Proteus species bloodstream infections: Comparative epidemiology of three species.

BACKGROUND: Although Proteus species are occasional causes of serious infections, their epidemiology has not been well defined. The objective was to describe the overall and species-specific occurrence and determinants of Proteus species bloodstream infection (BSI) in a large Australian population. METHODS: All Queensland residents with Proteus species BSI identified within the publicly funded healthcare system between 2000 and 2019 were included. RESULTS: A total of 2,143 incident episodes of Proteus species BSI were identified among 2,079 Queensland residents. The prevalence of comorbid illness differed with higher Charlson comorbidity scores observed with P. penneri and P. vulgaris, and higher prevalence of liver disease with P. penneri, higher comorbid cancer with P. vulgaris, and lower diabetes and renal disease prevalence with P. mirabilis BSIs. CONCLUSION: This study provides novel information on the epidemiology of Proteus species BSI.

Isolation, characterization and antibiotic resistance of Proteus mirabilis from Belgian broiler carcasses at retail and human stool.

Proteus mirabilis is an important pathogen involved in human urinary tract infections, and also more isolated from stools of patients with diarrheal disease than from healthy patients. The role of food, especially poultry products as source for human infection and multi-resistant strains remains unclear. As a resident in broilers' intestines, P. mirabilis can contaminate broiler carcasses due to slaughter practices, and be a risk for human infection. The present study evaluated the performance of five isolation media, and subsequently examined the presence of P. mirabilis on broiler carcasses at retail. Additionally, isolates were characterized by the Dienes' test, repetitive element PCR fingerprinting and pulsed-field gel electrophoresis, and their antibiotic resistance profile determined. Using a combined isolation protocol on blood agar, xylose lysine deoxycholate agar and violet red bile glucose agar, P. mirabilis was isolated from 29 out of 80 broiler carcasses (36.25%) with a mean contamination level of 2.25 ± 0.50 log10 CFU/g. A high strain heterogeneity was present in isolates from broilers and human stool. The same strains were not shared, but the antibiotic resistance profiling was similar. A role of poultry products as source for human infection should be taken into account.

Clonal outbreak caused by VIM-4-producing Proteus mirabilis in a Greek tertiary-care hospital.

Carbapenem-resistant Enterobacterales have become a major public-health issue worldwide. Here we report an outbreak caused by a clonal multidrug-resistant Proteus mirabilis strain producing VIM-4 metallo-ß-lactamase (MBL) and TEM-2 ß-lactamase in a Greek tertiary-care hospital. From July 2015 to February 2016, 27 imipenem-resistant P. mirabilis isolates were recovered from 14 patients hospitalised in two intensive care units (ICUs) and the internal medicine department in AHEPA University Hospital, Thessaloniki. The isolates were either susceptible or resistant to meropenem and were resistant to all remaining ß-lactams except aztreonam. Phenotypic and molecular analysis revealed that all of the isolates harboured a blaVIM-4 MBL gene. Resistome analysis of a representative isolate showed the presence of an IncQ1 plasmid harbouring the blaVIM-4 carbapenemase and blaTEM-2 ß-lactamase genes among resistance genes coding for resistance to ß-lactams, aminoglycosides, trimethoprim, sulfonamides and lincosamides. Genotyping by pulsed-field electrophoresis (PFGE) revealed that the isolates were epidemiologically related. After recovery of the index carbapenemase-producing P. mirabilis clinical isolate, infection control measures were intensified in the affected departments. Rectal sampling for carbapenem-resistant bacteria was initiated on a weekly basis among patients admitted to the general ICU. The outbreak was finally interrupted 6 months later in February 2016. This is the first documentation of the blaVIM-4 MBL gene in P. mirabilis as well as the first hospital outbreak caused by a MBL-producing P. mirabilis strain.

Isolation, nucleotide sequencing and genomic comparison of a Novel SXT/R391 ICE mobile genetic element isolated from a municipal wastewater environment.

Integrative Conjugative Elements (ICE's) of the SXT/R391 family have largely been detected in clinical or environmental isolates of Gammaproteobacteria, particularly Vibrio and Proteus species. As wastewater treatment plants accumulate a large and diverse number of such species, we examined raw water samples taken from a municipal wastewater treatment plant initially using SXT/R391 family integrase gene-specific PCR probes to detect the presence of such elements in a directed approach. A positive amplification occurred over a full year period and a subsequent Restriction Fragment Length Polymorphism (RFLP) analysis revealed a very limited diversity in the treatment plant examined. Samples demonstrating positive amplification were cultured using Vibrio and Proteus selective media and PCR amplification tracking was utilized to monitor SXT/R391-ICE family containing strains. This screening procedure resulted in the isolation and identification of a Proteus mirabilis strain harbouring an ICE. Whole-genome sequencing of this ICE containing strain using Illumina sequencing technology revealed a novel 81 kb element that contained 75 open reading frames on annotation but contained no antibiotic or metal resistance determinants. Comparative genomics revealed the element contained a conserved ICE core with one of the insertions containing a novel bacteriophage defence mechanism. This directed isolation suggests that ICE elements are present in the environment without apparent selective pressure but may contain adaptive functions allowing survival in particular environments such as municipal wastewater which are reservoirs for large bacterial phage populations.

Rapid identification of pathogenic bacteria using Raman spectroscopy and deep learning.

Raman optical spectroscopy promises label-free bacterial detection, identification, and antibiotic susceptibility testing in a single step. However, achieving clinically relevant speeds and accuracies remains challenging due to weak Raman signal from bacterial cells and numerous bacterial species and phenotypes. Here we generate an extensive dataset of bacterial Raman spectra and apply deep learning approaches to accurately identify 30 common bacterial pathogens. Even on low signal-to-noise spectra, we achieve average isolate-level accuracies exceeding 82% and antibiotic treatment identification accuracies of 97.0±0.3%. We also show that this approach distinguishes between methicillin-resistant and -susceptible isolates of Staphylococcus aureus (MRSA and MSSA) with 89±0.1% accuracy. We validate our results on clinical isolates from 50 patients. Using just 10 bacterial spectra from each patient isolate, we achieve treatment identification accuracies of 99.7%. Our approach has potential for culture-free pathogen identification and antibiotic susceptibility testing, and could be readily extended for diagnostics on blood, urine, and sputum.

Bacterial isolation and antibiotic susceptibility from diabetic foot ulcers in Kenya using microbiological tests and comparison with RT-PCR in detection of S. aureus and MRSA.

OBJECTIVES: Diabetic foot ulcers (DFUs) often lead to hospital admissions, amputations and deaths; however, there is no up-to-date information on microbial isolates from DFUs and no mention of utilization of molecular techniques in Sub-Saharan Africa. We conducted a cross-sectional study among 83 adult patients at a tertiary hospital in Kenya over 12 months. The study aimed to isolate, identify bacteria, their antibiotic susceptibility patterns in active DFUs, and to compare standard microbiological methods versus a real-time PCR commercial kit in the detection of Staphylococcus aureus DNA and methicillin-resistant S. aureus (MRSA) DNA. RESULTS: Eighty swabs (94%) were culture-positive; 29% were Gram-positive and 65% were Gram-negative. The main organisms isolated were S. aureus (16%), Escherichia coli (15%), Proteus mirabilis (11%), Klebsiella pneumoniae (7%) and Pseudomonas aeruginosa (7%). The bacterial isolates showed resistance to commonly used antibiotics such as ampicillin, amoxicillin, cefepime, ceftazidime, cefuroxime, clindamycin, erythromycin, piperacillin-tazobactam, tetracycline and trimethoprim-sulphamethoxazole (TMPSMX). Thirty-one percent of the S. aureus isolated and 40% of the Gram-negatives were multi-drug resistant organisms (MDROs). There was a high prevalence of nosocomial bacteria. MRSA were not identified using culture methods but were identified using PCR. PCR was more sensitive but less specific than culture-based methods to identify S. aureus.

Genotypic and phenotypic profiles of virulence factors and antimicrobial resistance of Proteus mirabilis isolated from chicken carcasses: potential zoonotic risk.

Proteus mirabilis is an opportunistic pathogen often associated with a variety of human infections acquired both in the community and in hospitals. In this context, the present work aimed to evaluate the genotypic and phenotypic characteristics of the virulence factors and antimicrobial resistance determinants of 32 P. mirabilis strains isolated from chicken carcasses in a poultry slaughterhouse in the north of the state of Paraná, Brazil, in order to assess a potential zoonotic risk. The isolates presented a variety of virulence genes that contribute to the development of infection in humans. The mrpA, pmfA, atfA (fimbriae), ireA (siderophores receptor), zapA, ptA (Proteases), and hpmA (hemolysin) genes were found in 32 (100%) isolates and ucaA (fimbriae) in 16 (50%). All isolates showed aggregative adherence in HEp-2 cells and formed biofilms. Of all strains, 27 (84.38%) showed cytotoxic effects in Vero cells. Antimicrobial susceptibility was tested using 20 antimicrobials, in which 25 (78.13%) strains were considered multidrug-resistant. The presence of blaESBL and blaampC genes conferring resistance to ß-lactams and qnr to quinolones were also detected in the isolates after presumption in the phenotypic test, in which 7 (21.88%) isolates contained the CTX-M-2 group, 11 (34.38%) contained CIT group and 19 (59.38%) contained qnrD. Therefore, chicken carcasses contaminated with P. mirabilis may pose a health risk to the consumer, as these isolates have a variety of virulence and antimicrobial resistance characteristics that can be found in P. mirabilis strains isolated from human infections.

Genome sequencing and analysis of the first spontaneous Nanosilver resistant bacterium Proteus mirabilis strain SCDR1.

Background: P. mirabilis is a common uropathogenic bacterium that can cause major complications in patients with long-standing indwelling catheters or patients with urinary tract anomalies. In addition, P. mirabilis is a common cause of chronic osteomyelitis in Diabetic foot ulcer (DFU) patients. We isolated P. mirabilis SCDR1 from a Diabetic ulcer patient. We examined P. mirabilis SCDR1 levels of resistance against Nanosilver colloids, the commercial Nanosilver and silver containing bandages and commonly used antibiotics. We utilized next generation sequencing techniques (NGS), bioinformatics, phylogenetic analysis and pathogenomics in the characterization of the infectious pathogen. Results: P. mirabilis SCDR1 was the first Nanosilver resistant isolate collected from a diabetic patient polyclonal infection. P. mirabilis SCDR1 showed high levels of resistance against Nanosilver colloids, Nanosilver chitosan composite and the commercially available Nanosilver and silver bandages. The P. mirabilis -SCDR1 genome size is 3,815,621 bp. with G + C content of 38.44%. P. mirabilis-SCDR1 genome contains a total of 3533 genes, 3414 coding DNA sequence genes, 11, 10, 18 rRNAs (5S, 16S, and 23S), and 76 tRNAs. Our isolate contains all the required pathogenicity and virulence factors to establish a successful infection. P. mirabilis SCDR1 isolate is a potential virulent pathogen that despite its original isolation site, the wound, can establish kidney infection and its associated complications. P. mirabilis SCDR1 contains several mechanisms for antibiotics and metals resistance, including, biofilm formation, swarming mobility, efflux systems, and enzymatic detoxification. Conclusion: P. mirabilis SCDR1 is the first reported spontaneous Nanosilver resistant bacterial strain. P. mirabilis SCDR1 possesses several mechanisms that may lead to the observed Nanosilver resistance.

Biofilm Formation and Immunomodulatory Activity of Proteus mirabilis Clinically Isolated Strains.

Urinary tract infections (UTIs) and catheter-associated UTIs (CAUTIs) are the principal hospital-acquired infections. Proteus mirabilis is characterized by several virulence factors able to promote adhesion and biofilm formation and ameliorate the colonization of urinary tract and the formation of crystalline biofilms on the abiotic surface of the urinary catheters. Since, to date, the role of P. mirabilis in the etiopathogenesis of different types of urinary tract infections is not well established, in this study we sought to characterize two different clinically isolated strains of P. mirabilis (PM1 and PM2) with distinctive phenotypes and analyzed various virulence factors possibly implicated in the ability to induce UTIs and CAUTIs. In particular, we analyzed motility, biofilm formation both on abiotic and biotic surfaces of PM1 and PM2 and paralleled these parameters with the ability to induce an inflammatory response in an epithelial cell model. Results showed that PM1 displayed major motility and a capacity to form biofilm and was associated with an anti-inflammatory response of host cells. Conversely, PM2 exhibited lack motility and a had slower organization in biofilm but promoted an increase of proinflammatory cytokine expression in infected epithelial cells. Our study provides data useful to start uncovering the pathologic basis of P. mirabilis-associated urinary infections. The evidence of different virulence factors expressed by PM1 and PM2 highlights the possibility to use precise and personalized therapies targeting specific virulence pathways.

Chromosomal location of the fosA3 and blaCTX-M genes in Proteus mirabilis and clonal spread of Escherichia coli ST117 carrying fosA3-positive IncHI2/ST3 or F2:A-:B- plasmids in a chicken farm.

The aim of this study was to investigate the spread and location of the fosA3 gene among Enterobacteriaceae from diseased broiler chickens. Twenty-nine Escherichia coli and seven Proteus mirabilis isolates recovered from one chicken farm were screened for the presence of plasmid-mediated fosfomycin resistance genes by PCR. The clonal relatedness of fosA3-positive isolates, the transferability and location of fosA3, and the genetic context of the fosA3 gene were determined. Seven P. mirabilis isolates with three different pulsed-field gel electrophoresis (PFGE) patterns and five E. coli isolates belonging to sequence type 117 (ST117) and phylogenetic group D were positive for fosA3 and all carried the blaCTX-M gene. In E. coli, the genetic structures IS26-ISEcp1-blaCTX-M-65-IS26-fosA3-1758 bp-IS26 and IS26-ISEcp1-blaCTX-M-3-blaTEM-1-IS26-fosA3-1758 bp-IS26 were present on transferable IncHI2/ST3 and F2:A-:B- plasmids, respectively. However, fosA3 was located on the chromosome of the seven P. mirabilis isolates. IS26-ISEcp1-blaCTX-M-65-IS26-fosA3-1758 bp-IS26 and IS26-blaCTX-M-14-611 bp-fosA3-1222 bp-IS26 were detected in three and four P. mirabilis isolates, respectively. Minicircles that contained both fosA3 and blaCTX-M-65 were shared between E. coli and P. mirabilis. This is the first report of the fosA3 gene integrated into the chromosome of P. mirabilis isolates with the blaCTX-M gene. The emergence and clonal spread of avian pathogenic E. coli ST117 with the feature of multidrug resistance and high virulence are a serious problem.

Regional Spread of CTX-M-2-Producing Proteus mirabilis with the Identical Genetic Structure in Japan.

AIMS: In this study, we analyzed the molecular epidemiology of extended-spectrum ß-lactamase (ESBL)-producing Proteus mirabilis isolates collected from the central region of Japan. MATERIALS AND METHODS: Between 2005 and 2012, 820 clinical P. mirabilis isolates were obtained from ten acute care hospitals in Japan. We characterized ESBL confirmatory test-positive isolates by sequencing the ESBL genes and their flanking regions, detecting plasmid replicons, and performing pulsed-field gel electrophoresis (PFGE). RESULTS: Ninety-six isolates (12%) were positive according to the ESBL confirmatory test; all these isolates possessed blaCTX-M-2 with the same flanking structure of upstream ΔISEcp1 and a downstream region identical to downstream blaKLUA-1. IncT was the prevalent, and only, replicon found in 63 isolates. PFGE analysis detected eight clusters with more than one isolate, among which three included 56 isolates and six included isolates from multiple hospitals. CONCLUSION: CTX-M-2-producing P. mirabilis with an identical genetic structure flanking blaCTX-M-2 is dominant in this Japanese region, and there is evidence for the clonal spread of isolates.

The Pathogenic Potential of Proteus mirabilis Is Enhanced by Other Uropathogens during Polymicrobial Urinary Tract Infection.

Urinary catheter use is prevalent in health care settings, and polymicrobial colonization by urease-positive organisms, such as Proteus mirabilis and Providencia stuartii, commonly occurs with long-term catheterization. We previously demonstrated that coinfection with P. mirabilis and P. stuartii increased overall urease activity in vitro and disease severity in a model of urinary tract infection (UTI). In this study, we expanded these findings to a murine model of catheter-associated UTI (CAUTI), delineated the contribution of enhanced urease activity to coinfection pathogenesis, and screened for enhanced urease activity with other common CAUTI pathogens. In the UTI model, mice coinfected with the two species exhibited higher urine pH values, urolithiasis, bacteremia, and more pronounced tissue damage and inflammation compared to the findings for mice infected with a single species, despite having a similar bacterial burden within the urinary tract. The presence of P. stuartii, regardless of urease production by this organism, was sufficient to enhance P. mirabilis urease activity and increase disease severity, and enhanced urease activity was the predominant factor driving tissue damage and the dissemination of both organisms to the bloodstream during coinfection. These findings were largely recapitulated in the CAUTI model. Other uropathogens also enhanced P. mirabilis urease activity in vitro, including recent clinical isolates of Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, and Pseudomonas aeruginosa We therefore conclude that the underlying mechanism of enhanced urease activity may represent a widespread target for limiting the detrimental consequences of polymicrobial catheter colonization, particularly by P. mirabilis and other urease-positive bacteria.

Structures and serospecificity of threonine-containing O polysaccharides of two clinical isolates belonging to the genus Proteus and their classification into O11 subserogroups.

Two clinical isolates from Polish patients, Proteus mirabilis 9B-m and Proteus genomospecies 3J-r, were found to be serologically related to P mirabilis O11. However, serological studies involving ELISA and Western blotting methods, using lipopolysaccharides (LPSs) extracted from the strains as antigens and native or adsorbed rabbit polyclonal O antisera, specific to the studied strains, revealed slight differences in the cross-reactivity and specificity of the two studied Proteus isolates, when compared to P. mirabilis O11. Two different O polysaccharides containing N-(d-galacturonoyl)-l-threonine were isolated from the LPSs of the isolates. Their structures were determined by chemical analysis and NMR spectroscopy and found to be related to the P. mirabilis O11 antigen structure established earlier, the 9B-m structure differing in the absence of the lateral glucose residue and the 3J-r structure in non-stoichiometric O-acetylation of the threonine residue only. Thus, the Proteus O11 serogroup should be divided into two subgroups: O11a, represented by the 9B-m isolate and O11a, b possessing the additional b epitope, containing the lateral residue of glucose and formed by the 3J-r isolate as well as P. mirabilis 25/57 belonging to O11 serogroup so far. O11a is the sixth new serotype found in Proteus spp. strains recently isolated from patients in central Poland.

Emergence of multidrug-resistant Proteus mirabilis in a long-term care facility in Croatia.

BACKGROUND: An increased frequency of Proteus mirabilis isolates resistant to expanded-spectrum cephalosporins was observed recently in a long-term care facility in Zagreb (Godan). The aim of this study was the molecular characterization of resistance mechanisms to new cephalosporins in P. mirabilis isolates from this nursing home. METHODS: Thirty-eight isolates collected from 2013-2015 showing reduced susceptibility to ceftazidime were investigated. Antibiotic susceptibilities were determined by broth microdilution method. Inhibitor-based tests were performed to detect extended-spectrum (ESBLs) and AmpC ß-lactamases. AmpC ß-lactamases were characterized by polymerase chain reaction (PCR) followed by sequencing of bla ampC genes. Quinolone resistance determinants (qnr genes) were characterized by PCR. Genotyping of the isolates was performed by repetitive element sequence (rep)-PCR and pulsed-field gel electrophoresis (PFGE). RESULTS: Presence of an AmpC ß-lactamase was confirmed in all isolates by combined-disk test with phenylboronic acid. All isolates were resistant to amoxicillin alone and combined with clavulanate, cefotaxime, ceftriaxone, cefoxitin, and ciprofloxacin; but susceptible to cefepime, imipenem, and meropenem. PCR followed by sequencing using primers targeting bla ampc genes revealed CMY-16 ß-lactamase in all but one strain. Bla cmy-16 was carried by a non-conjugative plasmid which did not belong to any known plasmid-based replicon typing (PBRT) group. Rep-PCR identified one large clone consisting of 15 isolates, three pairs or related isolates, one triplet, and four singletons. PFGE confirmed the clonality of the isolates. CONCLUSIONS: This is the first report of multidrug resistant P. mirabilis in a nursing home in Croatia. Cephalosporin resistance was due to plasmid-mediated AmpC ß-lactamase CMY-16.

Chemometric analysis of attenuated total reflectance infrared spectra of Proteus mirabilis strains with defined structures of LPS.

Proteus spp. strains are some of the most important pathogens associated with complicated urinary tract infections and bacteremia affecting patients with immunodeficiency and long-term urinary catheterization. For epidemiological purposes, various molecular typing methods have been developed for this pathogen. However, these methods are labor intensive and time consuming. We evaluated a new method of differentiation between strains. A collection of Proteus spp. strains was analyzed by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy in the mid-infrared region. ATR FT-IR spectroscopy used in conjunction with a diamond ATR accessory directly produced the biochemical profile of the surface chemistry of bacteria. We conclude that a combination of ATR FT-IR spectroscopy and mathematical modeling provides a fast and reliable alternative for discrimination between Proteus isolates, contributing to epidemiological research.

Immunochemical characterization of the O antigens of two Proteus strains, O8-related antigen of Proteus mirabilis 12 B-r and O2-related antigen of Proteus genomospecies 5/6 12 B-k, infecting a hospitalized patient in Poland.

A hospitalized 73-year-old woman was infected with a Proteus mirabilis strain, 12 B-r, isolated from the place of injection of a blood catheter. Another strain, 12 B-k, recognized as Proteus genomospecies 5 or 6, was isolated from the patient's faeces, which was an example of a nosocomial infection rather than an auto-infection. Serological investigation using ELISA and Western blotting showed that strain 12 B-k from faeces belonged to the Proteus O2 serogroup. Strain 12 B-r from the wound displayed cross-reactions with several Proteus O serogroups due to common epitopes on the core or O-specific parts of the lipopolysaccharide. Studies of the isolated 12 B-r O-specific polysaccharide by NMR spectroscopy revealed its close structural similarity to that of Proteus O8. The only difference in 12 B-r was the presence of an additional GlcNAc-linked phosphoethanolamine residue, which creates a putative epitope responsible for the cross-reactivity with Pt. mirabilis O16. The new O-antigen form could appear as a result of adaptation of the bacterium to a changing environment. On the basis of the data obtained, we suggest division of the O8 serogroup into two subgroups: O8a for strains of various Proteus species that have been previously classified into the O8 serogroup, and O8a,b for Pt. mirabilis 12 B-r, where 'a' is a common epitope and 'b' is a phosphoethanolamine-associated epitope. These findings further confirm serological and structural heterogeneity of O antigens of Proteus strains isolated lately from patients in Poland.

Proteus mirabilis RMS 203 as a new representative of the O13 Proteus serogroup.

The unique feature of some Proteus O-polysaccharides is occurrence of an amide of galacturonic acid with N(ε)-[(S/R)-1-Carboxyethyl]-L-lysine, GalA6(2S,8S/R-AlaLys). The results of the serological studies presented here, with reference to known O-antigens structures suggest that GalA6(2S,8S/R-AlaLys) or 2S,8R-AlaLys contribute to cross-reactions of O13 Proteus antisera, and Proteeae LPSs. It was also revealed that the Proteus mirabilis RMS 203 strain can be classified into the O13 serogroup, represented so far by two strains: Proteus mirabilis 26/57 and Proteus vulgaris 8344. The O13 LPS is a serologically important antigen with a fragment common to LPSs of different species in the Proteeae tribe.

Survey of multidrug resistance integrative mobilizable elements SGI1 and PGI1 in Proteus mirabilis in humans and dogs in France, 2010-13.

OBJECTIVES: To characterize MDR genomic islands related to Salmonella genomic island 1 (SGI1) and Proteus genomic island 1 (PGI1) in Proteus mirabilis from human and animal sources in France in light of the previously reported cases. METHODS: A total of 52 and 46 P. mirabilis clinical strains from human and animal sources, respectively, were studied for the period 2010-13. MDR was assessed by antimicrobial susceptibility testing, PCR detection of SGI1 and PGI1 and PCR mapping of the MDR regions. The diversity of the SGI1/PGI1-positive P. mirabilis strains was assessed by PFGE. RESULTS: Twelve P. mirabilis strains (5 humans and 7 dogs) were found to harbour an MDR island related to SGI1 or PGI1. Among them, several SGI1 variants were identified in diverse P. mirabilis genetic backgrounds. The variant SGI1-V, which harbours the ESBL bla VEB-6 gene, was found in closely genetically related human and dog P. mirabilis strains. The recently described PGI1 element was also identified in human and dog strains. Finally, one strain harboured a novel SGI genomic island closely related to SGI1 and SGI2 without an insertion of the MDR region. CONCLUSION: This study reports for the first time, to our knowledge, SGI1-positive and PGI1-positive P. mirabilis strains from dogs in France. The genetic diversity of the strains suggests several independent horizontal acquisitions of these MDR elements. The potential transmission of SGI1/PGI1-positive P. mirabilis strains between animals and humans is of public health concern, notably with regard to the spread of ESBL and carbapenemase genes, i.e. bla VEB-6 and bla NDM-1.