Virulence, resistance and clonality of Proteus mirabilis isolated from patients with community-acquired urinary tract infection (CA-UTI) in Brazil

A Novel Proteus-Specific, Piezoelectric Sensor Based on Newly Screened Targets

Proteus spp. are conditionally pathogenic bacteria that cause urinary tract infections, gastrointestinal diseases, and food poisoning. Accurate and rapid detection of Proteus is crucial in medical diagnosis and food safety. In the present study, a new 16S rRNA sequence fragment was identified as a Proteus detection target. A novel Proteus piezoelectric sensor was constructed based on this screened target by combining catalytic hairpin self-assembly target cycle technology, hybrid chain reaction amplification technology, and a piezoelectric sensor. The proposed method was rapid and highly specific; 10-106 CFU/mL Proteus could be detected within 3 h in the presence of Escherichia coli, Staphylococcus aureus, and other common bacteria. The limit of detection was as low as 10 CFU/mL. The proposed method could offer a rapid, sensitive, and specific approach for Proteus detection with broad application potential.

Clonal Dissemination of NDM-Producing Proteus mirabilis in a Teaching Hospital in Sousse, Tunisia

Proteus mirabilis (P. mirabilis) is an opportunistic pathogen involved in urinary tract infections as well as various nosocomial infections. Emerging resistances to beta-lactams in this species complicates potential treatment since it is intrinsically resistant to colistin. Eleven isolates of carbapenem-non-susceptible P. mirabilis were identified in Sousse Hospital, Tunisia, from January 2018 to December 2022. MICs were determined and isolates were sequenced to determine their resistomes, sequence types, virulence factors, and their clonal relationships. Susceptibility testing showed that all isolates were resistant to carbapenems, aminoglycosides, fluoroquinolones, chloramphenicol, and the trimethoprim/sulfamethoxazole combination. They remained susceptible to the aztreonam/avibactam combination. All isolates produced NDM-1 carbapenemase and ArmA 16S rRNA methylase. In addition, one isolate co-produced the blaVEB-6 gene. All isolates belonged to ST135, and phylogenetic analysis revealed that they were closely related. This study described the first outbreak of NDM-1-producing P. mirabilis in Tunisia.

Impact of COVID-19 pandemic on antimicrobial resistance of Proteus mirabilis in a Brazilian hospital

This study analyzes the resistance and virulence profiles of Proteus mirabilis isolates obtained from patients admitted to the University Hospital of Londrina, Paraná, between 2019 and 2022. We evaluated the antimicrobial resistance phenotypes, genes associated with resistance, biofilm formation through a phenotypic assay, and the presence of specific virulence genes. When comparing the "pre-pandemic" (2019) and "pandemic" (2020-2022) periods, we observed an increase in resistance rates to all tested antimicrobials. Multidrug-resistant (MDR) pathogens producing extended-spectrum β-lactamase (ESBL) phenotypes were isolated in both periods, but their occurrence was significantly higher during the pandemic. We also observed an increase in the frequency of nearly all studied resistance genes. The virulence profiles remained largely unchanged. Analysis of patients' clinical and demographic data revealed that those hospitalized during the pandemic were older, required longer hospital stays, and had a higher usage of invasive devices. These findings suggest that the recent COVID-19 pandemic has impacted the antimicrobial resistance of P. mirabilis, a bacterium of significant clinical interest associated with urinary tract infections (UTIs) and healthcare-associated infections (HAIs).

Epidemiological trends and predictions of urinary tract infections in the global burden of disease study 2021

Urinary tract infections (UTIs) are prevalent; however, comprehensive and current epidemiological data remain scarce. This study examined the global, national, and regional burden of UTIs by sex, age, and socio-demographic index (SDI) from 1990 to 2021. The 2021 Global Burden of Disease study included age-standardised incidence rate (ASIR), age-standardised prevalence rate (ASPR), age-standardised death rate (ASDR), and age-standardised disability-adjusted life years rate (ASDAR). The estimated annual percentage change was used to depict temporal trends, whereas Pearson correlation analysis explore its correlation with the human development index (HDI), the SDI, and age-standardised rates (ASRs). An autoregressive integrated moving average model forecasted the UTI burden trends. From 1990 to 2021, the number of UTI cases increased by 66.45%, reaching 4.49 billion cases, with an ASIR of 5,531.88 per 100,000 population. The greatest incidence of UTIs was seen in women and older adult men. Tropical Latin America and low-middle SDI regions exhibited the highest ASIR, ASPR, ASDR, and ASDAR, while East Asia showed the lowest. ASDR and ASDAR decreased with higher SDI levels. ASR and HDI were weakly positively correlated with ASDR and ASDAR. ASIR, ASPR, and ASDAR are projected to increase until 2050. The global burden of UTIs is rising and is influenced by geographical location, age, sex, and economic development, crucial for guiding medical practices and forming relevant policies.

Assessment of typing methods, virulence genes profile and antimicrobial susceptibility for clinical isolates of Proteus mirabilis

Proteus mirabilis (P. mirabilis) is one of the most important causative pathogens associated with complicated urinary tract infections with a 20% incidence. For epidemiological determinations, several phenotypic and molecular typing methods have been implicated. Sixty P. mirabilis isolated undergo antibiotic susceptibility test by standard Kirby Bauer method. They showed high resistance to nitrofurantoin and trimethoprim/sulfamethoxazole that appear mainly in 3rd age group. The 2nd age group comprised most of the resistant isolates to the tested antibiotics. A total of 73.33% of isolates were classified as multi drug resistance (MDR) and 78.3% of isolates were distributed in several antibiotypes with MAR index over 0.2. Twenty-one isolates were strong biofilm-producers and they were significantly related to MDR. Different virulence factors as protease, urease and hemolysin production are detected. Detection of several virulence genes by PCR; zapA and ureC were harbored by all isolates, followed by rsbA (95%), ureA and flaA (93%), hpmA (91.7%) and mrpA (73.3%). Determination of genetic diversity between isolates was performed by different methods (RAPD, ISSR, ERIC, BOX-AIR and REP-PCR) by using several parameters as typeability and discriminatory power indicating that ERIC-PCR was the best method followed by REP-PCR 1R. Rand's & Wallace coefficients were used for calculating the congruence among typing methods. Conclusions: The results obtained from both conventional and molecular typing methods indicated that molecular methods are superior to conventional methods in the discrimination of isolates. ERIC-PCR and Rep-PCR provide high discrimination ability among P. mirabilis clinical isolates contributing to epidemiological studies.

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.

The incidence, clinical features and outcome of urinary tract infections in geriatric patients: A prospective longitudinal study

Objectives

This study compares the incidence, clinical features, microbial profiles, and outcomes of urinary tract infections (UTIs) in patients aged 65 years and older versus those younger than 65 years.

Methods

A longitudinal cohort of 1,123 patients was divided into Group A (≥65 years, n = 560) and Group B (<65 years, n = 563) and followed for 2 years. The study analyzed UTI incidence, clinical features, microbial profiles, and outcomes, including recurrence and antibiotic resistance.

Results

Over 2 years, Group A had a significantly higher UTI incidence (38.0%) compared with Group B (12.8%) (P <0.0001). Complete recovery was less common in Group A (44.6%) than in Group B (70.83%), whereas recurrent UTIs and antibiotic resistance were more frequent in Group A (43.5% vs 22.2%, P <0.0001 and 11.7% vs 2.78%, P = 0.0017, respectively). Escherichia coli was the most prevalent pathogen in both groups, with Klebsiella and Pseudomonas species more common in recurrent UTIs, particularly in older patients. Risk factors for recurrent UTIs included advanced age, female sex, diabetes, immunosuppression, and renal stones.

Conclusions

These findings highlight the need for age-specific UTI prevention and management strategies that account for microbial resistance patterns and higher recurrence rates in older patients, addressing clinical and microbial challenges.

Comprehensive insights into UTIs: from pathophysiology to precision diagnosis and management

Urinary tract infections (UTIs) are the second most common infectious disease, predominantly impacting women with 150 million individuals affected globally. It increases the socio-economic burden of society and is mainly caused by Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter spp., and Staphylococcus spp. The severity of the infection correlates with the host factors varying from acute to chronic infections. Even with a high incidence rate, the diagnosis is mainly based on the symptoms, dipstick analysis, and culture analysis, which are time-consuming, labour-intensive, and lacking sensitivity and specificity. During this period, medical professionals prescribe empirical antibiotics, which may increase the antimicrobial resistance rate. Timely and precise UTI diagnosis is essential for addressing antibiotic resistance and improving overall quality of life. In response to these challenges, new techniques are emerging. The review provides a comprehensive overview of the global burden of UTIs, associated risk factors, implicated organisms, traditional and innovative diagnostic methods, and approaches to UTI treatment and prevention.

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.

Medical Device-Associated Biofilm Infections and Multidrug-Resistant Pathogens

Medical devices such as venous catheters (VCs) and urinary catheters (UCs) are widely used in the hospital setting. However, the implantation of these devices is often accompanied by complications. About 60 to 70% of nosocomial infections (NIs) are linked to biofilms. The main complication is the ability of microorganisms to adhere to surfaces and form biofilms which protect them and help them to persist in the host. Indeed, by crossing the skin barrier, the insertion of VC inevitably allows skin flora or accidental environmental contaminants to access the underlying tissues and cause fatal complications like bloodstream infections (BSIs). In fact, 80,000 central venous catheters-BSIs (CVC-BSIs)-mainly occur in intensive care units (ICUs) with a death rate of 12 to 25%. Similarly, catheter-associated urinary tract infections (CA-UTIs) are the most commonlyhospital-acquired infections (HAIs) worldwide.These infections represent up to 40% of NIs.In this review, we present a summary of biofilm formation steps. We provide an overview of two main and important infections in clinical settings linked to medical devices, namely the catheter-asociated bloodstream infections (CA-BSIs) and catheter-associated urinary tract infections (CA-UTIs), and highlight also the most multidrug resistant bacteria implicated in these infections. Furthermore, we draw attention toseveral useful prevention strategies, and advanced antimicrobial and antifouling approaches developed to reduce bacterial colonization on catheter surfaces and the incidence of the catheter-related infections.

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.

Clonal relationship, virulence genes, and antimicrobial resistance of Morganella morganii isolated from community-acquired infections and hospitalized patients: a neglected opportunistic pathogen

Morganella morganii is a bacterium belonging to the normal intestinal microbiota and the environment; however, in immunocompromised individuals, this bacterium can become an opportunistic pathogen, causing a series of diseases, both in hospitals and in the community, being urinary tract infections more prevalent. Therefore, the objective of this study was to evaluate the prevalence, virulence profile, and resistance to antimicrobials and the clonal relationship of isolates of urinary tract infections (UTI) caused by M. morganii, both in the hospital environment and in the community of the municipality of Londrina-PR, in southern Brazil, in order to better understand the mechanisms for the establishment of the disease caused by this bacterium. Our study showed that M. morganii presents a variety of virulence factors in the studied isolates. Hospital strains showed a higher prevalence for the virulence genes zapA, iutA, and fimH, while community strains showed a higher prevalence for the ireA and iutA genes. Hospital isolates showed greater resistance compared to community isolates, as well as a higher prevalence of multidrug-resistant (MDR) and extended-spectrum beta lactamase (ESBL)-producing isolates. Several M. morganii isolates from both sources showed high genetic similarity. The most prevalent plasmid incompatibility groups detected were FIB and I1, regardless of the isolation source. Thus, M. morganii isolates can accumulate virulence factors and antimicrobial resistance, making them a neglected opportunistic pathogen.

Prevalence, Resistance Patterns and Biofilm Production Ability of Bacterial Uropathogens from Cases of Community-Acquired Urinary Tract Infections in South Italy

Community-acquired urinary tract infections represent the most common infectious diseases in the community setting. Knowing the antibiotic resistance patterns of uropathogens is crucial for establishing empirical treatment. The aim of the current study is to determine the incidence of the causative agents of UTIs and their resistance profiles. Patients of all ages and both sexes were enrolled in the study, and admitted to San Ciro Diagnostic Center in Naples between January 2019 and Jun 2020. Bacterial identification and antibiotic susceptibility testing were carried out using Vitek 2 system. Among the 2741 urine samples, 1702 (62.1%) and 1309 (37.9%) were negative and positive for bacterial growth, respectively. Of 1309 patients with infection, 760 (73.1%) were females and 279 (26.9%) were males. The greatest number of positive cases were found in the in the elderly (>61 years). Regarding uropathogens, 1000 (96.2%) were Gram-negative while 39 (3.8%) were Gram-positive strains. The three most isolated pathogenic strains were Escherichia coli (72.2%), Klebsiella pneumoniae (12.4%), and Proteus mirabilis (9.0%). Strong biofilm formation ability was observed in about 30% of the tested isolates. The low resistance rates recorded against nitrofurantoin, fosfomycin, piperacillin-tazobactam, and gentamicin could suggest them as the most appropriate therapies for CA-UTIs.

Prevalence of Antimicrobial Resistance and Clonal Relationship in ESBL/AmpC-Producing Proteus mirabilis Isolated from Meat Products and Community-Acquired Urinary Tract Infection (UTI-CA) in Southern Brazil

The present study aimed to evaluate the prevalence of antimicrobial resistance and clonal relationships in Proteus mirabilis isolated from chicken meat, beef, pork, and community-acquired urinary tract infections (UTI-CA). Chicken meat isolates showed the highest multidrug resistance (MDR), followed by those from pork and UTI-CA, whereas beef had relatively few MDR strains. All sources had strains that carried blaCTX-M-65, whereas blaCTX-M-2 and blaCMY-2 were only detected in chicken meat and UTI-CA isolates. This indicates that chicken meat should be considered an important risk factor for the spread of P. mirabilis carrying ESBL and AmpC. Furthermore, ESBL/AmpC producing strains were resistant to a greater number of antimicrobials and possessed more resistance genes than non-producing strains. In addition, the antimicrobial resistance genes qnrD, aac(6')-Ib-cr, sul1, sul2, fosA3, cmlA, and floR were also found. Molecular typing showed a genetic similarity between chicken meat and UTI-CA isolates, including some strains with 100% similarity, indicating that chicken can be a source of P. mirabilis causing UTI-CA. It was concluded that meat, especially chicken meat, can be an important source of dissemination of multidrug-resistant P. mirabilis in the community.

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

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

Drug-Resistant Proteus Virulence Factors Characterization and Their Inhibition Using Probiotic Bacteria

Background: The genus Proteus is a Gram-negative bacterium with a unique characteristic of swarming. Mainly three species are involved in initiating urinary tract infections in the community and in immunocompromised patients, particularly in patients going through long-term catheterization. Due to their strong virulence factors like biofilm formations, protease, and hemolysin, they can lead to lengthening infections in affected individuals. Probiotics are live bacteria and yeasts that are beneficial to human health and can be used as an alternative for the control of nosocomial diseases. Lactobacilli are one of the common probiotics mostly found in yogurt and other fermented foods that have been used as a substitute for infection control. Objectives: The current study was designed to screen potential probiotic bacteria to encounter antibiotic-resistant and virulent Proteus species. Methods: In the current study, using probiotics, already known antibiotic-resistant isolates (n = 25) of Proteus were processed to characterize their virulence factors and their inhibition. Biofilm formation, protease, and hemolysin activities were studied using different phenotypic detection methods. Further, their virulence genes zapA, flg, hmpA, mrp, and rsbA were explored using their genomic DNA. These isolates were found resistant to different classes of antibiotics, and a strategy was designed to inhibit their growth by using probiotic bacteria isolated from the soil. Results: Virulence factors first, all isolates were subjected to biofilm detection, and they were 32% (n = 8) strong, 40% (n = 10) moderate, 16% (n = 4) weak, and 12% (n = 3) non-biofilm producers. All isolates were positive for swarming activity by showing a differentiated ring form of growth. Protease activity showed 56% (n = 14) isolates. Only 24% (n = 6) of isolates were positive for hemolysin. Virulence factors and molecular mechanisms were studied, and gene rsbA responsible for swarming was amplified in 17 (68%) Proteus isolates, and mrp responsible for fimbria was detected in 19 (76%) bacterial isolates. Further, these isolates were subjected to flagella, protease, and hemolysin, and it was revealed that flg 11 (44%), 13 (52%) protease coding zapA, and hmA gene coding hemolysin were amplified in 2 (8%) Proteus isolates. Probiotic bacteria isolated from soil samples were probed for antagonistic activity against Proteus species. The probiotic bacteria were identified as Lactobacillus plantarum, Bacillus subtilis, and B. licheniformis. Due to their strong growth inhibitory effects against Proteus, it is crucial to characterize further the metabolites that have shown suppressive results against Proteus. Conclusions: Findings from the current study will provide new avenues for drug development and also help clinicians manage resistant pathogens in healthcare settings. Probiotic applications for infection control can be useful in treating resistant pathogens. Further purification and characterization of metabolites will provide alternative options for managing resistance issues in microbes.

Antibiotic Sensitivity of Proteus mirabilis Urinary Tract Infection in Patients with Urinary Calculi

BACKGROUND

The study's objective was to determine Proteus mirabilis susceptibility in individuals with urinary tract infections and stones to antibiotics and prescribe optimal antimicrobial treatment.

METHODS

Nonrepetitive Proteus mirabilis strains were isolated from urine specimens obtained from 317 patients diagnosed with urinary stones from January, 2018, to December, 2021. A VITEK mass spectrometer was used for species identification, and a VITEK-compact 2 automatic microbial system was used for the antimicrobial susceptibility test (AST). Susceptibility to imipenem and cefoperazone/sodium sulbactam was tested by the disc diffusion method (K-B method). The antibiotic sensitivity of the strains was analyzed by sex and season.

RESULTS

A total of 317 patients were reviewed: 202 females (63.7%) and 115 males (36.3%). Proteus mirabilis infections were observed during spring (21.8%, n = 69), summer (26.2%, n = 83), autumn (33.8%, n = 107), and winter (18.2%, n = 57). Proteus mirabilis infections in females were diagnosed most often during the fall (24.3%, n = 77) and during the summer in males (11.0%, n = 35) (p = 0.010). Female patients responded best to levofloxacin (p = 0.014), and male patients responded best to sulfamethoxazole (p = 0.023). Seasonal variation in antibiotic sensitivity was confirmed, with significantly higher rates in the winter for cefuroxime (p = 0.002) and sulfamethoxazole (p = 0.002). Significant seasonal increases were also found in levofloxacin sensitivity during the summer (p = 0.005).

CONCLUSIONS

Highly effective antibiotics such as cefoxitin and ceftazidime should be used empirically by considering antibiotic sensitivity changes by sex, season, and year. Regional studies should be conducted frequently.

From the Urinary Catheter to the Prevalence of Three Classes of Integrons, β-Lactamase Genes, and Differences in Antimicrobial Susceptibility of Proteus mirabilis and Clonal Relatedness with Rep-PCR

Introduction

Proteus mirabilis is a biofilm-forming agent that quickly settles on the urinary catheters and causing catheter-associated urinary tract infections. Thus, the spread of multidrug-resistant P. mirabilis isolates, with the ability to form a biofilm that carries integron, extended-spectrum β-lactamases (ESBLs), and plasmid-mediated colistin resistance genes (mcr), represents a severe threat to managing nosocomial infectious diseases. This study is aimed at surveying the prevalence of ESBL, integrase, and mcr genes of P. mirabilis, isolated from the catheter, to assess the differences in their antimicrobial susceptibility and clonal dissemination.

Method

Microtiter plate assay was adopted to measure biofilm formation. The antimicrobial susceptibility was assessed by the disk diffusion method. Antimicrobial resistance genes (intI1, intI2, intI3, bla_TEM, bla_CTX-M, bla_SHV, mcr1, and mcr2) were detected by PCR. All of the isolates were characterized by repetitive sequence-based PCR.

Result

From 385 collected catheters in patients admitted to the intensive care unit (ICU), 40 P. mirabilis were isolated. All of the isolates could form a biofilm. Proteus spp. had intrinsic resistance to tetracycline (95%) and nitrofurantoin (92.5%), which explains the high resistance prevalence. The most widely resistant antibiotic was trimethoprim-sulfamethoxazole (75%). Thirty-three (82.5%) isolates were classified as multidrug resistance (MDR). The prevalence of intI1 and intI2 genes was 60% and 25%, respectively. In 6 (15%) isolates, both genes were detected. The most frequent ESBL gene detected in all of the isolates was bla_TEM. Also, no detection for mcr1 and mcr2 antibiotic resistance genes was reported. Rep-PCR identified 39(GTG)5 types (G1–G39) of 40 isolates that 38 isolates had unique patterns.

Conclusion

In this study, 82.5% of isolates were MDR with high antibiotic resistance to trimethoprim-sulfamethoxazole. The intI1 and bla_TEM were the most prevalent genes in the integrase and ESBL gene family. High diversity was seen in the isolates with Rep-PCR. The increasing rate of MDR isolates with a high prevalence of resistance genes could be alarming and demonstrate the need for hygienic procedures to prevent the increased antibiotic resistance rate in the future.