hospitalized in anesthesia and intensive care units non-susceptible to carbapenems. The main mechanism associated with carbapenem resistance could be the production of carbapenemase in combination with impermeability.Conclusions. Our study demonstrates that infections with carbapenem-resistant strains are correlated with hospitalization in intensive care units. Our data showed a predominant carbapenem-resistant Acinetobacter spp. strain in intensive care units.

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Prevalence of carbapenemase production in Pseudomonas aeruginosa isolates causing clinical infections in Lagos University Teaching Hospital, Nigeria

African Journal of Clinical and Experimental Microbiology ◽

10.4314/ajcem.v22i4.10 ◽

2021 ◽

Vol 22 (4) ◽

pp. 498-503

Author(s):

A.O. Ettu ◽

B.A. Oladapo ◽

O.O. Oduyebo

Keyword(s):

Pseudomonas Aeruginosa ◽

Teaching Hospital ◽

Dipicolinic Acid ◽

Phenylboronic Acid ◽

Carbapenem Resistance ◽

Clinical Isolates ◽

University Teaching ◽

Diffusion Method ◽

Carbapenem Resistant ◽

Mueller Hinton

Background: Pseudomonas aeruginosa has been highly associated with carbapenem resistance in which carbapenemases has been suggested to be a major contributory factor. Hence the objective of this study was to phenotypically detect KPC-type carbapenemase, metallo-β-lactamase and OXA-48 carbapenemase production in clinical isolates of P. aeruginosa in Lagos University Teaching Hospital (LUTH), NigeriaMethodology: One hundred and seventy-one P. aeruginosa isolates consecutively recovered from clinical specimens of patients with infections at the Medical Microbiology and Parasitology laboratory of the hospital were identified using MicrobactTM 24E kit. Preliminary screening for carbapenem resistance was determined by the disc diffusion method on Mueller-Hinton agar using single discs of meropenem and imipenem. Phenotypic detection of carbapenemase production among carbapenem-resistant isolates was performed by the combination disc test of meropenem-phenylboronic acid (MRPBO) and meropenem-dipicolinic acid (MRPDP) as recommended by EUCAST 2013 guideline. Results: Out of the 171 P. aeruginosa isolates, 35 (20.5%) were carbapenem non-susceptible (resistant) while carbapenemase production was detected in 27 (77.1%) of these carbapenem resistant isolates, and no enzyme was detected in 8 (22.9%). Of the 27 carbapenemase producing isolates, 22 (81.5%) produced MBL, 1 (3.7%) produced KPC, while 4 (14.8%) produced both KPC and MBL enzymes. Conclusion: This study revealed that carbapenem resistance among P. aeruginosa clinical isolates in our institution is gradually increasing. The mechanism for this rise is associated with carbapenemases, with MBL being the major carbapenemase involved. There is the need to ensure strict compliance with the LUTH infection control guidelines in order to check the rising incidence of infection caused by carbapenem resistant P. aeruginosa. French title: Prévalence de la production de carbapénémases dans les isolats de Pseudomonas aeruginosa causant des infections cliniques à l'hôpital universitaire de Lagos, Nigéria Contexte: Pseudomonas aeruginosa a été fortement associé à la résistance aux carbapénèmes dans laquelle les carbapénèmases ont été suggérées comme étant un facteur contributif majeur. Par conséquent, l'objectif de cette étude était de détecter phénotypiquement la production de carbapénémase de type KPC, de métallo-β-lactamase et de carbapénémase OXA-48 dans des isolats cliniques de P. aeruginosa au Lagos University Teaching Hospital (LUTH), Nigeria. Méthodologie: Cent soixante et onze isolats de P. aeruginosa récupérés consécutivement à partir d'échantillons cliniques de patients infectés au laboratoire de microbiologie médicale et de parasitologie de l'hôpital ont été identifiés à l'aide du kit MicrobactTM 24E. Le dépistage préliminaire de la résistance aux carbapénèmes a été déterminé par la méthode de diffusion sur disque sur gélose Mueller-Hinton en utilisant des disques uniques de méropénème et d'imipénème. La détection phénotypique de la production de carbapénèmes parmi les isolats résistants aux carbapénèmes a été réalisée par le test de disque combiné d'acide méropénème-phénylboronique (MRPBO) et d'acide méropénème-dipicolinique (MRPDP) tel que recommandé par la directive EUCAST 2013. Résultats: Sur les 171 isolats de P. aeruginosa, 35 (20,5%) étaient des carbapénèmes non sensibles (résistants) tandis que la production de carbapénèmes a été détectée dans 27 (77,1%) de ces isolats résistants aux carbapénèmes, et aucune enzyme n'a été détectée dans 8 (22,9%). Sur les 27 isolats producteurs de carbapénémases, 22 (81,5%) produisaient des MBL, 1 (3,7%) produisaient des KPC, tandis que 4 (14,8%) produisaient à la fois des enzymes KPC et MBL. Conclusion: Cette étude a révélé que la résistance aux carbapénèmes parmi les isolats cliniques de P. aeruginosa dans notre institution augmente progressivement. Le mécanisme de cette augmentation est associé aux carbapénémases, la MBL étant la principale carbapénémase impliquée. Il est nécessaire de garantir le strict respect des directives de contrôle des infections LUTH afin de contrôler l'incidence croissante des infections causées par P. aeruginosa résistant aux carbapénèmes.

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Mobile Carbapenemase Genes in Pseudomonas aeruginosa

Frontiers in Microbiology ◽

10.3389/fmicb.2021.614058 ◽

2021 ◽

Vol 12 ◽

Author(s):

Eun-Jeong Yoon ◽

Seok Hoon Jeong

Keyword(s):

Pseudomonas Aeruginosa ◽

Carbapenem Resistance ◽

Mobile Genetic Elements ◽

Clinical Settings ◽

Genetic Elements ◽

Integrative And Conjugative Elements ◽

Carbapenem Resistant ◽

Resistance Rates ◽

Lactamase Gene ◽

Encoding Genes

Carbapenem-resistantPseudomonas aeruginosais one of the major concerns in clinical settings impelling a great challenge to antimicrobial therapy for patients with infections caused by the pathogen. While membrane permeability, together with derepression of the intrinsic beta-lactamase gene, is the global prevailing mechanism of carbapenem resistance inP. aeruginosa, the acquired genes for carbapenemases need special attention because horizontal gene transfer through mobile genetic elements, such as integrons, transposons, plasmids, and integrative and conjugative elements, could accelerate the dissemination of the carbapenem-resistantP. aeruginosa. This review aimed to illustrate epidemiologically the carbapenem resistance inP. aeruginosa, including the resistance rates worldwide and the carbapenemase-encoding genes along with the mobile genetic elements responsible for the horizontal dissemination of the drug resistance determinants. Moreover, the modular mobile elements including the carbapenemase-encoding gene, also known as theP. aeruginosaresistance islands, are scrutinized mostly for their structures.

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Carbapenem-resistant Pseudomonas aeruginosa originating from farm animals and people in Egypt

Journal of Veterinary Research ◽

10.2478/jvetres-2019-0049 ◽

2019 ◽

Vol 63 (3) ◽

pp. 333-337 ◽

Cited By ~ 3

Author(s):

Esraa A. Elshafiee ◽

Sara M. Nader ◽

Sohad M. Dorgham ◽

Dalia A. Hamza

Keyword(s):

Health Care ◽

Pseudomonas Aeruginosa ◽

Phylogenetic Analysis ◽

Drinking Water ◽

Carbapenem Resistance ◽

Farm Animals ◽

Contaminated Water ◽

Carbapenem Resistant ◽

Health Care Associated Infections ◽

Encoding Genes

Abstract Introduction Carbapenem-resistant Pseudomonas aeruginosa (CRPA) has become the leading cause of health care-associated infections. Treatment is difficult due to the lack of an effective antimicrobial therapy, and mortality is high. This study investigated the occurrence of CRPA in farm animals (buffaloes and cattle), livestock drinking water, and humans in Egypt. Material and Methods A total of 180 samples were examined: 50 faecal each from buffaloes and cattle, 30 of livestock drinking water, and 50 stool from humans. The samples were cultured on cetrimide agar and the plates were incubated aerobically at 37°C for 24 h. The isolates were examined for the presence of the blaKPC, blaOXA-48, and blaNDM carbapenemase-encoding genes using PCR and investigated for the exotoxin A (toxA) gene. The toxA gene from carbapenem- group resistant isolates was phylogenetically analysed. Results P. aeruginosa was isolated from buffaloes, cattle, drinking water, and humans, with occurrences of 40%, 34%, 10%, and 20%, respectively. Carbapenem resistance genes were found in 60%, 59%, 67%, and 70% in buffalo, cattle, water and human samples, respectively. The toxA gene was detected in 80% of samples. The phylogenetic analysis showed that cattle and water sequences were in one cluster and more related to each other than to human isolates. Conclusion Occurrence of CRPA among farm animals, drinking water, and humans was high, reflecting the environmental origin of P. aeruginosa and highlighting contaminated water as a potential transmitter of CRPA to livestock and next to humans.

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Prevalence of metallo-β-lactamase genes among Pseudomonas aeruginosa isolated from various clinical samples in China

Journal of Laboratory Medicine ◽

10.1515/labmed-2019-0162 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Wei Wang ◽

Xiaoya Wang

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibiotic Susceptibility ◽

Ethylenediaminetetraacetic Acid ◽

Carbapenem Resistance ◽

Opportunistic Pathogen ◽

Detection Methods ◽

Clinical Samples ◽

Routine Practice ◽

Carbapenem Resistant ◽

High Prevalence

AbstractBackgroundPseudomonas aeruginosa is an opportunistic pathogen which is associated with nosocomial infections and causes various diseases including urinary tract infection, pneumonia, soft-tissue infection and sepsis. The emergence of P. aeruginosa-acquired metallo-β-lactamase (MBL) is most worrisome and poses a serious threat during treatment and infection control. The objective of this study was to identify antibiotic susceptibility, phenotypic detection of MBL production and to determine the prevalence of MBL genes in carbapenem-resistant P. aeruginosa isolated from different clinical samples.MethodsA total of 329 non-duplicate P. aeruginosa isolated from various clinical samples from two hospitals in China between September 2017 and March 2019 were included in this study. Phenotypic detection of MBL was performed by the combined detection method using imipenem and imipenem-ethylenediaminetetraacetic acid (EDTA) discs. MBL-encoding genes including blaVIM-1, blaVIM-2, blaIMP-1, blaIMP-2, blaSPM-1, blaSIM, blaNDM-1 and blaGIM were detected by polymerase chain reaction (PCR).ResultsOf the 329 P. aeruginosa, majority of the isolates were resistant to imipenem (77.5%) followed by meropenem (64.7%). Of the 270 P. aeruginosa isolates tested, 149 (55.2%) isolates were found to be positive for MBL detection. Of the different samples, 57.8% (n = 26) of P. aeruginosa isolated from blood were found to be positive for MBL production. Of the various MBL genes, blaIMP-1 (28.2%) was the most predominant gene detected followed by blaVIM-2 (18.8%), blaVIM-1 (16.1%), blaNDM-1 (9.4%), blaIMP-2 (6.7%), blaSIM (6.0%), blaSPM-1 (4.0%) and blaGIM (1.3%) genes.ConclusionsThe high resistance of P. aeruginosa toward imipenem and meropenem and the high prevalence of blaIMP-1 and blaVIM-2 set the alarm on the increasing, perhaps the increased, carbapenem resistance. In addition to routine antibiotic susceptibility testings, our results emphasize the importance of both the phenotypic and genotypic MBL detection methods in routine practice for early detection of carbapenem resistance and to prevent further dissemination of this resistant pathogen.

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Molecular characterization of clinical carbapenem-resistant Enterobacterales from Qatar

European Journal of Clinical Microbiology & Infectious Diseases ◽

10.1007/s10096-021-04185-7 ◽

2021 ◽

Author(s):

Fatma Ben Abid ◽

Clement K. M. Tsui ◽

Yohei Doi ◽

Anand Deshmukh ◽

Christi L. McElheny ◽

...

Keyword(s):

Common Species ◽

Clinical Samples ◽

Whole Genome ◽

E Coli ◽

Carbapenem Resistant ◽

Genes Encoding ◽

Encoding Genes ◽

Sequence Types ◽

Common Sequence

AbstractOne hundred forty-nine carbapenem-resistant Enterobacterales from clinical samples obtained between April 2014 and November 2017 were subjected to whole genome sequencing and multi-locus sequence typing. Klebsiella pneumoniae (81, 54.4%) and Escherichia coli (38, 25.5%) were the most common species. Genes encoding metallo-β-lactamases were detected in 68 (45.8%) isolates, and OXA-48-like enzymes in 60 (40.3%). blaNDM-1 (45; 30.2%) and blaOXA-48 (29; 19.5%) were the most frequent. KPC-encoding genes were identified in 5 (3.6%) isolates. Most common sequence types were E. coli ST410 (8; 21.1%) and ST38 (7; 18.4%), and K. pneumoniae ST147 (13; 16%) and ST231 (7; 8.6%).

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834. Clinical Outcomes with Carbapenem-Resistant Pseudomonas aeruginosa that Retain Susceptibility to Traditional Antipseudomonal β-lactams: Atlanta, 2016-2018

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.1023 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S457-S458

Author(s):

Jessica Howard-Anderson ◽

Chris W Bower ◽

Gillian Smith ◽

Sarah W Satola ◽

Jesse T Jacob

Keyword(s):

Pseudomonas Aeruginosa ◽

Research Training ◽

Multivariable Analysis ◽

Care Facility ◽

Hospitalized Patients ◽

First Episode ◽

Common Source ◽

Unexpected Finding ◽

Term Care ◽

Carbapenem Resistant

Abstract Background Carbapenem-resistant Pseudomonas aeruginosa (CRPA) often results from multiple mechanisms, creating unique phenotypic patterns of resistance including retaining susceptibility to traditional antipseudomonal β-lactams: cefepime (FEP), ceftazidime (CAZ) and piperacillin-tazobactam (TZP). Outcomes of patients with CRPA susceptible to FEP, CAZ and TZP are unclear. Methods The Georgia Emerging Infections Programed performs active, population-based surveillance for CRPA (minimum inhibitory concentration [MIC] ≥ 8 µg/mL for doripenem, imipenem or meropenem) isolated from sterile sites, urine, lower respiratory tracts and wounds in metropolitan Atlanta. We created a retrospective cohort of adults without cystic fibrosis with their first episode of CRPA while hospitalized or hospitalized within 1 week, from 8/2016 – 7/2018. We compared patients with CRPA that remained susceptible to FEP, CAZ and TZP (“susceptible CRPA”) to those that were not (“resistant CRPA”) including multivariable logistic regression for 30-day mortality. Results Among 643 patients, 638 had susceptibility results available for FEP, CAZ or TZP. 60% were male, median age was 65 years, and median Charlson comorbidity index was 2 (Table 1). Most (66%) resided in a hospital or long-term care facility 4 days prior to culture. The most common source was urine (38%). Non-susceptibility to multiple antibiotic classes was common: 523 (81%) for 3 classes and 214 (33%) for 5 classes (Table 2). 220 (34%) patients had susceptible CRPA and compared to patients with resistant CRPA, were more likely to have lived in a private residence, have a community-associated infection, and less likely to be in the ICU previously (Table 1). Patients with susceptible CRPA had a similar crude 30-day mortality (16% vs 12%, p = 0.15) to those with resistant CRPA, but in a multivariable analysis had an increased 30-day mortality (OR 1.9; 95% CI 1.1–3.2). Table 1 (Part 1/2): Characteristics and outcomes of hospitalized patients with carbapenem-resistant Pseudomonas aeruginosa (CRPA) in metropolitan Atlanta, stratified by antipseudomonal β-lactam susceptibility Table 1 (Part 2/2): Characteristics and outcomes of hospitalized patients with carbapenem-resistant Pseudomonas aeruginosa (CRPA) in metropolitan Atlanta, stratified by antipseudomonal β-lactam susceptibility Table 2: Antibacterial susceptibility results for hospitalized patients with carbapenem-resistant Pseudomonas aeruginosa in metropolitan Atlanta Conclusion Over 1/3 of hospitalized patients with CRPA retained susceptibility to other antipseudomonal β-lactams, but had an increased mortality compared to CRPA resistant to other β-lactams. Further research into mechanisms of resistance or antibiotics received might help explain this unexpected finding. Disclosures Jessica Howard-Anderson, MD, Antibacterial Resistance Leadership Group (ARLG) (Other Financial or Material Support, The ARLG fellowship provides salary support for ID fellowship and mentored research training)

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