Genetics of Acquired Antibiotic Resistance Genes in Proteus spp

Detection of OXA-23-producing Proteus mirabilis in Switzerland

Proteus mirabilis is a Gram-negative bacterium found in the environment and also forms part of the commensal flora in the gastrointestinal tract of both humans and animals. P. mirabilis can cause a wide variety of infections, however it does not harbor any intrinsic β-lactamase genes and as such usually exhibits full susceptibility to β-lactams with the exception of imipenem, to which it is naturally resistant. OXA-23 enzymes are carbapenem-hydrolyzing class D β-lactamases and are usually the main cause of acquired resistance to carbapenems in Acinetobacter baumannii but have recently been reported in P. mirabilis in France. In this report we describe the emergence of OXA-23-producing P. mirabilis clinical isolates from Switzerland.

Unraveling the genome of Proteus mirabilis strain representing the O78 serogroup: Insights into the unique features of the O-antigen biosynthesis gene cluster

Lipopolysaccharide (LPS), the outermost component of Gram-negative bacterial cells, is critical to bacterial pathogenicity, functioning as an endotoxin that activates the human immune system and induces an inflammatory response during infection. LPS comprises three primary components: lipid A, the oligosaccharide core, and the O-antigen. The O-antigen, in particular, is highly variable and strain-specific, playing a pivotal role in how the host immune system recognizes bacterial cells. This study focuses on the Proteus mirabilis 1B-m strain, belonging to serogroup O78, the most prevalent serogroup in hospitals in Lodz, Poland. Given the increasing hospitalization rates, particularly among the elderly and catheterized patients, understanding the common strains and their virulence factors is crucial. This work presents bioinformatics analyses based on next-generation sequencing data (both short and long reads), aimed at elucidating the structure of the gene cluster responsible for O-antigen biosynthesis in the 1B-m strain. Our results suggest the presence of a unique wzx flippase in the strain, alongside the characterization of role of the licD gene, which was most often assigned a role in the phosphocholine decoration process of LPS. The function of licD in this strain appears to be linked to the ispD gene, potentially involved in the biosynthesis of CDP-ribitol. Additionally, we explored other genomic features, including the strain's genetic similarity to closely related microorganisms, the presence of antimicrobial resistance genes, and prophage elements. This study provides valuable insights into the genetic factors underlying the pathogenicity of the P. mirabilis 1B-m strain and its potential implications for hospital-acquired infections.

The Detection of Extensively Drug-Resistant Proteus mirabilis Strains Harboring Both VIM-4 and VIM-75 Metallo-β-Lactamases from Patients in Germany

Proteus mirabilis is a well-known opportunistic pathogen predominantly associated with urinary tract infections. It exhibits natural resistance to multiple antibiotics, including last-resort options like colistin. The emergence and spread of multidrug-resistant P. mirabilis isolates, including those producing ESBLs, AmpC cephalosporinases, and carbapenemases, are now more frequently reported. The most common carbapenemase types found in P. mirabilis are KPC-2, IMP, VIM, NDM, and OXA-48. We sequenced the genomes of three carbapenem-resistant P. mirabilis isolates harboring both blaVIM-4 and blaVIM-75 from Germany using both short-read and long-read sequencing techniques. We found that the isolates were only distantly related genetically. Both blaVIM-4 and blaVIM-75 genes were located on a class I integron, which in two cases was located on the chromosome and in one case on a plasmid. This is the first report on the complete genomes of P. mirabilis strains harboring a rare genetic element encoding both blaVIM-4 and blaVIM-75. Our results emphasize a key role for class 1 integrons in the transmission of VIM carbapenemases in P. mirabilis.

Characterisation of Proteus mirabilis isolates from the poultry production chain in Zhejiang Province, China: antimicrobial resistance, virulence factors and genotypic profiling

1. This study investigated antimicrobial resistance, virulence factors and genotypic profiling among Proteus mirabilis isolated from three sources (poultry farms, slaughterhouses and retail markets) in the poultry production chain in Zhejiang Province, China, to assess its potential risk to public health.2. A total of 112 P. mirabilis strains were isolated from 409 samples, including 35 from poultry farms, 35 from slaughterhouses and 42 from retail markets. Antimicrobial susceptibility was tested using 18 antimicrobials in 9 categories, in which 110 (98.2%) strains were considered multidrug-resistant (MDR). These strains carried numerous antimicrobial resistance genes, with the sulphonamide resistance gene (sul1) having the highest rate (100%) and the polymyxin resistance gene (mcr-1) the lowest (3.6%).3. These isolates were validated to carry virulence genes pmfA, mrpA, atfC, rsbA, atfA, ureC and ucaA with the high prevalence of 96.4, 92.9, 92.0, 85.7, 85.7, 57.1 and 46.4%, respectively. Genotyping results using the ERIC-PCR indicated that the genetic similarity of all the isolates was 68.6% to 100% which fell into 4 clusters.4. The P. mirabilis isolates from the slaughterhouses exhibited higher levels of antibiotic resistance and a more pronounced MDR phenomenon than those from poultry farms and retail markets. The proportion of isolates carrying the most commonly detected resistant and virulence genes was higher in samples from poultry farms and slaughterhouses as opposed to retail markets. Importantly, there was genetic similarity and heterogeneity among P. mirabilis isolates from the three sources and genotypic diversity was the highest among isolates from retail markets, followed by slaughterhouses and poultry farms.

Prevalence and characterization of IncQ1α-mediated multi-drug resistance in Proteus mirabilis Isolated from pigs in Kunming, Yunnan, China

Background

Proteus mirabilis is a conditionally pathogenic bacterium that is inherently resistant to polymyxin and tigecycline, largely due to antibiotic resistance genes (ARGs). These ARGs can be horizontally transferred to other bacteria, raising concerns about the Inc plasmid-mediated ARG transmission from Proteus mirabilis, which poses a serious public health threat. This study aims to investigate the presence of Inc plasmid types in pig-derived Proteus mirabilis in Kunming, Yunnan, China.

Methods

Fecal samples were collected from pig farms across six districts of Kunming (Luquan, Jinning, Yiliang, Anning, Songming, and Xundian) from 2022 to 2023. Proteus mirabilis isolates were identified using IDS and 16S rRNA gene sequencing. Then, positive strains underwent antimicrobial susceptibility testing and incompatibility plasmid typing. Multi-drug-resistant isolates with positive incompatibility plasmid genes were selected for whole-genome sequencing. Resistance and Inc group data were then isolated and compared with 126 complete genome sequences from public databases. Whole-genome multi-locus sequence typing, resistance group analysis, genomic island prediction, and plasmid structural gene analysis were performed.

Results

A total of 30 isolates were obtained from 230 samples, yielding a prevalence of 13.04%. All isolates exhibited multi-drug resistance, with 100% resistance to cotrimoxazole, erythromycin, penicillin G, chloramphenicol, ampicillin, and streptomycin. Among these, 15 isolates tested positive for the IncQ1α plasmid repC gene. The two most multi-drug-resistant and repC-positive strains, NO. 15 and 21, were sequenced to compare genomic features on Inc groups and ARGs with public data. Genome analysis revealed that the repC gene was primarily associated with IncQ1α, with structural genes from other F-type plasmids (TraV, TraU, TraN, TraL, TraK, TraI, TraH, TraG, TraF, TraE/GumN, and TraA) also present. Strain NO. 15 carried 33 ARGs, and strain NO. 21 carried 38 ARGs, conferring resistance to tetracyclines, fluoroquinolones, aminoglycosides, sulfonamides, peptides, chloramphenicol, cephalosporins, lincomycins, macrolides, and 2-aminopyrimidines.

Conclusion

The repC gene is primarily associated with IncQ1α, with structural genes from other F-type plasmids. A comparison with 126 public genome datasets confirmed this association.

The SOS Response Activation and the Risk of Antibiotic Resistance Enhancement in Proteus spp. Strains Exposed to Subinhibitory Concentrations of Ciprofloxacin

The widespread and inappropriate use of antibiotics, for therapeutic and prophylactic purposes, has contributed to a global crisis of rapidly increasing antimicrobial resistance of microorganisms. This resistance is often associated with elevated mutagenesis induced by the presence of antibiotics. Additionally, subinhibitory concentrations of antibiotics can trigger stress responses in bacteria, further exacerbating this problem. In the present study, we investigated the effect of low doses of ciprofloxacin on the induction of the SOS response and the subsequent development of antibiotic resistance in Proteus spp. strains. Our findings revealed an increase in mutation frequencies within the studied strains, accompanied by a significant upregulation of recA expression. These observations were consistent across experiments involving two subinhibitory concentrations of ciprofloxacin. To establish mutation frequencies and assess gene expression changes, we utilized the RifS-to-RifR forward mutagenesis assay and RT-qPCR analysis, respectively. Furthermore, employing the microdilution method, we demonstrated that these changes could promote cross-resistance to multiple classes of antibiotics in Proteus spp. clinical strains. This, combined with the recurrent nature of Proteus-associated infections, poses a substantial risk of therapeutic failure. In conclusion, exposure to low doses of ciprofloxacin can significantly impact the susceptibility of Proteus bacilli, not only reducing their sensitivity to ciprofloxacin itself but also fostering resistance to other antibiotic classes. These findings underscore the importance of cautious antibiotic use and highlight the potential consequences of subinhibitory antibiotic exposure in clinical and environmental settings.

Structural and Serological Characterization of Yet Another New O Antigen, O86, in Proteus mirabilis Clinical Strains

Bacteria from the genus Proteus are facultative human pathogens, primarily attacking the urinary tract and wounds. A total of 85 O serogroups have been identified so far among these bacilli. P. mirabilis Bprz 86 was isolated from the fistula of a patient in Łódź, Poland. Enzyme-Linked Immunosorbent Assay (ELISA) and Western blotting studies involving the P. mirabilis Bprz 86 lipopolysaccharide (LPS) and the strain-specific rabbit antiserum indicated that the strain, which does not belong to any of the O1-O85 serogroups, shares a common epitope with Proteus O17 antigens and is identical to another clinical P. mirabilis strain, Sm 120, isolated from the urine of a patient in the area. The O-specific polysaccharide (O antigen) was obtained from P. mirabilis Bprz 86 LPS through mild acid degradation, and the six-constituent structure of its repeating unit was determined using chemical analyses and 1D and 2D 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopy. It includes (R)-3-hydroxybutanoyl, which, along with fucosamine and glucose residues, forms a fragment also present in the O17 antigens. Based on the obtained serological and chemical data, the two studied P. mirabilis isolates were proposed as candidates for a new successive O serogroup in the genus Proteus, O86.

Two multidrug-resistant Proteus mirabilis clones carrying extended spectrum beta-lactamases revealed in a single hospital department by whole genome sequencing

Proteus mirabilis bacteria is a component of normal intestinal microflora of humans and animals, but can also be found in hospital settings causing urinary tract infections and sepsis. The problem of treating such infections is complicated by multidrug-resistant isolates producing extended spectrum beta-lactamases (ESBL), and the number of ESBL-carrying P. mirabilis strains has significantly increased recently. This study presents a detailed analysis of 12 multidrug-resistant P. mirabilis isolates obtained from the wounds of different patients in one surgical department of a multidisciplinary hospital in Moscow, Russia, using the short- and long-read whole genome sequencing. The isolates under investigation divided into two clusters (clones) C1 and C2 based on their genomic profiles and carried antimicrobial resistance (AMR) genes corresponding well with phenotypic profiles, which was the first case of reporting two different P. mirabilis clones obtained simultaneously from the same specimens at one hospital, to the best of our knowledge. Some genes, including ESBL encoding ones, were specific for either C1 or C2 (aac(6')-Ib10, ant(2″)-Ia, qnrA1, bla VEB-6 and fosA3, bla CTX -M-65 , correspondingly). Additionally, the Salmonella genomic islands 1 were found that differed in composition of multiple antibiotic resistance regions between C1 and C2 groups. CRISPR-Cas system type I-E was revealed only in C2 isolates, while the same set of virulence factors was determined for both P. mirabilis clones. Diversity of all genetic factors found in case of simultaneous existence of two clones collected from the same source at one department indicates high pathogenic potential of P. mirabilis and poses a requirement of proper spreading monitoring. The data obtained will facilitate the understanding of AMR transfer and dynamics within clinical P. mirabilis isolates and contribute to epidemiological surveillance of this pathogen.

Antimicrobial Resistance Profiling of Pathogens from Cooked Donkey Meat Products in Beijing Area in One Health Context

The prevalence of foodborne diseases has raised concerns due to the potential transmission of zoonotic bacterial pathogens through meat products. The objective of this study was to determine the occurrence and antimicrobial resistance (AMR) profiles of pathogenic bacteria in cooked donkey meat products from Beijing. Twenty-one cooked donkey meat samples were collected from different delis, subjected to homogenization, and analyzed for bacterial contamination. Molecular identification was performed through polymerase chain reaction (PCR) amplification and sequencing targeting the 16S rDNA gene. The antimicrobial susceptibility of the isolates was evaluated using the disk diffusion method. A total of forty bacterial isolates were identified, with Proteus mirabilis being the predominant species, followed by Klebsiella pneumoniae and Novosphingobium. Both Proteus mirabilis and Klebsiella pneumoniae exhibited high levels of resistance to several antibiotics, including penicillin, ampicillin, and erythromycin. This study's findings underscore the public health risk posed by antimicrobial-resistant foodborne pathogens and emphasize the necessity for enhanced food safety surveillance within the One Health context.

An In Silico Multi-epitopes Vaccine Ensemble and Characterization Against Nosocomial Proteus penneri

Proteus penneri (P. penneri) is a bacillus-shaped, gram-negative, facultative anaerobe bacterium that is primarily an invasive pathogen and the etiological agent of several hospital-associated infections. P. penneri strains are naturally resistant to macrolides, amoxicillin, oxacillin, penicillin G, and cephalosporins; in addition, no vaccines are available against these strains. This warrants efforts to propose a theoretical based multi-epitope vaccine construct to prevent pathogen infections. In this research, reverse vaccinology bioinformatics and immunoinformatics approaches were adopted for vaccine target identification and construction of a multi-epitope vaccine. In the first phase, a core proteome dataset of the targeted pathogen was obtained using the NCBI database and subjected to bacterial pan-genome analysis using bacterial pan-genome analysis (BPGA) to predict core protein sequences which were then used to find good vaccine target candidates. This identified two proteins, Hcp family type VI secretion system effector and superoxide dismutase family protein, as promising vaccine targets. Afterward using the IEDB database, different B-cell and T-cell epitopes were predicted. A set of four epitopes "KGSVNVQDRE, NTGKLTGTR, IIHSDSWNER, and KDGKPVPALK" were chosen for the development of a multi-epitope vaccine construct. A 183 amino acid long vaccine design was built along with "EAAAK" and "GPGPG" linkers and a cholera toxin B-subunit adjuvant. The designed vaccine model comprised immunodominant, non-toxic, non-allergenic, and physicochemical stable epitopes. The model vaccine was docked with MHC-I, MHC-II, and TLR-4 immune cell receptors using the Cluspro2.0 web server. The binding energy score of the vaccine was - 654.7 kcal/mol for MHC-I, - 738.4 kcal/mol for MHC-II, and - 695.0 kcal/mol for TLR-4. A molecular dynamic simulation was done using AMBER v20 package for dynamic behavior in nanoseconds. Additionally, MM-PBSA binding free energy analysis was done to test intermolecular binding interactions between docked molecules. The MM-GBSA net binding energy score was - 148.00 kcal/mol, - 118.00 kcal/mol, and - 127.00 kcal/mol for vaccine with TLR-4, MHC-I, and MHC-II, respectively. Overall, these in silico-based predictions indicated that the vaccine is highly promising in terms of developing protective immunity against P. penneri. However, additional experimental validation is required to unveil the real immune response to the designed vaccine.

OXA-48-like carbapenemases in Proteus mirabilis - novel genetic environments and a challenge for detection

OXA-48-like enzymes represent the most frequently detected carbapenemases in Enterobacterales in Western Europe, North Africa and the Middle East. In contrast to other species, the presence of OXA-48-like in Proteus mirabilis leads to an unusually susceptible phenotype with low MICs for carbapenems and piperacillin-tazobactam, which is easily missed in the diagnostic laboratory. So far, there is little data available on the genetic environments of the corresponding genes, blaOXA-48-like, in P. mirabilis. In this study susceptibility phenotypes and genomic data of 13 OXA-48-like-producing P. mirabilis were investigated (OXA-48, n = 9; OXA-181, n = 3; OXA-162, n = 1). Ten isolates were susceptible to meropenem and ertapenem and three isolates were susceptible to piperacillin-tazobactam. The gene blaOXA-48 was chromosomally located in 7/9 isolates. Thereof, in three isolates blaOXA-48 was inserted into a P. mirabilis genomic island. Of the three isolates harbouring blaOXA-181 one was located on an IncX3 plasmid and two were located on a novel MOBF plasmid, pOXA-P12, within the new transposon Tn7713. In 5/6 isolates with plasmidic location of blaOXA-48-like, the plasmids could conjugate to E. coli recipients in vitro. Vice versa, blaOXA-48-carrying plasmids could conjugate from other Enterobacterales into a P. mirabilis recipient. These data show a high diversity of blaOXA-48-like genetic environments compared to other Enterobacterales, where genetic environments are quite homogenous. Given the difficult-to-detect phenotype of OXA-48-like-producing P. mirabilis and the location of blaOXA-48-like on mobile genetic elements, it is likely that OXA-48-like-producing P. mirabilis can disseminate, escape most surveillance systems, and contribute to a hidden spread of OXA-48-like.

Development of bacterial resistance in Germany from 2008 to 2022 - major culprit pathogens, antibacterial drugs, and prescribing practices

Rising bacterial resistance is a global threat, causing rising financial burdens on healthcare systems and endangering effective treatment of bacterial infections. To ensure the efficacy of antibacterial drugs, it is essential to identify the most dangerous pathogens and vulnerable antibacterial drugs. Previous research by our group suggested irrational outpatient prescribing practices in Germany, supporting a growing bacterial resistance. This study analyses developments and characteristics for the ten most prescribed antibacterial drugs in Germany from 2008 to 2022. Conclusions are based on the development of bacterial resistance levels and an analysis of correlations between pathogens. We identified cefuroxime axetil, sulfamethoxazole-trimethoprim and nitrofurantoin as the most problematic drugs. Particularly problematic pathogens include E. faecalis, E. faecium, K. pneumoniae, and P. mirabilis. Besides increasing bacterial resistance, they are characterised by a high proportion of significant positive correlations, indicating a high potential for mutually reinforcing resistance development. Alarmingly, most of the antibacterial drugs analysed showed a growing resistance to at least one of the analysed pathogens. In most cases, the best treatment option is threatened by increasing bacterial resistance. We also identified several differences between current bacterial resistance data and therapeutic guidelines. In aggregate, our findings support irrational prescribing behaviour and underscore the urgent need for improved prescribing practices to counter rising bacterial resistance in Germany. Moreover, therapeutic guidelines for bacterial infections, the "holy grail" of pharmacotherapy, must be updated more frequently.

Proteus faecis: a potentially pathogenic bacterium isolated from the freshwater Yangtze finless porpoise

Proteus faecis is a gram-negative facultative anaerobic rod-shaped bacterium capable of swarming motility. It has been isolated from numerous sources such as humans, animals, and refuse and is considered potentially pathogenic towards humans. In this study, bacteria were isolated from the blowhole of a Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis; YFP) living in captivity in China. One bacterium, P. faecis porpoise, was isolated and whole genome sequencing done. Biofilm formation, motility and antimicrobial resistance were also investigated. To find putative virulence factors, the genome of P. faecis strain porpoise was compared to the genomic sequences of eight other P. faecis isolates using the Bacterial and Viral Bioinformatics Resource Center (BV-BRC) ( https://www.bv-brc.org/ ). The goal of this study was to initially characterize the pathogenicity of this bacterium isolated from a cetacean species using both pathogenomics and conventional approaches.

Genomic profiling of pan-drug resistant proteus mirabilis Isolates reveals antimicrobial resistance and virulence gene landscape

Proteus mirabilis is a gram-negative pathogen that caused significant opportunistic infections. In this study we aimed to identify antimicrobial resistance (AMR) genes and virulence determinants in two pan-drug resistant isolate "Bacteria_11" and "Bacteria_27" using whole genome sequencing. Proteus mirabilis "Bacteria_11" and "Bacteria_27" were isolated from two different hospitalized patients in Egypt. Antimicrobial susceptibility determined using Vitek 2 system, then whole genome sequencing (WGS) using MinION nanopore sequencing was done. Antimicrobial resistant genes and virulence determinants were identified using ResFinder, CADR AMR database, Abricate tool and VF analyzer were used respectively. Multiple sequence alignment was performed using MAFFT and FastTree, respectively. All genes were present within bacterial chromosome and no plasmid was detected. "Bacteria_11" and "Bacteria_27" had sizes of approximately 4,128,657 bp and 4,120,646 bp respectively, with GC content of 39.15% and 39.09%. "Bacteria_11" and "Bacteria_27" harbored 43 and 42 antimicrobial resistance genes respectively with different resistance mechanisms, and up to 55 and 59 virulence genes respectively. Different resistance mechanisms were identified: antibiotic inactivation, antibiotic efflux, antibiotic target replacement, and antibiotic target change. We identified several genes associated with aminoglycoside resistance, sulfonamide resistance. trimethoprim resistance tetracycline resistance proteins. Also, those responsible for chloramphenicol resistance. For beta-lactam resistance, only blaVEB and blaCMY-2 genes were detected. Genome analysis revealed several virulence factors contribution in isolates pathogenicity and bacterial adaptation. As well as numerous typical secretion systems (TSSs) were present in the two isolates, including T6SS and T3SS. Whole genome sequencing of both isolates identify their genetic context of antimicrobial resistant genes and virulence determinants. This genomic analysis offers detailed representation of resistant mechanisms. Also, it clarifies P. mirabilis ability to acquire resistance and highlights the emergence of extensive drug resistant (XDR) and pan-drug resistant (PDR) strains. This may help in choosing the most appropriate antibiotic treatment and limiting broad spectrum antibiotic use.

Emergence of extensive drug resistance and high prevalence of multidrug resistance among clinical Proteus mirabilis isolates in Egypt

BACKGROUND

Proteus mirabilis is an opportunistic pathogen that has been held responsible for numerous nosocomial and community-acquired infections which are difficult to be controlled because of its diverse antimicrobial resistance mechanisms.

METHODS

Antimicrobial susceptibility patterns of P. mirabilis isolates collected from different clinical sources in Mansoura University Hospitals, Egypt was determined. Moreover, the underlying resistance mechanisms and genetic relatedness between isolates were investigated.

RESULTS

Antimicrobial susceptibility testing indicated elevated levels of resistance to different classes of antimicrobials among the tested P. mirabilis clinical isolates (n = 66). ERIC-PCR showed great diversity among the tested isolates. Six isolates (9.1%) were XDR while all the remaining isolates were MDR. ESBLs and AmpCs were detected in 57.6% and 21.2% of the isolates, respectively, where blaTEM, blaSHV, blaCTX-M, blaCIT-M and blaAmpC were detected. Carbapenemases and MBLs were detected in 10.6 and 9.1% of the isolates, respectively, where blaOXA-48 and blaNDM-1 genes were detected. Quinolone resistant isolates (75.8%) harbored acc(6')-Ib-cr, qnrD, qnrA, and qnrS genes. Resistance to aminoglycosides, trimethoprim-sulfamethoxazole and chloramphenicol exceeded 80%. Fosfomycin was the most active drug against the tested isolates as only 22.7% were resistant. Class I or II integrons were detected in 86.4% of the isolates. Among class I integron positive isolates, four different gene cassette arrays (dfrA17- aadA5, aadB-aadA2, aadA2-lnuF, and dfrA14-arr-3-blaOXA-10-aadA15) and two gene cassettes (dfrA7 and aadA1) were detected. While class II integron positive isolates carried four different gene cassette arrays (dfrA1-sat1-aadA1, estXVr-sat2-aadA1, lnuF- dfrA1-aadA1, and dfrA1-sat2).

CONCLUSION

P. Mirabilis ability to acquire resistance determinants via integrons may be held responsible for the elevated rates of antimicrobial resistance and emergence of XDR or even PDR strains limiting the available therapeutic options for management of infections caused by those strains.

Assessing the antibacterial potential of 6-gingerol: Combined experimental and computational approaches

The rise of antibiotic resistance in bacteria is becoming a global concern, particularly due to the dwindling supply of new antibiotics. This situation mandates the discovery of new antimicrobial candidates. Plant-derived natural compounds have historically played a crucial role in the development of antibiotics, serving as a rich source of substances possessing antimicrobial properties. Numerous studies have supported the reputation of 6-gingerol, a prominent compound found in the ginger family, for its antibacterial properties. In this study, the antibacterial activities of 6-gingerol were evaluated against Gram-negative bacteria, Acinetobacter baumannii and Klebsiella pneumoniae, with a particular focus on the clinically significant Gram-negative Pseudomonas aeruginosa and Gram-positive bacteria Staphylococcus aureus. Furthermore, the anti-virulence activities were assessed in vitro, in vivo, and in silico. The current findings showed that 6-gingerol's antibacterial activity is due to its significant effect on the disruption of the bacterial cell membrane and efflux pumps, as it significantly decreased the efflux and disrupted the cell membrane of S. aureus and P. aeruginosa. Furthermore, 6-gingerol significantly decreased the biofilm formation and production of virulence factors in S. aureus and P. aeruginosa in concentrations below MICs. The anti-virulence properties of 6-gingerol could be attributed to its capacity to disrupt bacterial virulence-regulating systems; quorum sensing (QS). 6-Gingerol was found to interact with QS receptors and downregulate the genes responsible for QS. In addition, molecular docking, and molecular dynamics (MD) simulation results indicated that 6-gingerol showed a comparable binding affinity to the co-crystalized ligands of different P. aeruginosa QS targets as well as stable interactions during 100 ns MD simulations. These findings suggest that 6-gingerol holds promise as an anti-virulence agent that can be combined with antibiotics for the treatment of severe infections.

Predictive statistical models for monitoring antimicrobial resistance spread in the environment using Apis mellifera (L. 1758) colonies

The rise of antimicrobial resistance (AMR) is one of the most relevant problems for human and animal health. According to One Health Approach, it is important to regulate the use of antimicrobials and monitor the spread of AMR in the environment as well. Apis mellifera (L. 1758) colonies were used as bioindicators thanks to their physical and behavioural characteristics. During their foraging flights, bees can intercept small particles, including atmospheric particulate matter, etc., and also microorganisms. To date, the antimicrobial surveillance network is limited to the sanitary level but lacks into environmental context. This study aimed to evaluate the use of A. mellifera colonies distributed throughout the Emilia-Romagna region (Italy) as indicators of environmental antimicrobial-resistant bacteria. This was performed by creating a statistical predictive model that establishes correlations between environmental characteristics and the likelihood of isolating specific bacterial genera and antimicrobial-resistant strains. A total of 608 strains were isolated and tested for susceptibility to 19 different antimicrobials. Aztreonam-resistant strains were significantly related to environments with sanitary structures, agricultural areas and wetlands, while urban areas present a higher probability of trimethoprim/sulfamethoxazole-resistant strains isolation. Concerning genera, environments with sanitary structures and wetlands are significantly related to the genera Proteus spp., while the Escherichia spp. strains can be probably isolated in industrial environments. The obtained models showed maximum values of Models Accuracy and robustness (R2) of 55 % and 24 %, respectively. The results indicate the efficacy of utilizing A. mellifera colonies as valuable bioindicators for estimating the prevalence of AMR in environmentally disseminated bacteria. This survey can be considered a good basis for the development of further studies focused on monitoring both sanitary and animal pathology, creating a specific network in the environments of interest.

Overview of Proteus mirabilis pathogenicity and virulence. Insights into the role of metals

Proteus mirabilis is a Gram-negative bacterium with exclusive molecular and biological features. It is a versatile pathogen acclaimed for its distinct urease production, swarming behavior, and rapid multicellular activity. Clinically, P. mirabilis is a frequent pathogen of the human urinary system where it causes urinary tract infections (UTIs) and catheter-associated urinary tract infections (CAUTIs). This review explores the epidemiology, risk factors, clinical manifestations, and treatment of P. mirabilis infections, emphasizing its association with UTIs. The bacterium's genome analysis revealed the presence of resistance genes against commonly used antibiotics, an antibiotic-resistant phenotype that poses a serious clinical challenge. Particularly, the emergence of extended-spectrum β-lactamases (ESBLs) and carbapenemases resistant P. mirabilis strains. On a molecular level, P. mirabilis possesses a wide array of virulence factors including the production of fimbriae, urease, hemolysins, metallophores, and biofilm formation. This review thoroughly tackles a substantial gap in understanding the role of metallophores in shaping the virulence factors of P. mirabilis virulence. Siderophores, iron metal chelating and transporting metallophores, particularly contribute to the complex pathogenic strategies, displaying a potential target for therapeutic intervention.

Antibiotic resistance and virulence profiles of Proteus mirabilis isolated from broiler chickens at abattoir in South Africa

BACKGROUND

Proteus mirabilis has been identified as an important zoonotic pathogen, causing several illnesses such as diarrhoea, keratitis and urinary tract infections.

OBJECTIVE

This study assessed the prevalence of P. mirabilis in broiler chickens, its antibiotic resistance (AR) patterns, ESBL-producing P. mirabilis and the presence of virulence genes.

METHODS

A total of 26 isolates were confirmed as P. mirabilis from 480 pooled broiler chicken faecal samples by polymerase chain reaction (PCR). The disk diffusion method was used to evaluate the antibacterial susceptibility test, while nine virulence genes and 26 AR genes were also screened by PCR.

RESULTS

All 26 P. mirabilis isolates harboured the ireA (siderophore receptors), ptA, and zapA (proteases), ucaA, pmfA, atfA, and mrpA (fimbriae), hlyA and hpmA (haemolysins) virulence genes. The P. mirabilis isolates were resistant to ciprofloxacin (62%) and levofloxacin (54%), while 8 (30.7%) of the isolates were classified as multidrug resistant (MDR). PCR analysis identified the blaCTX-M gene (62%), blaTEM (58%) and blaCTX-M-2 (38%). Further screening for AMR genes identified mcr-1, cat1, cat2, qnrA, qnrD and mecA, 12%, 19%, 12%, 54%, 27% and 8%, respectively for P. mirabilis isolates. The prevalence of the integron integrase intI1 and intI2 genes was 43% and 4%, respectively.

CONCLUSIONS

The rise of ciprofloxacin and levofloxacin resistance, as well as MDR strains, is a public health threat that points to a challenge in the treatment of infections caused by these zoonotic bacteria. Furthermore, because ESBL-producing P. mirabilis has the potential to spread to humans, the presence of blaCTX -M -producing P. mirabilis in broilers should be kept under control. This is the first study undertaken to isolate P. mirabilis from chicken faecal samples and investigate its antibiotic resistance status as well as virulence profiles in South Africa.

Prevalence of drug resistant Enterobacteriaceae in a Nepalese tertiary care hospital

Antimicrobial resistance in Enterobacteriaceae is an emerging global public health problem. Numerous studies have reported community-acquired AmpC beta-lactamase and extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae in Nepal. However, there are limited data on community-acquired Metallo-beta-lactamase (MBL) producing Enterobacteriaceae. A hospital-based descriptive cross-sectional study was conducted using 294 Enterobacteriaceae isolates from a total of 2,345 different clinical specimens collected from patients attending a tertiary care hospital in Nepal. Bacteria were isolated using standard microbiological growth media and identified using biochemical tests. For antimicrobial susceptibility testing, Kirby-Bauer disc diffusion technique was used. AmpC, ESBL, and MBL productions were detected by using combined disc method. AmpC, ESBL, and MBL productions were detected in 19.4%, 29.6%, and 8.5% of total Enterobacteriaceae isolates respectively. Higher rates of beta-lactamases production were seen among the isolates from in-patients in comparison with those from out-patients. However, 11.6%, 25%, and 3.7% of the total isolates from out-patients were AmpC, ESBL, and MBL producers respectively. The co-production of the beta-lactamases was also detected, with two Klebsiella pneumoniae isolates producing all three beta-lactamases. One MBL producing Proteus vulgaris isolate that was pan-resistant with no remaining treatment options was also isolated. Prevalence of drug resistant Enterobacteriaceae in our study was very high. Detection of AmpC, ESBL, and MBL positive isolates from out-patients, who did not have recent history of hospital visit, indicated the community dissemination of the drug resistant bacteria. This is a matter of great concern and an immediate attention to formulate strategies to prevent further development and spread of antibiotic resistance is required.

First Report of Complete Genome Analysis of Multiple Drug Resistance Proteus mirabilis KUST‐1312 Isolate From Migratory Birds in China: A Public Health Threat

Proteus mirabilis, a gram‐negative bacterium, poses a significant public health threat due to its multidrug‐resistant (MDR) characteristics. Here, for the first time, we report the isolation and comprehensive genome analysis of an MDR strain, P. mirabilis KUST‐1312, obtained from migratory birds in Yunnan Province, China. A total of 65 samples, including migratory bird feces, soil, and water from Dianchi Lake, were collected. Standard microbiological techniques were employed to isolate the P. mirabilis KUST‐1312 strain from these samples. Genomic sequencing was conducted using a hybrid assembly strategy, combining Illumina and Oxford nanopore sequencing technologies. Phenotypic testing revealed the MDR nature of P. mirabilis KUST‐1312, displaying resistance to various antibiotics except gentamicin and Cefotaxime. Notably, 15 antimicrobial resistance genes (ARGs), including aph(3′)‐Ia, cat, tet(J), bleO, dfrA12, aadA2, AAC(3)‐IId, bla-TEM-1B, erm(42),aph(6)‐Id, blaPER-1, sul2, aph(3′’)‐Ib(2copies), and aph(3′)‐VIb, were identified on a single chromosome. These 15 ARGs were dispersed along three MDR regions, and the boundaries of these regions were consistently flanked by copies of insertion sequences and also contained other genetic elements. Phylogenetic analysis revealed the close relation of P. mirabilis KUST‐1312 with environmental and clinical isolates reported from other continents rather than with Asian isolates. In conclusion, this study reports the first‐ever isolation of an MDR P. mirabilis KUST‐1312 strain from migratory birds globally, particularly in China. There is a need to explore further its prevalence in detail in various ecological niches, including migratory birds.

Computational study to investigate Proteus mirabilis proteomes for multi-epitope vaccine construct design

Proteus mirabilis is a gram-negative bacterium particularly known for its unique swarming ability. The swarming gives the bacteria ability to enhance adherence to the catheter surface and epithelium cells of the urethra to cause catheter associated urinary tract infections. P. mirabilis has evolved resistant to antibiotics. Additionally, there is an approved vaccine against P. mirabilis, thus demanding for identification of new vaccine targets. This gram-negative bacterium consists of 19,502 core proteins, out of which 19,063 are redundant proteins and remaining 439 are non-redundant proteins. The non-redundant proteins have 21 proteins present on the cell surface out of which 11 proteins are virulent. Antigenicity analysis predicted only 2 proteins as antigenic (fimbrial biogenesis outer membrane usher protein and ligand-gated channel protein). Four and seven B-cells epitopes were predicted from the former and later proteins, respectively. The predicted B-cells epitopes were used for T- cells epitopes prediction. The predicted epitopes were linked to each other through GPGPG linkers and joined with cholera toxin beta subunit adjuvant. A multi-epitopes vaccine construct consisting of 226 residues was docked with MHC-I, MHC-II and TLR-4. The best docked complex in each case has binding energy of -714.6, -744.6 and -829.5 kcal/mol, respectively. Moreover, the docking results were validated through molecular dynamics simulation and binding free energies estimation. The net energy of -137.2 kcal/mol was calculated for vaccine-MHC-I complex, -133.39 kcal/mol for vaccine-MHC-II and -158.68 kcal/mol for vaccine-TLR-4 complex. The designed vaccine construct could provoke immune responses against targeted pathogen and may be used in experimental testing.Communicated by Ramaswamy H. Sarma.

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

OBJECTIVES

To analyse carbapenemases in Proteus mirabilis and assess the performance of carbapenemase detection assays.

METHODS

Eighty-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.

RESULTS

Carbapenemases 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.

DISCUSSION

Current 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.

Evaluation of Different Activity of Lactobacillus spp. against Two Proteus mirabilis Isolated Clinical Strains in Different Anatomical Sites In Vitro: An Explorative Study to Improve the Therapeutic Approach

Urinary tract infections (UTIs) and catheter-associated UTIs (CAUTIs) are the principal hospital-acquired infections. Between these, bacterial prostatitis is believed to be the leading cause of recurrent UTIs in men under 50 years of age and is often unresponsive to antibiotic treatment. Proteus mirabilis is more commonly associated with UTIs in these abnormalities, especially in patients undergoing catheterization. Lactobacillus spp. are an important component of the human microbiota and occur in large quantities in foods. Probiotics are proposed as an alternative to antibiotic therapy in the treatment of urinary tract infections. In addition to their ability to produce antimicrobial metabolites, they have immunomodulatory activity and do not cause side effects. For this reason, the combination of probiotic microorganisms and conventional drugs was considered. The aim of this work was to select the most active Lactobacillus strains against two clinical isolates of P. mirabilis on bladder and prostatic epithelium, potentially exploitable to improve the clinical management of UTIs.

Isolation and Characterization of the Acadevirus Members BigMira and MidiMira Infecting a Highly Pathogenic Proteus mirabilis Strain

Proteus mirabilis is an opportunistic pathogen and is responsible for more than 40% of all cases of catheter-associated urinary tract infections (CAUTIs). Healthcare-associated infections have been aggravated by the constant emergence of antibiotic-resistant bacterial strains. Because of this, the use of phages to combat bacterial infections gained renewed interest. In this study, we describe the biological and genomic features of two P. mirabilis phages, named BigMira and MidiMira. These phages belong to the Acadevirus genus (family Autographiviridae). BigMira and MidiMira are highly similar, differing only in four missense mutations in their phage tail fiber. These mutations are sufficient to impact the phages' depolymerase activity. Subsequently, the comparative genomic analysis of ten clinical P. mirabilis strains revealed differences in their antibiotic resistance profiles and lipopolysaccharide locus, with the latter potentially explaining the host range data of the phages. The massive presence of antimicrobial resistance genes, especially in the phages' isolation strain P. mirabilis MCS, highlights the challenges in treating infections caused by multidrug-resistant bacteria. The findings reinforce BigMira and MidiMira phages as candidates for phage therapy purposes.

Genetic analysis of resistance and virulence characteristics of clinical multidrug-resistant Proteus mirabilis isolates

Objective

Proteus mirabilis is the one of most important pathogens of catheter-associated urinary tract infections. The emergence of multidrug-resistant (MDR) P. mirabilis severely limits antibiotic treatments, which poses a public health risk. This study aims to investigate the resistance characteristics and virulence potential for a collection of P. mirabilis clinical isolates.

Methods and results

Antibiotic susceptibility testing revealed fourteen MDR strains, which showed high resistance to most β-lactams and trimethoprim/sulfamethoxazole, and a lesser extent to quinolones. All the MDR strains were sensitive to carbapenems (except imipenem), ceftazidime, and amikacin, and most of them were also sensitive to aminoglycosides. The obtained MDR isolates were sequenced using an Illumina HiSeq. The core genome-based phylogenetic tree reveals the high genetic diversity of these MDR P. mirabilis isolates and highlights the possibility of clonal spread of them across China. Mobile genetic elements SXT/R391 ICEs were commonly (10/14) detected in these MDR P. mirabilis strains, whereas the presence of resistance island PmGRI1 and plasmid was sporadic. All ICEs except for ICEPmiChn31006 carried abundant antimicrobial resistance genes (ARGs) in the HS4 region, including the extended-spectrum β-lactamase (ESBL) gene blaCTX-M-65. ICEPmiChn31006 contained the sole ARG blaCMY-2 and was nearly identical to the global epidemic ICEPmiJpn1. The findings highlight the important roles of ICEs in mediating the spread of ARGs in P. mirabilis strains. Additionally, these MDR P. mirabilis strains have great virulence potential as they exhibited significant virulence-related phenotypes including strong crystalline biofilm, hemolysis, urease production, and robust swarming motility, and harbored abundant virulence genes.

Conclusion

In conclusion, the prevalence of MDR P. mirabilis with high virulence potential poses an urgent threat to public health. Intensive monitoring is needed to reduce the incidence of infections by MDR P. mirabilis.

A subclass of the IS1202 family of bacterial insertion sequences targets XerCD recombination sites

We describe here a new family of IS which are related to IS1202, originally isolated from Streptococcus pneumoniae in the mid-1990s and previously tagged as an emerging IS family in the ISfinder database. Members of this family have impacted some important properties of their hosts. We describe here another potentially important property of certain family members: specific targeting of xrs recombination sites. The family could be divided into three subgroups based on their transposase sequences and the length on the target repeats (DR) they generate on insertion: subgroup IS1202 (24-29 bp); ISTde1 (15-18 bp); and ISAba32 (5-6 bp). Members of the ISAba32 subgroup were repeatedly found abutting Xer recombinase recombination sites (xrs), separated by an intervening copy of a DR. These xrs sites, present in multiple copies in a number of Acinetobacter plasmids flanking antibiotic resistance genes, were proposed to form a new type of mobile genetic element using the chromosomally-encoded XerCD recombinase for mobility. Transposase alignments identified subgroup-specific indels which may be responsible for the differences in the transposition properties of the three subgroups (i.e. DR length and target specificity). We propose that this collection of IS be classed as a new insertion sequence family: the IS1202 family composed of three subgroups, only one of which specifically targets plasmid-borne xrs. We discuss the implications of xrs targeting for gene mobility.

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

Introduction

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).

Method

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.

Results

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, bla_CTX-M, bla_CTX-M-2, bla_OXA-1, bla_TEM, 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: bla_TEM, bla_CTX-M, and bla_CTX-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.

Discussion

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.

Whole genome sequencing of multidrug-resistant Proteus mirabilis strain PM1162 recovered from a urinary tract infection in China

OBJECTIVES

Proteus mirabilis is an important opportunistic Gram-negative pathogen. This study reports the whole genome sequence of multidrug-resistant (MDR) P. mirabilis PM1162 and explores its antibiotic resistance genes (ARGs) and their genetic environments.

METHODS

P. mirabilis PM1162 was isolated from a urinary tract infection in China. Antimicrobial susceptibility was determined, and whole genome sequencing (WGS) was performed. ARGs, insertion sequence (IS) elements, and prophages were identified using ResFinder, ISfinder, and PHASTER software, respectively. Sequence comparisons and map generation were performed using BLAST and Easyfig, respectively.

RESULTS

On its chromosome, P. mirabilis PM1162 harboured 15 ARGs, including cat, tet(J), bla_CTX-M-14 (three copies), aph(3')-Ia, qnrB4, bla_DHA-1, qacE, sul1, armA, msr(E), mph(E), aadA1, and dfrA1. We focused our analysis on the four related MDR regions: (1) genetic contexts associated with bla_CTX-M-14; (2) the prophage containing bla_DHA-1, qnrB4, and aph(3')-Ia; (3) genetic environments associated with mph(E), msr(E), armA, sul, and qacE; and (4) the class II integron harbouring dfrA1, sat2, and aadA1.

CONCLUSION

This study reported the whole genome sequence of MDR P. mirabilis PM1162 and the genetic context of its ARGs. This comprehensive genomic analysis of MDR P. mirabilis PM1162 provides a deeper understanding of its MDR mechanism and elucidates the horizontal spread of its ARGs, thus providing a basis for the containment and treatment of the bacteria.

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 bla_OXA-1, bla_CTX-M-1G, bla_CTX-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

Background and Aim: 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. Materials and Methods: 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. Results: 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) or extensively 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. Conclusion: 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.

The transmittable through stinging microbiota differs between honeybees and wasps: a potentially greater microbial risk of the wasp sting for humans

The present research investigated whether accidental contact through stinging with honeybees, wasps, and hornets could represent a microbial hazard for humans. It has been previously suggested that such contact may transmit pathogens causing infections that could even be fatal for some susceptible individuals. Stinging simulation experiments were performed in the lab with live insects collected from the environment in Lemnos Island (north-eastern Greece), while different selective agar media targeting some clinically important bacteria (i.e., Staphylococcus aureus, Streptococcus pyogenes, Enterococcus faecalis/faecium, and Pseudomonas aeruginosa) were used as substrates for microbial recovery and identification. Results revealed none of the target pathogenic bacterial species in the honeybee samples, with bacilli, staphylococci, and micrococci dominating their surveyed microbiota. However, most of the suspect colonies isolated from wasps and hornets belonged to important hygienic indicators (i.e., enterococci, Proteus mirabilis, and coliforms), implying possible contact of these insects with fecal origin materials. To sum up, the microbiota that may be transmitted to humans through stinging appears to differ between honeybees and wasps/hornets, while the isolation from the latter samples of some other important opportunistic pathogens, such as Enterobacter spp. and Klebsiella spp., also known for multidrug resistance, could be an additional reason of concern.

Proteus mirabilis isolated from untreated hospital wastewater, Ibadan, Southwestern Nigeria showed low-level resistance to fluoroquinolone and carried qnrD3 on Col3M plasmids

Untreated wastewater emanating from healthcare facilities are risk factors for the spread of antimicrobial resistance (AMR) at the human-environment interface. In this study, we investigated the determinants of resistance in three multidrug resistant strains of Proteus mirabilis isolated from untreated wastewater collected from three government owned hospitals in Ibadan, Nigeria. Despite showing low-level resistance to ciprofloxacin, whole genome sequencing revealed the transferable mechanism of quinolone resistance (TMQR) gene qnrD3 carried on Col3M plasmids in all the isolates. Core genome phylogenetic analysis showed the isolates are closely related differing from each other by ≤ 23 single nucleotide polymorphisms (SNP). Further, they shared the closest evolutionary relationship with isolates from China. Similarly, the Col3M plasmids is most closely related to p3M-2A found in P. vulgaris 3 M isolated from the intestine of shrimps in China. This to the best of our knowledge is the first report of Col3M plasmids carrying qnrD3 in environmental bacterial isolates. Our results indicate a possible silent spread of this important plasmid associated with the dissemination of qnrD3 in Nigeria, and further highlights the important role played by untreated wastewater from healthcare facilities in the spread of AMR in low- and middle-income countries.

Metabolomic Profiling, Antibacterial, and Molluscicidal Properties of the Medicinal Plants Calotropis procera and Atriplex halimus: In Silico Molecular Docking Study

The potential of plant-based natural compounds in the creation of new molluscicidal and antimicrobial medications has gained attention in recent years. The current study compared the metabolic profiles, antibacterial, and molluscicidal properties of the medicinal plants Calotropis procera (C. procera) and Atriplex halimus (A. halimus). In both plants, 118 metabolites were identified using gas chromatography-mass spectrometry. Palmitic acid, stigmasterol, and campesterol were the most prevalent constituents. C. procera extract showed stronger antibacterial activity than A. halimus against Escherichia coli and Proteus mirabilis. Both extracts exhibited molluscicidal activity against Biomphalaria alexandrina, with LC₅₀ values of C. procera (135 mg/L) and A. halimus (223.8 mg/L). Survival rates of snails exposed to sub-lethal concentrations (LC₂₅) of C. procera and A. halimus extracts were 5% and 20%, respectively. The hatchability of snail eggs exposed to both extracts has been dramatically reduced. Both extracts significantly decreased the levels of alkaline phosphatase, acid phosphatase, total protein, and albumin in snails, as well as causing DNA damage and resulting in numerous hermaphrodite and digestive gland damages and distortions. Molecular docking showed palmitic acid binding with acid, alkaline, and alanine aminotransferases in treated digestive gland snails. In conclusion, C. procera and A. halimus have antibacterial and molluscicidal properties.

Temporal dynamic of antibiotic resistance genes in the Zaohe-Weihe hyporheic zone: driven by oxygen and bacterial community

The widespread spread of antibiotic resistance genes (ARGs) in hyporheic zone (HZ) has become an emerging environmental problem due to their potentially harmful nature. In this research, three different oxygen treatment systems were set up to study the effects of oxygen changes on the abundance of ARGs in the HZ. In addition, the effects of temperature and salinity on ARGs were investigated under aerobic and anaerobic systems, respectively. The bacterial community composition of sediment samples and the relationship with ARGs were analyzed. The explanation ratio and causality of the driving factors affecting ARGs were analyzed using variation partitioning analysis (VPA) and structural equation model (SEM). The relative abundance of ARGs and mobile genetic elements (MGEs) in the anaerobic system increased significantly, which was higher than that in the aerobic system and the aerobic-anaerobic interaction system. The experiment of salinity and temperature also further proved this result. There were many bacterial communities that affected tetracycline and sulfonamide ARGs in sediments, and these host bacteria are mainly concentrated in Proteobacteria, Firmicutes and Bacteroidetes. VPA and SEM further revealed that the abundance of ARGs was mainly influenced by changes in bacterial communities and oxygen conditions, and horizontal gene transfer (HGT) of MGEs also had a positive effect on the spread of ARGs. Those findings suggest that complex oxygen conditions in the HZ alter bacterial communities and promote MGEs-mediated horizontal transfer, which together lead to the spread of ARGs. This study has value as a reference for formulating effective strategies to minimize the propagation of ARGs in underground environment.

Study of the molecular characteristics and homology of carbapenem-resistant Proteus mirabilis by whole genome sequencing

Introduction. Proteus mirabilis is part of the family Enterobacteriaceae, and is naturally resistant to various antimicrobial drugs. In recent years, outbreaks of severe nosocomial infections caused by carbapenem-resistant P. mirabilis (CR-PMI) have been frequently reported. Few studies exist on the whole-genome molecular characteristics of this bacterium in China and elsewhere, which stimulated the implementation of this study.Hypothesis. CR-PMI strains contained the multiple drug resistance genes and exhibited a high resistance rate to commonly used antimicrobial drugs.Aim. Our goals here were to identify resistance mechanisms and homology of CR-PMI strains and provide a theoretical basis for clinical treatment and controlling nosocomial infections.Methodology. Bacterial species identification was carried out using matrix-assisted laser desorption/ionization time of flight MS (MALDI-TOF-MS). Antimicrobial susceptibility was determined using the VITEK 2 system and Kirby-Bauer (K-B) disc-diffusion method. Whole-genome sequencing (WGS) was conducted by the Illumina platform NovaSeq sequencer. Antibiotic resistance genes (ARGs) were identified using the NCBI database with Abricate. Plasmid replicon types were identified using PlasmidFinder, available at the Center for Genomic Epidemiology.Results. Five CR-PMI strains collected in our hospital from July 2019 to September 2021 were resistant to almost all antimicrobial agents except aztreonam (ATM), amikacin (AMK) and cefotetan (CTT). All CR-PMI strains contained the carbapenem resistance gene New Delhi metallo-β-lactamase 1 (bla _NDM-1), and two strains harboured extended-spectrum β-lactamase (ESBL) genes bla _PER-4 and bla _CTX-M-65. The five CR-PMI strains contained 27, 18, 30, 25 and 24 drug-resistance genes, respectively. Most antimicrobial resistance genes were detected for aminoglycosides (n=14), followed by cephalosporins (n=7). The phylogenetic tree was divided into five evolutionary groups, and the five CR-PMI strains were in the four evolutionary groups B-E.Conclusion Overall, CR-PMI strains exhibited a high resistance rate to commonly used antimicrobial drugs, and contained the carbapenem resistance gene bla _NDM-1. The CR-PMI strains showed a polyclonal trend in different wards at different times. Most importantly, all strains identified contained important antimicrobial resistance genes, which may lead to severe drug resistance transmission and fatal multiple resistant bacterial infections.

Contamination of Proteus mirabilis harbouring various clinically important antimicrobial resistance genes in retail meat and aquatic products from food markets in China

Proteus mirabilis is an opportunistic pathogen frequently associated with nosocomial infection and food poisoning cases. Contamination of P. mirabilis in retail meat products may be important transmission routes for human infection with P. mirabilis. In this study a total of 89 P. mirabilis strains were isolated from 347 samples in 14 food markets in China and subjected to whole-genome sequencing. Phylogenetic analysis showed that all 89 strains were divided into 81 different clones (SNPs >5), indicating high genetic diversity of P. mirabilis in food markets. Antimicrobial susceptibility testing showed that 81 (91.01%) strains displayed multidrug resistance profiles. Seventy-three different resistance genes (or variants) were found, including various clinically important antimicrobial resistance genes aac(6')-Ib-cr (77.53%), bla _CTX-M (39.33%), fosA3 (30.34%), as well as multiresistance gene cfr (4.50%), tigecycline resistance gene cluster tmexCD3-toprJ1 (4.50%) and carbapenemase gene bla _NDM-1 (1.12%). Diverse genetic elements including Tn7 transposon, plasmid, SXT/R391 integrative conjugative element were associated with the horizontal transfer of cfr. tmexCD3-toprJ1 and bla _NDM-1 were located on ICEPmiChnJZ26 and Salmonella genomic island 1, respectively. Our study emphasized high contamination of P. mirabilis harbouring various clinically important antimicrobial resistance genes in retail meat and aquatic products, which might be an important issue in terms of food safety and human health.

Prevalence of multidrug-resistant Gram-negative bacteria from blood cultures and rapid detection of beta-lactamase-encoding genes by multiplex PCR assay

Introduction

This study aimed to determine the prevalence of multidrug-resistant Gram-negative bacteria (GNB) from blood cultures in a tertiary-care hospital and the multiplex PCR assay's ability to detect resistance genes.

Methods

A total of 388 GNB isolates obtained from hospitalized patients between November 2019 and November 2021 were included in the study. Antimicrobial susceptibility testing was done by VITEK 2 system and broth microdilution method. Beta-lactamase-encoding genes were detected by multiplex PCR assays, BioFire-Blood Culture Identification 2 (BCID2) panel (bioMérieux, France). Extended-spectrum beta-lactamases (ESBLs) were detected phenotypically with VITEK AST-GN71 card (bioMérieux, France). The isolates of GNB were classified into multidrug-resistant, extensively-drug-resistant, and pandrug-resistant categories, and their prevalence and distribution in different wards, including coronavirus diseases 2019 (COVID-19) intensive care units (ICU), were calculated.

Results

Results revealed that all isolates of Acinetobacter baumannii and Pseudomonas aeruginosa were multidrug-resistant as well as 91.6% of Enterobacter cloacae, 80.6% of Proteus mirabilis, and 76.1% of Klebsiella pneumoniae, respectively. In fermentative bacteria, blaOXA-48-like (58.1%), blaNDM (16.1%), blaKPC (9.7%) and blaVIM (6.5%) genes were detected. More than half of Enterobacter cloacae (58.3%) and Klebsiella pneumoniae (53.7%) produced ESBLs. Among non-fermenters, the blaNDM gene was carried by 55% of Pseudomonas aeruginosa and 19.5% of Acinetobacter baumannii. In the COVID-19 ICU, Acinetobacter baumannii was the most common isolate (86.1%).

Conclusions

This study revealed high proportions of multidrug-resistant blood isolates and various underlying resistance genes in Gram-negative strains. The BCID2 panel seems to be helpful for the detection of the most prevalent resistance genes of fermentative bacteria.

Ibrahim T, Khafagy ES, Lopes BS, Ali MAM, Hegazy WAH, Elfaky MA. Characterization of the Anti-Biofilm and Anti-Quorum Sensing Activities of the β-Adrenoreceptor Antagonist Atenolol against Gram-Negative Bacterial Pathogens

The development of bacterial resistance to antibiotics is an increasing public health issue that worsens with the formation of biofilms. Quorum sensing (QS) orchestrates the bacterial virulence and controls the formation of biofilm. Targeting bacterial virulence is promising approach to overcome the resistance increment to antibiotics. In a previous detailed in silico study, the anti-QS activities of twenty-two β-adrenoreceptor blockers were screened supposing atenolol as a promising candidate. The current study aims to evaluate the anti-QS, anti-biofilm and anti-virulence activities of the β-adrenoreceptor blocker atenolol against Gram-negative bacteria Serratia marcescens, Pseudomonas aeruginosa, and Proteus mirabilis. An in silico study was conducted to evaluate the binding affinity of atenolol to S. marcescens SmaR QS receptor, P. aeruginosa QscR QS receptor, and P. mirabilis MrpH adhesin. The atenolol anti-virulence activity was evaluated against the tested strains in vitro and in vivo. The present finding shows considerable ability of atenolol to compete with QS proteins and significantly downregulated the expression of QS- and virulence-encoding genes. Atenolol showed significant reduction in the tested bacterial biofilm formation, virulence enzyme production, and motility. Furthermore, atenolol significantly diminished the bacterial capacity for killing and protected mice. In conclusion, atenolol has potential anti-QS and anti-virulence activities against S. marcescens, P. aeruginosa, and P. mirabilis and can be used as an adjuvant in treatment of aggressive bacterial infections.

Identification of iron-responsive genes in Proteus vulgaris

Iron is essential for almost all bacteria, and iron homeostasis is precisely controlled by the ferric uptake regulator (Fur). The Fur regulons have been well characterized in some model bacteria, yet little is known in the common opportunistic pathogen Proteus vulgaris. In this study, Fur regulon and iron-responsive genes in P. vulgaris were mainly defined by in silico and proteomic analyses. The results showed that about 250 potential Fur-regulated operons including 14 transcriptional factors were predicted, while 559 proteins exhibited differential expression in response to iron deficiency, not all being directly regulated by Fur, such as transcriptional factors lexA, recA, narL, and arcA. Collectively, these results demonstrated that Fur functioned as a global regulatory protein to repress or activate expression of a large repertoire of genes in P. vulgaris; besides, not all the iron-responsive genes were directly regulated by Fur, whereas indirectly regulated through other mechanisms such as additional transcriptional regulatory proteins.

Muting Bacterial Communication: Evaluation of Prazosin Anti-Quorum Sensing Activities against Gram-Negative Bacteria Pseudomonas aeruginosa, Proteus mirabilis, and Serratia marcescens

Simple Summary

Bacterial infections are considered one of the main challenges to global health. Bacterial virulence is controlled by interplayed systems to regulate bacterial invasion and infection in host tissues. Quorum sensing (QS) plays a crucial role in regulating virulence factor production, thus could be considered as the bacterial communication system in the bacterial population. The current study aimed to assess the anti-QS and anti-virulence activities of α-adrenoreceptor prazosin against three virulent Gram-negative bacteria. It was demonstrated that prazosin significantly downregulates the expression of QS-encoding genes and shows considered ability to compete on QS proteins in tested strains. Prazosin can significantly diminish biofilm formation and production of virulent enzymes and mitigate the virulence factors of tested strains. However, more testing is required alongside pharmacological and toxicological studies to assure the potential clinical use of prazosin as an adjuvant anti-QS and anti-virulence agent.

Abstract

Quorum sensing (QS) controls the production of several bacterial virulence factors. There is accumulative evidence to support that targeting QS can ensure a significant diminishing of bacterial virulence. Lessening bacterial virulence has been approved as an efficient strategy to overcome the development of antimicrobial resistance. The current study aimed to assess the anti-QS and anti-virulence activities of α-adrenoreceptor prazosin against three virulent Gram-negative bacteria Pseudomonades aeruginosa, Proteus mirabilis, and Serratia marcescens. The evaluation of anti-QS was carried out on a series of in vitro experiments, while the anti-virulence activities of prazosin were tested in an in vivo animal model. The prazosin anti-QS activity was assessed on the production of QS-controlled Chromobacterium violaceum pigment violacein and the expression of QS-encoding genes in P. aeruginosa. In vitro tests were performed to evaluate the prazosin effects on biofilm formation and production of extracellular enzymes by P. aeruginosa, P. mirabilis, and S. marcescens. A protective assay was conducted to evaluate the in vivo anti-virulence activity of prazosin against P. aeruginosa, P. mirabilis, and S. marcescens. Moreover, precise in silico molecular docking was performed to test the prazosin affinity to different QS receptors. The results revealed that prazosin significantly decreased the production of violacein and the virulent enzymes, protease and hemolysins, in the tested strains. Prazosin significantly diminished biofilm formation in vitro and bacterial virulence in vivo. The prazosin anti-QS activity was proven by its downregulation of QS-encoding genes and its obvious binding affinity to QS receptors. In conclusion, prazosin could be considered an efficient anti-virulence agent to be used as an adjuvant to antibiotics, however, it requires further pharmacological evaluations prior to clinical application.

Antibiotic Resistance in Proteus mirabilis: Mechanism, Status, and Public Health Significance

Proteus mirabilis is a specific opportunistic pathogen of many infections including urinary tract infections (UTIs). Risk factors are linked with the acquisition of multidrug-resistant (MDR) to 3 or more classes of antimicrobials) strains. The resistance in extended-spectrum alpha-lactamase is rare, but the rising resistance in extended-spectrum beta-lactamase (ESBL) producing strains is a matter of concern. β-lactamases and antibiotic modifying enzymes mainly constitute the ESBLs resistance mechanism by hydrolyzing the antibiotics. Mutation or Porin loss could lead to the reduced permeability of antibiotics, enhanced efflux pump activity hindering the antibiotic access to the target site, antibiotic failure to bind at the target site because of the target modification, and lipopolysaccharide mutation causing the resistance against polymyxin antibiotics. This review aimed to explore various antimicrobial resistance mechanisms in Proteus mirabilis and their impact on public health status.

Isolation and Characterization of Lytic Proteus Virus 309

Proteus mirabilis is frequently associated with complicated urinary tract infections (UTIs) and is the main cause of catheter-associated urinary tract infections (CAUTIs). Treatment of such infections is complicated and challenging due to the biofilm forming abilities of P. mirabilis. If neglected or mistreated, infections may lead to life-threating conditions such as cystitis, pyelonephritis, kidney failure, and bacteremia that may progress to urosepsis. Treatment with antibiotics, especially in cases of recurring and persistent infections, leads to the development of resistant strains. Recent insights into phage therapy and using phages to coat catheters have been evaluated with many studies showing promising results. Here, we describe a highly lytic bacteriophage, Proteus_virus_309 (41,740 bp), isolated from a wastewater treatment facility in Cape Town, South Africa. According to guidelines of the International Committee on Taxonomy of Viruses (ICTV), bacteriophage 309 is a species within the genus Novosibovirus. Similar to most members of the genus, bacteriophage 309 is strain-specific and lyse P. mirabilis in less than 20 min.

Patterns of Antibiotic Resistance in Enterobacteriaceae Isolates from Broiler Chicken in the West Region of Cameroon: A Cross-Sectional Study

Background. The emergence of multidrug-resistant food-borne pathogens of animal origin including Enterobacteriaceae is a growing concern. Identifying and monitoring resistance in isolates from human-related environments are of clinical and epidemiological significance in containing antimicrobial resistance. This study aimed to contribute towards the fight against antibiotic resistance and ameliorate the management/treatment of Enterobacteriaceae-linked diseases in Cameroon. Methods. Cloacal swabs from healthy broilers were enriched in buffered-peptone-water and cultured on EMB agar. Antibiotic susceptibility was tested on Mueller-Hinton-Agar by disc diffusion. Plasmid-borne genes for extended-spectrum beta lactamase (ESBL) and resistance to Quinolones (PMQR) and Aminoglycosides were detected by standard endpoint polymerase chain reaction (PCR). Results. A total of 394 isolates were identified belonging to 12 Enterobacteriaceae genera, the most prevalent were Escherichia coli (81/394 = 20.56%), Salmonella spp (74/394 = 18.78%), and Klebsiella spp (39/394 = 9.90%) respectively. Overall, 84/394 (21.32%) were ESBL producers, 164/394 (41.62%) were resistant to quinolones, 66/394 (16.75%) resistant to aminoglycosides with 44.0% (173/394) expressing MDR phenotype. Poor hygiene practice (OR 2.55, 95% CI: 1.67, 3.89, $p=0.001$ ) and rearing for >45 days, (OR = 7.98, 95% CI: 5.05, 12.6, $p=0.001$ ) were associated with increased carriage of MDR. Plasmid-borne resistance genes were detected in 76/84 (90.48%) of ESBL-producing isolates, 151/164 (92.07%) quinolone resistant isolates and 59/66 (89.39%) aminoglycoside resistant isolates with co-occurrence of two or more genes per isolate in 58/84 (69.05%) of ESBLs, 132/164 (80.49%) of quinolone resistant isolates and 28/66 (42.42%) of aminoglycoside resistant isolates. Conclusion. This study found high carriage and widespread distribution of Enterobacteriaceae with ESBL and MDR in broiler chicken in the West Region of Cameroon. Most PMQR genes in bacteria were found at levels higher than is seen elsewhere, representing a risk in the wider human community.

Sialic Acid Derivatives Inhibit SiaT Transporters and Delay Bacterial Growth

Antibiotic resistance is a major worldwide concern, and new drugs with mechanistically novel modes of action are urgently needed. Here, we report the structure-based drug design, synthesis, and evaluation in vitro and in cellular systems of sialic acid derivatives able to inhibit the bacterial sialic acid symporter SiaT. We designed and synthesized 21 sialic acid derivatives and screened their affinity for SiaT by a thermal shift assay and elucidated the inhibitory mechanism through binding thermodynamics, computational methods, and inhibitory kinetic studies. The most potent compounds, which have a 180-fold higher affinity compared to the natural substrate, were tested in bacterial growth assays and indicate bacterial growth delay in methicillin-resistant Staphylococcus aureus. This study represents the first example and a promising lead in developing sialic acid uptake inhibitors as novel antibacterial agents.

Case Report: An Ulceration With a Stalactite Appearance on the Index Finger

Proteus mirabilis, the most widespread species of all Proteus spp. bacteria, is proven to be one of the most universal pathogens in chronic wounds. In this case, a woman in her 40s consulted a physician about an asymptomatic ulceration with a stalactite appearance at the distal end of the index finger after she was exposed to a needle when vaccinating chickens. The patient did not response to ceftazidime. Physical examination revealed a well-demarcated violescent ulceration with a stalactite appearance at the distal end of the index finger. A biopsy of the lesion showed dense infiltration of multinucleated giant cells, histiocytes, and lymphocytes in the dermis. The result of metagenomics next-generation sequencing (NGS) showed 306 unique sequence reads of P. mirabilis, covering 33.49% of the nucleotide sequences. The pathogen was identified as P. mirabilis, which was resistant to ceftazidime. The patient was treated with ciprofloxacin hydrochloride and improved considerably. This case reported a distinctive cutaneous lesion of P. mirabilis on human infection and showed a successful use of NGS in P. mirabilis.

Detection of Carbapenem Resistance of Proteus mirabilis Strains Isolated from Foxes, Raccoons and Minks in China

Proteus mirabilis, an opportunistic pathogen, is found to be an emerging threat to both animals and humans for a variety of infections. However, the characteristics of P. mirabilis infections from foxes, raccoons and minks remain unclear. In this context, we identified the antibiotic resistance genes and virulence genes of P. mirabilis isolates from foxes, raccoons and minks in China. Most isolates showed resistance to florfenicol (90.57%), trimethoprim-sulfamethoxazole (73.58%), and imipenem (71.70%). A total of 73.58% of isolates were resistant to antibiotics from at least three or more classes, and were categorized as multi-drug resistant. A total of 33.33% of the isolates were resistant to antibiotics from seven classes. The most prevalent resistant were sul1 (94.34%), followed by floR, blaTEM, aac(6’)Ib-cr and blaOXA-1 with the detection rate of 88.68%, 83.02%, 71.70% and 60.38%, respectively. Among the 51 P. mirabilis isolates that were resistant to beta-lactam antibiotics, all isolates carried at least one beta-lactam gene. In addition, blaNDM and blaOXA-24 genes were firstly reported in carbapenem-resistant P. mirabilis isolates from foxes, raccoons and minks. All isolates exhibited the virulence genes ureC, zapA, pmfA, atfA and mrpA. P. mirabilis isolates carrying all detected 10 virulence genes from different animal species showed different lethal abilities in a G. mellonella larvae model. More importantly, the profiles of antibiotic resistance genes of isolates from fur animals and the environment were generally similar, and phylogenetic analysis showed that the P. mirabilis isolates from farm environment samples may have close relatedness with that from animals.