Mirabilis Isolates Research Articles

Proteus mirabilis – analysis of a concealed source of carbapenemases and development of a diagnostic algorithm for detection

ObjectivesTo analyse carbapenemases in Proteus mirabilis and assess the performance of carbapenemase detection assays. MethodsEighty-one clinical P. mirabilis isolates with high-level resistance at least to ampicillin (>32 mg/L) or previous detection of carbapenemases were selected and investigated by three susceptibility testing methods (microdilution, automated susceptibility testing, and disk diffusion), six phenotypic carbapenemase assays (CARBA NP, modified carbapenemase inactivation method [CIM], modified zinc-supplemented CIM, simplified CIM, faropenem, and carbapenem-containing agar), two immunochromatographic assays, and whole-genome sequencing. ResultsCarbapenemases were detected in 43 of 81 isolates (OXA-48-like [n = 13]; OXA-23 [n = 12]; OXA-58 [n = 12]; New Delhi metallo-β-lactamase (NDM) [n = 2]; Verona integron–encoded metallo-β-lactamase (VIM) [n = 2]; Imipenemase (IMP) [n = 1]; Klebsiella pneumoniae carbapenemase (KPC) [n = 1]). Carbapenemase-producing Proteus were frequently susceptible to ertapenem (26/43; 60%), meropenem (28/43; 65%), ceftazidime (33/43; 77%), and some even to piperacillin-tazobactam (9/43; 21%). Sensitivity/specificity of phenotypic tests were 30% (CI: 17–46%)/89% (CI: 75–97%) for CARBA NP, 74% (CI: 60–85%)/82% (CI: 67–91%) for faropenem, 91% (CI: 78–97%)/82% (CI: 66–92%) for simplified CIM, and 93% (CI: 81–99%)/100% (CI: 91–100%) for modified zinc-supplemented CIM. An algorithm for improved detection was developed, which demonstrated sensitivity/specificity of 100% (CI: 92–100%)/100% (CI: 91–100%) on the 81 isolates, and 100% (CI: 29–100%)/100% (CI: 96–100%) in a prospective analysis of additional 91 isolates. Interestingly, several OXA-23-producing isolates belonged to the same clonal lineage reported previously from France. DiscussionCurrent susceptibility testing methods and phenotypic tests frequently fail to detect carbapenemases in P. mirabilis, which could result in inadequate antibiotic treatment. In addition, the non-inclusion of blaOXA-23/OXA-58 in many molecular carbapenemase assays further impedes their detection. Therefore, the prevalence of carbapenemases in P. mirabilis is likely underestimated. With the herein proposed algorithm, carbapenemase-producing Proteus can be easily identified.

Genomes comparison of two Proteus mirabilis clones showing varied swarming ability

BackgroundProteus mirabilis is a Gram-negative bacteria most noted for its involvement with catheter-associated urinary tract infections. It is also known for its multicellular migration over solid surfaces, referred to as ‘swarming motility’. Here we analyzed the genomic sequences of two P. mirabilis isolates, designated K38 and K39, which exhibit varied swarming ability.Methods and resultsThe isolates genomes were sequenced using Illumina NextSeq sequencer, resulting in about 3.94 Mbp, with a GC content of 38.6%, genomes. Genomes were subjected for in silico comparative investigation. We revealed that, despite a difference in swarming motility, the isolates showed high genomic relatedness (up to 100% ANI similarity), suggesting that one of the isolates probably originated from the other.ConclusionsThe genomic sequences will allow us to investigate the mechanism driving this intriguing phenotypic heterogeneity between closely related P. mirabilis isolates. Phenotypic heterogeneity is an adaptive strategy of bacterial cells to several environmental pressures. It is also an important factor related to their pathogenesis. Therefore, the availability of these genomic sequences will facilitate studies that focus on the host–pathogen interactions during catheter-associated urinary tract infections.

Complete Genome Sequence of the Extensively Drug-Resistant Extended-Spectrum β-Lactamase-Producing Proteus mirabilis Isolate HK294, Obtained from Poultry Feces in Hong Kong.

Here, we report the complete genome sequence of Proteus mirabilis isolate HK294, recovered from pooled poultry feces in Hong Kong in 2022. The chromosome contained 32 antimicrobial resistance genes, including the extended-spectrum β-lactamases blaCTX-M-65 and blaCTX-M-3. Almost all resistance genes were part of either an integrative conjugative element or a Tn7-like transposon.

Virulence-related factors and antimicrobial resistance in Proteus mirabilis isolated from domestic and stray dogs.

Proteus mirabilis is a multi-host pathogen that causes diseases of varying severity in a wide range of mammals, including humans. Proteus mirabilis is resistant to multiple antibiotics and has acquired the ability to produce expanded spectrum of β-lactamases, leading to serious public health problems. However, the available information on P. mirabilis isolated from feces of dogs, is still poorly understood, as is the correlation between its virulence-associated genes (VAGs) and antibiotic resistance genes (ARGs). In this study, we isolated 75 strains of P. mirabilis from 241 samples, and investigated the swarming motility, biofilm formation, antimicrobial resistance (AMR), distribution of VAGs and ARGs, as well as the presence of class 1, 2, and 3 integrons in these isolates. Our findings suggest a high prevalence of intensive swarming motility and strong biofilm formation ability among P. mirabilis isolates. Isolates were primarily resistant to cefazolin (70.67%) and imipenem (70.67%). These isolates were found to carry ureC, FliL, ireA, zapA, ptA, hpmA, hpmB, pmfA, rsbA, mrpA, and ucaA with varying prevalence levels of 100.00, 100.00, 100.00, 98.67, 98.67, 90.67, 90.67, 90.67, 90.67, 89.33, and 70.67%, respectively. Additionally, the isolates were found to carry aac(6')-Ib, qnrD, floR, blaCTX-M, blaCTX-M-2, blaOXA-1, blaTEM, tetA, tetB and tetM with varying prevalence levels of 38.67, 32.00, 25.33, 17.33, 16.00, 10.67, 5.33, 2.67, 1.33, and 1.33%, respectively. Among 40 MDR strains, 14 (35.00%) were found to carry class 1 integrons, 12 (30.00%) strains carried class 2 integrons, while no class 3 integrons was detected. There was a significant positive correlation between the class 1 integrons and three ARGs: blaTEM, blaCTX-M, and blaCTX-M-2. This study revealed that P. mirabilis strains isolated from domestic dogs exhibited a higher prevalence of MDR, and carried fewer VAGs but more ARGs compared to those isolated from stay dogs. Furthermore, a negative correlation was observed between VAGs and ARGs. Given the increasing antimicrobial resistance of P. mirabilis, veterinarians should adopt a prudent approach towards antibiotics administration in dogs to mitigate the emergence and dissemination of MDR strains that pose a potential threat to public health.

Genotypic characterization of a Proteus mirabilis strain harboring blaKPC-2 on the IncN plasmid isolated from a patient with bloodstream infection in China

BackgroundCarbapenemase is the predominant enzyme in the mechanism leading to Enterobacterales resistance to carbapenems, and the rapid spread of the blaKPC gene is a major public health concern. Here, we describe a carbapenem-resistant Proteus mirabilis strain XH983, which harbored a blaKPC-2-producing IncN plasmid, isolated from a bloodstream infection. MethodsWhole-genome sequencing and bioinformatics analysis were performed to assess the genetic environment of P. mirabilis XH983. Conjugation and transfer experiments were performed and the corresponding strains were confirmed by antimicrobial susceptibility testing. Phylogenetic and comparative genomic analysis were performed to explore the characteristics of carbapenem-resistant P. mirabilis isolates worldwide. ResultsP. mirabilis XH983 was isolated from the blood of a patient in Hangzhou, China. The genome of XH983 contained one 4128,916 bp circular chromosome and one 24,225 bp IncN plasmid harboring blaKPC-2. P. mirabilis XH983 had multiple resistance genes, conferring resistance to aminoglycosides [aph(3')-Ia, aph(3'')-Ib, aph(6)-Id, aac(3)-IId, aadA5, aadA1], β-lactams (blaKPC-2, blaTEM-1B), phenicol (cat, catA1), sulphonamide/trimethoprim (drfA1, drfA17, sul1, sul2) and tetracycline [tet(J)]. The phylogenetic tree showed that XH983 was present in a cluster of 30 isolates, all of which carried blaKPC-2 and most of them came from the same hospital as XH983, indicating the clonal spread of the cluster. ConclusionWe characterized carbapenem-resistant P. mirabilis clinical isolate XH983. The genome sequence of P. mirabilis XH983 provides information about resistance mechanisms of P. mirabilis carrying the blaKPC-2 plasmid and the potential spread of blaKPC-2.

Epidemic characteristics of the SXT/R391 integrated conjugative elements in multidrug-resistant Proteus mirabilis isolated from chicken farm

This study was designed to depict prevalence and antimicrobial resistance characteristics of Proteus mirabilis (P. mirabilis) strains in 4 chicken farms and to probe the transfer mechanism of resistance genes. A total of 187 P. mirabilis isolates were isolated from 4 chicken farms. The susceptibility testing of these isolates to 14 antimicrobials showed that the multidrug resistance (MDR) rate was as high as 100%. The β-lactamase resistance genes blaOXA-1, blaCTX-M-1G, blaCTX-M-9G and colistin resistance gene mcr-1 were highly carried in the P. mirabilis isolates. An MDR strain W47 was selected for whole genome sequencing (WGS) and conjugation experiment. The results showed that W47 carried 23 resistance genes and 64 virulence genes, and an SXT/R391 integrated conjugative elements (ICEs) named ICEPmiChn5 carrying 17 genes was identified in chromosome. ICEPmiChn5 was able to be excised from the chromosome of W47 forming a circular intermediate, but repeated conjugation experiments were unsuccessful. Among 187 P. mirabilis isolates, 144 (77.01%, 144/187) isolates carried ICEPmiChn5-like ICEs, suggesting that ICEs may be the major vector for the transmission of resistance genes among MDR chicken P. mirabilis strains in this study. The findings were conducive to insight into the resistance mechanism of chicken P. mirabilis strains and provide a theoretical basis for the use of antibiotics for the treatment of MDR P. mirabilis infections in veterinary clinic.

Prevalence, antibiotic resistance patterns, and biofilm formation ability of Enterobacterales recovered from food of animal origin in Egypt.

The majority of animal-derived food safety studies have focused on foodborne zoonotic agents; however, members of the opportunistic Enterobacteriaceae (Ops) family are increasingly implicated in foodborne and public health crises due to their robust evolution of acquiring antimicrobial resistance and biofilms, consequently require thorough characterization, particularly in the Egyptian food sector. Therefore, this study aimed to determine the distribution and prevalence of Enterobacteriaceae family members in animal-derived foods, as well as their resistance to important antimicrobials and biofilm-forming potential. A total of 274 beef, rabbit meat, chicken meat, egg, butter, and milk samples were investigated for the presence of Enterobacteriaceae. All isolated strains were first recognized using traditional microbiological techniques. Following that, matrix-assisted laser desorption ionization-time of flight mass spectrometry was used to validate the Enterobacteriaceae's identity. The isolated enterobacteria strains were tested on disk diffusion and crystal violet quantitative microtiter plates to determine their antibiotic resistance and capacity to form biofilms. There have been thirty isolates of Enterobacteriaceae from seven different species and four genera. Out of the three food types, Pseudomonas aeruginosa had the highest prevalence rate (4.1%). With three species, Enterobacter genera had the second-highest prevalence (3.28%) across five different food categories. In four different food types, the Klebsiella genera had the second-highest distribution and third-highest incidence (2.55%). Almost all isolates, except three Proteus mirabilis, showed prominent levels of resistance, particularly to beta-lactam antibiotics. Except for two Enterobacter cloacae and three P. mirabilis isolates, all isolates were classified as multidrug-resistant (MDR) orextensively multidrug-resistant (XDR). The multiple antibiotic resistance index (MARI) of the majority of isolates dropped between 0.273 and 0.727. The highest MARI was conferred by Klebsiella pneumoniae, at 0.727. Overall, 83.33% of the isolates had strong biofilm capacity, while only 16.67% exhibited moderate capacity. The MDR, XDR, and strong biofilm indicators confirmed in 83.33% of the currently tested Enterobacteriaceae from animal-derived foods suggest that, if not addressed, there may be rising risks to Egypt's economy and public health.

Molecular characterization of Proteus mirabilis virulence factors isolated from patients with otitis media in Diwaniyah, Iraq

The current study's goal was to identify virulence factors (genes) in P. mirabilis. A total of 25/100 (25%) Proteus mirabilis were obtained from patients with otitis media and identified using culture and biochemical characteristics, and Polymerase chain reaction (PCR). The PCR technique was used to detect the 16S rRNA gene and all virulence factors, including the ureC gene, which encodes urease synthesis, the flaA gene, which encodes flagella and fimbriae production, the hpmA gene, which encodes hemolysin production, and the zapA gene, which encodes protease. The results revealed that Proteus mirabilis isolates have 100% of the 16S rRNA gene, 100% of the ureC gene, 95% of the flaA gene, 95% of the hpmA gene, and 100% of the zapA gene.

Studying of antagonistic activity of some probiotics against bacteria P.mirabilis isolated from kidney stones

This study Included (68)gritkidneys samples collected from patients undergoingsurgerylin hospitals in Tikrit city from periodbetween April 2012to May2013.
 The results showed that (64.71%) of males and (35.29 %) of females were infected, the propotion of males to females (1.83: 1).
 Results of biochemical tests and API-20system showed that E.coli and Ps.aeruginosa were the most frequent bacterial isolates among other isolated bacterial species with percentage (30.76%) and (21.22%), respectively, while P. mirabilis was (15.38%) followed by bacteria and Kl.pneumoniae Citrobacter. freundii with isolation percentage (9.6%) and (5.67%) respectively. other species such as (Staph. aureus,, Acinetobacter. freundii, E.faecalis Serratia. marscenes) accounted (1.92%).
 Antigonstic activity of six types of probiotics against P. mirabilis were studied. Results showed that all probiotics types showed inhibition activity against P.mirabilis isolates and diameter of inhibition zone was highest (21.6 ml), when probiotic L. delbruckii used, while L. acidophilus showed less inhibitory activity against P. mirabilis isolate, the diameter of inhibition zone was 15.1.

Laser ablation mediated ZnO nanoparticles inhibit growth and biofilm forming potential of urinary tract bacterium Proteus mirabilis

Zinc oxide (ZnO) nanoparticles (NPs) were formed via the laser ablation technique of a zinc (Zn) target immersed in deionised water (DIW). The optical, structural, and morphological features of these ZnO NPs were investigated using UV/Vis spectrophotometry, x-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Fourier transforms infrared spectroscopy. XRD results of zinc oxide nanoparticles showed diffraction peaks at 32°, 34.5°, 36.5°, 57°, and 67° corresponding to the (100), (002), (101), (110) and (103). The average nanoparticle size was 21 nm. The TEM images of zinc oxide nanoparticles show that they are spherical in shape and have a size distribution of 20–70 nm. The antibacterial activity of the ZnO NPs was determined and compared with Ciprofloxacin against Proteus mirabilis isolates. The ZnO NPs have significant antibacterial activity against P. mirabilis isolates compared with the control (P ≤ 0.05), and the antibiofilm activity of ZnO NPs was sturdier than that of Ciprofloxacin (P ≤ 0.05). In addition, zinc oxide NPs were more effective than Ciprofloxacin in terms of preventing biofilm formation in the urinary catheter. This finding was confirmed by using atomic force microscopy to investigate the effect of ZnO NPs on bacterial biofilm formation in Foleys catheter (AFM). Therefore, ZnO NPs could be used as a preservative for Foleys catheter by preventing the formation of microbial biofilms. DPPH assay was used to investigate the radical scavenging potential of ZnO NPs.

Whole-Genome Analysis of blaNDM-Bearing Proteus mirabilis Isolates and mcr-1-Positive Escherichia coli Isolates Carrying blaNDM from the Same Fresh Vegetables in China.

The global spread of colistin or carbapenem-resistant Enterobacteriaceae (CRE) has been a pressing threat to public health. Members of Enterobacteriaceae, especially Proteus mirabilis and Escherichia coli, have been prevalent foodborne pathogens and such pathogens from fresh vegetables have triggered foodborne illness in China. However, reports about CRE, especially P. mirabilis from fresh vegetables, are still lacking. In this study, we identified five blaNDM-positive P. mirabilis and five blaNDM-positive generic E. coli concurrently from five fresh vegetables in two markets from China, and four of the five E. coli also carried mcr-1. The 10 isolates were characterized with methods including antimicrobial susceptibility testing, conjugation, whole-genome sequencing and phylogenetic analysis. All 10 isolates were multidrug-resistant (MDR). blaNDM-5 in five E. coli isolates and one P. mirabilis carrying blaNDM-5 was located on similarly transferable IncX3 plasmids, while transferably untypable plasmids were the carriers of blaNDM-1 in four P. mirabilis isolates from different types of vegetables/markets. mcr-1 in the four blaNDM-5-positive E. coli was located on similarly non-conjugative IncHI2 MDR plasmids lacking transfer region. Notably, ISCR1 complex class 1 integron capable of capturing blaNDM-1 was found on all untypable plasmids from P. mirabilis, and five copies of ISCR1 complex class 1 integron containing blaNDM-1 even occurred in one P. mirabilis, which showed high-level carbapenem resistance. Plasmid and phylogenetic analysis revealed that the blaNDM-positive P. mirabilis and E. coli from fresh vegetables might be derived from animals and transmitted to humans via the food chain. The concurrence of blaNDM-positive P. mirabilis and E. coli carrying both mcr-1 and blaNDM in different types of fresh vegetables eaten raw is alarming and threatens food safety. Sustained surveillance of these foodborne pathogens among fresh vegetables is urgent to ensure the health of food consumers. We report for the first time the concurrence of blaNDM-positive P. mirabilis and mcr-1-bearing E. coli carrying blaNDM from the same fresh vegetables.

Antibiotic susceptibility of Proteus Mirabillis that isolates of Diabetic foot ulcers in Al- Diwaniyah Hospital

The current study have been included 250 samples diabetic foot ulcer patients attending in Al-Diwaniyah Teaching Hospital and private clinics at a period of study from beginning October 2021 to February 2022, Isolates were identified by morphological form on blood agar and macConkey agar, traditional biochemical tests and then confirmed by Vitek 2 system. The result of bacterial culture have been recorded that only 80 samples had positive result to P. mirabilis formed (32%) of this result. Prevalence of P. mirabilis isolates in male more than female (34.78%) and (28.57%) respectively, after then were determination of antibiotics susceptibility pattern of recovered isolates. The isolates showed that (100%) were resistant to penicillin G, ( 85%) Cephalexin , (75%) Cefotaxime, (100%) Ampicillin, (56.25%) Gentamycin, (35%) Amikacin,(100%) Amoxicillin / Clavulanic Acid, (58.75%) Chloramphenicol, (20%) Meropenem, (100%) Tetracycline, (22.5%) Imipenem, (83%) Streptomycin

Pathogenicity Characteristics of Proteus Mirabilis in Patients with UTI

A total. of two hundred., and fifty urine samples are gathered from hospitals of Thi-Qar governorate over a six-month period, these samples were collected from Al- Nasiriyah teaching hospital, Al-Hussein Teaching Hospital, and Suq Al-Shuyoukh general hospital. Twenty-five Proteus mirabilis isolates were identified using their morphology, microscopic features, biochemistry, confirmatory APi 20 E tests, and VITEK II system. The twenty-five isolates were examined for antibiotic resistance against 18 different antibiotics. It was found that isolates' levels of antibiotic resistance varied. Amoxicillin-clavulanic acid, azithromycin, nitrofurantoin, and ampicillin were all reported to have high resistance among isolates (100 %) while the resistance to activity of trimethoprim, tetracycline, and cefotaxime was 96%. The resistance to nalidixic acid, cefepime, ceftriaxone, ciprofloxacin, ceftazidime, amikacin, cefixime, gentamicin, norfloxacin, imipenem, and meropenem were (88, 88, 84, 76, 72, 68, 68, 56, 52, 8, 16) % respectively.

Antibiotic susceptibility of P. mirabilis isolated from clinical samples in Thi- Qar province

Proteus spp. Is a motile dimorphic Gram negative bacteria belonging to the order Enterobacterales. P. mirabilis, the most commonly isolated species from clinical samples. The present study aimed to investigate the resistance of Proteus mirabilis isolates to different antibiotics. The study included the collection of 487 samples from different clinical sources, including urine, burns, wounds, ear swabs and diabetic ulcers. Different ages were involved of both sexes. Samples were collected from patients attending Al-Nasiriya and Al- Hussain Teaching Hospitals and private laboratories in Thi-Qar province, Iraq, from 29th of November 2021 to 20th of Abril 2022. A total of the isolates were diagnosed by different laboratory tests. The prevalence of P. mirabilis was 8.6 % among all collected samples. Female infection rate was 52.4%, male infection rate was 47.6 %. The age group ≥ 44 years was most commonly infected with P. mirabilis. In addition most P. mirabilis isolates were obtained from UTIs 45%. The antibiotic susceptibility test results showed a high resistance for Cefepime 83.3%, Ceftriaxone 78.8%, Tobramycin 73.3%, Ampicillin 71.4%, Amoxicillin/clavulanic Acid 69%, and Cefotaxime 60%. However, ciprofloxacin was the highest effective antibiotic 54.7%, followed by Meropenem 50%, and Gentamicin 45%. Finally, amikacin had intermediate activity 19%, followed by Netilmicin 16.6%.

Analysis of Extended Spectrum Beta Lactamase (ESBL) Genes of Non-Invasive ESBL Enterobacterales in Southeast Austria in 2017.

Extended spectrum beta lactamases producing Enterobacteriaceae are a major player in the antibiotic resistance challenge. In general, the situation regarding antibiotic resistance in Austria is very good compared to many other countries. Perhaps this is why there is a lack of data on the distribution of ESBL genes in the clinical setting. The aim of this study was to collect data on ESBL genes from a larger sample of human non-invasive clinical isolates from one region in Austria. In total, 468 isolates from different sample materials isolated at the Medical University of Graz from 2017 were examined. The most frequent organisms were Escherichia coli and Klebsiella pneumoniae. Among the enzymes produced, CTX-M-15 was clearly dominant, exotic ESBLs were only represented by three Proteus mirabilis isolates harboring genes for VEB-6 and one P. mirabilis for CTX-M-2, respectively. Compared to other countries, the results are in line with the expectations. The data help to better classify the many studies from the non-clinical field in Austria and to shift the focus slightly away from the exotic results and sample sites.

2036. Dual VIM-producing Proteus mirabilis, Including a Novel VIM-75, Among Elderly Patients in a Medical Center from Hungary: Report from the 2020 SENTRY Antimicrobial Surveillance Program

Abstract Background Nonsusceptibility of Proteus mirabilis to imipenem allows this pathogen evade surveillance for carbapenemases. Metallo-beta-lactamases of the VIM family are widespread among Enterobacterales in Europe. We identified an outbreak of P. mirabilis carrying 2 VIM enzymes among elderly patients from a medical center in Hungary. Methods A total of 16 P. mirabilis isolates were received from Hungary during 2020 as part of the SENTRY Antimicrobial Surveillance Program. Isolates were susceptibility tested by the CLSI reference broth microdilution method. Carbapenem-nonsusceptible isolates were submitted to whole genome sequencing, screened for resistance mechanisms, and evaluated for core genome multi-locus sequence typing (cgMLST). Results Among the 16 P. mirabilis isolates from Hungary, 5 carbapenem-nonsusceptible, multidrug-resistant isolates (3 from urinary tract infections and 1 each from bloodstream infection and pneumonia) were identified from patients 66-92 years old. Four of these 5 isolates were listed as community acquired. All isolates were resistant to ceftriaxone (MIC, > 8 mg/L), cefepime (16- > 32), imipenem ( > 8), gentamicin ( > 16), levofloxacin (16- > 32), nitrofurantoin ( > 64), trimethoprim/sulfamethoxazole ( > 4), and plazomicin ( > 128), but susceptible to meropenem (0.25-0.5) and ertapenem (0.03-0.25). Isolates carried blaVIM-4 and blaVIM-75 on a class 1 integron within IS26 and separated by aac(6’)-IIc. IS26 was located on a compound plasmid carrying other resistance-encoding genes, including armA. The integron structure is identical to the blaVIM-4 and blaVIM-1-carrying integron described from a Vibrio cholerae isolated from a seagull in France in 2015 (KR262557). blaVIM-75 is a single amino acid variant (Q60R) of blaVIM-1. All isolates carried mutations in the QRDR (gyrA_S83I, parC_S84I). Based on cgMLST analysis, these 5 P. mirabilis isolates were highly similar, with only 7-19 SNPs detected. Conclusion The outbreak of multidrug-resistant P. mirabilis isolates carrying blaVIM-4 and blaVIM-75 in a Hungarian medical center is a cause of concern. Surveillance should be performed to understand the spread of and treatment options for infections caused by carbapenem-nonsusceptible P. mirabilis. Disclosures Lalitagauri M. Deshpande, PhD, Melinta: Grant/Research Support|Pfizer: Grant/Research Support Katalin Burián, MD, JMI Laboratories: Grant/Research Support Ilona Dóczi Csányi, MD, JMI Laboratories: Grant/Research Support Mariana Castanheira, PhD, AbbVie: Grant/Research Support|Cidara: Grant/Research Support|GSK: Grant/Research Support|Melinta: Grant/Research Support|Pfizer: Grant/Research Support|Shionogi: Grant/Research Support.

1794. Evaluation of Antimicrobial Susceptibility Patterns for Patients Admitted from Post-Acute Care Facilities in the Philadelphia Region

Abstract Background Antimicrobial resistance is a rapidly emerging threat and antibiograms are a key component in guiding empiric antimicrobial selection. Patients admitted from post-acute care facilities (PACF) are at a heightened risk for infections from multi-drug resistant organisms, posing a challenge for clinicians selecting empiric therapy. It is uncommon for antibiograms to differentiate between sources of admission. This study aimed to characterize culture proven infections and the appropriateness of empiric antimicrobial regimens for patients admitted from PACF in the Philadelphia region. Methods This was a retrospective quality improvement study that included patients admitted from Philadelphia PACF from August 2020 to June 2021. Patients were included if they had at least one positive culture within 72 hours of admission. Appropriate therapy was determined based on a comparison of empiric antimicrobial selection and susceptibilities that resulted from collected cultures. Descriptive statistics were employed for data analysis. Results A total of 106 patients and 154 cultures were evaluated during the study period. The majority of patients received initial empiric coverage for Pseudomonas aeruginosa (79%) and methicillin-resistant Staphylococcus aureus (59%). Over 50% of all cultures had been obtained from urinary sources. Enterococcus spp. were the most commonly isolated gram positive organism (61%) and Escherichia coli was the most common gram negative organism (33%). A portion of patients (32.7%) did not receive appropriate empiric therapy. Discrepancies in susceptibility patterns between our internal antibiogram and PACF patients were most notable for gram negative organisms including decreased levofloxacin susceptibilities to P. mirabilis isolates (89% vs 45%). Other notable discrepancies include decreased meropenem susceptibilities to P. aeruginosa isolates (88% vs 65%). Select susceptibility patterns are reported in Figure 1. Conclusion Antimicrobial susceptibility was discordant amongst patients admitted from PACF in the Philadelphia region compared to our general antibiogram. The increased resistance identified supports a need to re-evaluate empiric prescribing guidelines for this specific population. Disclosures All Authors: No reported disclosures.

1836. Frequency and Antimicrobial Susceptibility of Gram-negative Bacteria Isolated from Patients with Bloodstream Infections in United States (US) Medical Centers (2020-2021)

Abstract Background Antimicrobial resistance among Gram-negative bacteria (GNB) is a major problem in US hospitals. The development of various β-lactamase inhibitor combinations (BLICs) markedly increased the armamentarium to treat infections caused by GNB in recent years. We evaluated the frequency and antimicrobial susceptibility of GNB causing bloodstream infection (BSI). Methods 5,796 organisms were consecutively collected (1/patient) from patients with BSI in 31 US medical centers in 2020-2021. The collection included 2,893 (49.9%) GNB, which were susceptibility tested against ceftazidime-avibactam (CAZ-AVI), ceftolozane-tazobactam (C-T), meropenem-vaborbactam (MEM-VAB), imipenem-relebactam (IMI-REL), and many comparators by CLSI broth microdilution method. Enterobacterales (ENT) isolates with an ESBL phenotype were screened for β-lactamase genes by whole genome sequencing. Results The most common GNBs were E. coli (41.9%), K. pneumoniae (16.1%), P. aeruginosa (10.2%), and E. cloacae (6.8%). Ceftriaxone susceptibility rates were 80.1%, 82.9%, and 74.0% for E. coli, K. pneumoniae, and E. cloacae, respectively. CAZ-AVI and MEM-VAB showed almost complete activity (≥ 99.7%) against ENT, whereas IMI-REL exhibited limited activity against P. mirabilis and indole-positive Proteeae isolates and C-T showed limited activity against E. cloacae, ESBL-phenotype, and multidrug-resistant (MDR) isolates (Table). CAZ-AVI, MEM-VAB, and IMI-REL were active against 84.2%, 57.9%, and 52.6% of carbapenem-resistant ENT (CRE) isolates, respectively. PSA susceptibility to PIP-TAZ, MEM, and CAZ were 86.1%, 88.5%, and 88.5%, respectively. CAZ-AVI (97.6% susceptible [S]), C-T (97.6%S), IMI-REL (99.0%S), and tobramycin (TOB; 98.3%S) were the most active agents against PSA and retained good activity against piperacillin-tazobactam (PIP-TAZ) nonsusceptible (NS), MEM-NS, and multidrug-resistant (MDR) isolates. Conclusion CAZ-AVI and MEM-VAB were the most active agents against ENT and CAZ-AVI; C-T and IMI-REL were the most active BLICs against PSA. The new BLICs represent valuable treatment options for infections caused by MDR GBNs. CAZ-AVI exhibited a more balanced spectrum against ENT and PSA when compared to other BLICs. Disclosures Helio S. Sader, MD, PhD, AbbVie: Grant/Research Support|Cidara: Grant/Research Support|Melinta: Grant/Research Support|Nabriva Therapeutics: Grant/Research Support|Pfizer: Grant/Research Support Rodrigo E. Mendes, PhD, AbbVie: Grant/Research Support|Cidara: Grant/Research Support|GSK: Grant/Research Support|Melinta: Grant/Research Support|Nabriva Therapeutics: Grant/Research Support|Office for Assistant Secretary of Defense for Health Affairs: Grant/Research Support|Pfizer: Grant/Research Support|Shionogi: Grant/Research Support|Spero Therapeutics: Grant/Research Support Cecilia G. Carvalhaes, MD, PhD, AbbVie: Grant/Research Support|Cidara: Grant/Research Support|Melinta: Grant/Research Support|Pfizer: Grant/Research Support Michael D. Huband, BS, AbbVie: Grant/Research Support|Melinta: Grant/Research Support Dee Shortridge, PhD, AbbVie: Grant/Research Support|JMI Laboratory: Employee|Melinta: Grant/Research Support|Menarini: Grant/Research Support|Shionogi: Grant/Research Support Mariana Castanheira, PhD, AbbVie: Grant/Research Support|Cidara: Grant/Research Support|GSK: Grant/Research Support|Melinta: Grant/Research Support|Pfizer: Grant/Research Support|Shionogi: Grant/Research Support.

Antimicrobial resistance patterns of bacteria isolated from chicks of Canarian Egyptian vultures (Neophron percnopterus majorensis): A “one health” problem?

Antimicrobial resistance in Gram-negative bacteria isolated from cloacal samples of chicks of Canarian Egyptian vultures was investigated. Prevalence of Salmonella was also studied. Forty-seven isolates, obtained from 23 animals, were analysed. Escherichia coli (n = 29), Proteus mirabilis (n = 17) and Salmonella spp. (n = 1) were identified using API 20E system. Antimicrobial susceptibility to 13 antibiotics included in nine different categories was determined using disk-diffusion technique. The higher percentages of susceptible E. coli isolates were found for aminoglycosides and cefoxitin, and the lower ones were found for ampicillin, enrofloxacin and tetracycline. Proteus mirabilis isolates were susceptible to most of antimicrobials tested. Multidrug resistance patterns were found in 13 E. coli and four Proteus mirabilis. Salmonella spp. was detected in one chick (4.37%), and the isolate was also resistant to ampicillin and tetracycline. Thirteen E. coli isolates and four Proteus isolates showed a multidrug-resistance pattern, being resistant at least to one antibiotic in three or more different antimicrobial categories. This high level of antibiotic resistance in chickens of an endangered bird may be a limitation for possible treatments of infections in this species, as well as representing a source of resistant bacteria for animal care staff and for other animals in wildlife recovery centres. A “One Health” approach to this problem is necessary to reduce the levels of antimicrobial resistance in wild birds.

Study of Some Resistance Genes in Clinical Proteus mirabilis.

Proteus mirabilis belongs to the family Enterobacteriaceae and is capable of transforming in shape from rod to elongated and swarming motility by flagella. It is an opportunity for bacteria and can cause different clinical diseases. Therefore, this study aimed to assay and detect a sequence of genes that encode for antibiotic resistance in multidrug resistance clinical isolates of Proteus mirabilis, including blaTEM, aac(6')-Ib, qnrA, IntI2, IntI1 and secondly to investigate the relationship in the phylogenetic tree among these genes in Iraq comparison with global strains in NCBI. The study included the identifying of 500 clinical samples depending on morphological and biochemical tests and confirming Proteus mirabilis diagnosis by the VITEK-2 Compact system. The confirmed isolates of Proteus mirabilis were 95 clinical isolates (19%). Antibiotic susceptibility test of all these isolates was done using twelve antibiotics tested using Amoxicillin, Aztreonam, Imipenem, Cefoxitin, Amikacin, Ceftazidem, Ciprofloxacin, Nalidixic acid, Gentamicin, Sulphamethazol-trimethoprim, Cefotaxime, Amoxicillin-clavulanic acid. The results showed that multidrug resistance Proteus mirabilis isolates contained the genes in different levels as follow blaTEM gene (90%), aac(6')-Ib gene (80%) ,IntI1 gene (100%), IntI2 gene (80%). These genes were sequenced and detected phylogenetic relationships among these genes and global genes were documented in NCBI. The results showed that some Iraqi isolates contain genetic variation compared to global strains. Therefore, this variation was detected and registered in NCBI of all five antibiotic resistance genes mentioned above and accepted under accession numbers of aacIb gene (LC613168.1), blaTEM gene (LC613166.1), IntI1 gene (LC613169.1), IntI2 gene (LC613170.1).