Increasing relevance of Gram-positive cocci in urinary tract infections: a 10-year analysis of their prevalence and resistance trends

Global status of antimicrobial resistance in clinical Enterococcus faecalis isolates: systematic review and meta-analysis

BACKGROUND

Due to the increasing emergence of antibiotic resistance in Enterococcus faecalis (E. faecalis), it indicated as potentially opportunistic pathogen causing various healthcare-associated and life-threatening diseases around the world.

OBJECTIVE

The aim of this meta-analysis was to evaluate the weighted pooled resistance rates in clinical E. faecalis isolates based on over time, areas, antimicrobial susceptibility testing (AST), and infection source.

METHODS

We searched the studies in PubMed, Scopus, and Web of Science (November 30, 2022). All statistical analyses were carried out using the statistical package R.

RESULTS

The analysis encompassed a total of 74 studies conducted in 28 countries. According to the meta-regression, the chloramphenicol, fosfomycin, imipenem, linezolid, minocycline, norfloxacin, quinupristin-dalfopristin, and tetracycline resistance rate increased over time. Analysis revealed statistically significant differences in antibiotic resistance rates for ampicillin, chloramphenicol, erythromycin, gentamicin, penicillin, rifampicin, teicoplanin, tetracycline, and vancomycin across various countries.

CONCLUSIONS

Globally, the prevalence of drug resistant E. faecalis strains are on the increase over time. Daptomycin and tigecycline can be an effective agent for the treatment of clinical E. faecalis infections. Considering the low prevalence of antibiotic resistance in continents of Europe and Australia, it is suggested to take advantage of their preventive strategies in order to obtain efficient results in other places with high prevalence of resistance.

Linezolid in enterococcal urinary tract infection: a multicentre study

PURPOSE

Few data have been published on the efficacy of linezolid in enterococcal urinary tract infection (e-UTI). The aims of this study were to describe the characteristics of patients with enterococci UTI treated with linezolid, and to evaluate the efficacy and the tolerance of linezolid treatment.

METHODS

An observational multicentre retrospective study was conducted in 5 hospitals in France. Patients were included if they met the following criteria: ≥18 years, clinical and microbiological criteria for enterococcal UTI and linezolid treatment > 48 h. Primary outcome was clinical failure.

RESULTS

Eighty-one patients were included between January 2015 and December 2021. The median age was 73.0 [64; 83] years and 47 (58%) were men. The median Charlson comorbidity index was 3.00 [2; 6]. E. faecium was reported in 65 (80%) cases and E. faecalis in 26 cases (32%). Polymicrobial infections occurred in 41 (51%) cases. No enterococci was resistant to vancomycin. Before linezolid prescription an empiric antimicrobial treatment was started in 48 (59%) cases and was effective against enterococci in 19/48 (39.5%) patients for a median of 3.5 days [2.0; 4.0]. The median duration of linezolid antibiotic treatment was 13 days [10; 14]. Three adverse events were reported, none were serious but one led to discontinuation of treatment. Treatment failure was reported in 2 cases (2.5%).

CONCLUSION

This study provides evidence for efficacy and safety of linezolid in enterococcal UTI.

Chemical composition and bioactivity variability of two-step extracts derived from traditional and "QiNan" agarwood (Aquilaria spp.)

One of the primary applications for agarwood lies in the extracts, instead, there are obvious differences in the demands for agarwood components with different application fields. To obtain the rough separation and clarify each part's activity, four extracts of essential oil, hydrolat, extractum, and ethanol precipitation from traditional agarwood (TraA) and "Qinan" agarwood (QinA) were obtained by steam-solvent multistage extraction and ethanol precipitation. We investigated the chemistry and biological activity of multistage extracts using gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), and in vitro activity testing. The results demonstrated that two kinds of agarwood essential oils contained mainly sesquiterpenoids, yet the sesquiterpene species were remarkably diverse in two kinds of agarwood essential oils. Then, the TraA and QinA hydrolat, all predominantly aromatic and sesquiterpene, but with differences from the essential oil ingredients. Additionally, the extractum chiefly contained chromones and the ethanol precipitation method worked well to separate the impurities in the TraA extract, however, it was ineffective for the QinA extract. Ultimately, essential oils and extractums all have antioxidant properties, with extractums outperforming essential oils. Moreover, both extractums and essential oils exhibited excellent broad-spectrum antimicrobial activity and anti-inflammatory activity. The findings pointed to the feasibility of separating the primary components from TraA and QinA using a multi-stage extraction technique, providing a scientific basis for the efficient utilization of all components of agarwood, as well as the functional product development and differentiated utilization of extract products in incense, fragrance, perfume, and daily chemicals.

The Impact of Polymerase Chain Reaction Urine Testing on Clinical Decision-Making in the Management of Complex Urinary Tract Infections

While urinary polymerase chain reaction (PCR) testing is effective in organism identification in patients with complex urinary tract infections (cUTI), limited data exists on the clinical usefulness of this test. We serially surveyed physicians treating symptomatic patients with cUTI both at presentation and after PCR, and urine culture (UC) results were available to ascertain how the test results modified the therapy. A total of 96 unique surveys completed by 21 providers were included in the data analysis. The mean age for female and male patients was 69.4 ± 15.5 and 71.6 ± 12.7 years, respectively. The test positivity and line-item concordance for UC and PCR were consistent with prior reports. The PCR results modified or confirmed treatment in 59/96 (61.5%) and 25/96 (26.0%) of the cases, respectively, with 12/29 (41.4%) and 47/67 (70.1%) having negative and positive PCR results, respectively, resulting in treatment change (difference 28.7%, p < 0.01). Of these, 55/59 (57.3%) were alterations in the antibiotic regimen. PCR use to modify treatment was similar across providers and not statistically different when stratified by patient age, gender, or prior empiric therapy. In 31/59 (52.5%) of the cases, the PCR results modified the treatment where UC would not; conversely, UC would have modified the treatment in 3/37 (8.1%) of the cases where PCR did not (difference 44.4%, p < 0.01). We find that PCR test results are used by clinicians in managing cUTI, and use of this test provides an opportunity to improve antibiotic stewardship in this difficult-to-treat subset of patients.

Epidemiology and risk factors for staphylococcal urinary tract infections in the Moroccan Casablanca area

PURPOSE

This study aimed to ascertain the prevalence and risk factors for developing staphylococcal urinary tract infections (UTIs) in the Casablanca area of Morocco.

METHODS

In Casablanca, Morocco, a retrospective evaluation of 772 UTIs patients was conducted between January 2020 and December 2022. The research included two groups of patients: those with staphylococcal UTIs and those without. Sex, age, chronic illnesses, antibiotic exposure, urinary catheterization, urological surgery, and UTIs history were the risk variables assessed. We employed a logistic regression model to identify the characteristics that were predictive of staphylococcal UTIs.

RESULTS

Eight staphylococcal species were responsible for 16.84% of UTIs in 772 non-repeating individuals. Patients infected with S. saprophyticus (35.38%) were the most common, followed by those infected with S. epidermidis (24.61%), S. aureus (13.85%), and S. hemolyticus (10.78%). Multivariate logistic regression analysis revealed that male sex (95% CI: 0.261-0.563), immunosuppression and immunosuppressive treatments (95% CI: 0.0068-0.64), chronic diseases (95% CI: 0.407-0.965), previous UTIs (95% CI: 0.031-0.228), frequency of urination more than 8 times a day (95% CI:1.04-3.29), frequency of urination once or twice a day (95% CI: 1.05-2.39), and urinary catheterization (95% CI: 0.02-0.22) were the most likely predictors of staphylococcal UTIs. In addition, a larger proportion of patients with staphylococcal UTIs were made aware of the risk factors associated with staphylococcal UTIs (52.31%, χ2 = 4.82, = 0.014).

CONCLUSIONS

This is the first global study to evaluate the predictive factors for acquiring UTIs caused by staphylococci. Monitoring these factors will enable medical authorities to devise effective strategies for managing UTIs and combating antibiotic resistance.

Influence of preoperative urine culture and bacterial species on urogenital sepsis after ureteral flexible lithotripsy in patients with upper urinary tract stones

Objective

This retrospective study aims to identify risk factors for urogenic sepsis in patients with upper urinary tract stones following ureteral flexible lithotripsy (FURL). Additionally, we analyze the clinical characteristics of bacterial infections post-surgery.

Methods

A total of 759 patients who underwent FURL at the Urology Department of Zunyi Medical University were included. Univariate and multivariate Logistic regression analyses were conducted to identify independent risk factors for urogenic sepsis post-FURL. The distribution of bacteria based on preoperative urine cultures was also analyzed. Statistical analysis was performed using R4.2.2 software.

Results

Of the 759 patients, positive preoperative urine culture, urine nitrite positivity, urine white blood cell count (WBC) ≥ 200 cells/μL, residual stones, and neutrophil-to-lymphocyte ratio (NLR) were found to be independent risk factors for urogenic sepsis after FURL. Among the 164 patients with positive preoperative urine cultures, 32 developed urogenic sepsis post-surgery, with 68.75% having positive preoperative cultures. The leading pathogens causing postoperative urogenic sepsis were Escherichia coli (E. coli), Enterococcus faecium, Proteus mirabilis, and Klebsiella pneumoniae. The probabilities of progression to urogenic sepsis were as follows: E. coli 19% (n = 12), Enterococcus faecium 43% (n = 3), Proteus mirabilis 33.3% (n = 1), and Klebsiella pneumoniae 33.3% (n = 1). The ages of affected patients were 47.17 ± 13.2, 53.7, 41, and 79 years, respectively. Rates of comorbid diabetes were 36.4, 66.7, 50, 100%, with nitrite positivity rates at 72.7, 33.3, 50, 0%. Ten female patients were infected with E. coli, while patients infected with Klebsiella pneumoniae had an NLR of 7.62.

Conclusion

Positive preoperative urine culture, urine nitrite positivity, urine WBC ≥ 200 cells/μL, residual stones, and NLR are independent risk factors for urogenic sepsis after FURL. Escherichia coli is the predominant pathogen post-FURL, with notable female prevalence and nitrite-positive urine in infections. Enterococcus faecium infections are associated with diabetes.

Predominance of multidrug-resistant bacteria causing urinary tract infections among symptomatic patients in East Africa: a call for action

Background

In low- and middle-income countries, antibiotics are often prescribed for patients with symptoms of urinary tract infections (UTIs) without microbiological confirmation. Inappropriate antibiotic use can contribute to antimicrobial resistance (AMR) and the selection of MDR bacteria. Data on antibiotic susceptibility of cultured bacteria are important in drafting empirical treatment guidelines and monitoring resistance trends, which can prevent the spread of AMR. In East Africa, antibiotic susceptibility data are sparse. To fill the gap, this study reports common microorganisms and their susceptibility patterns isolated from patients with UTI-like symptoms in Kenya, Tanzania and Uganda. Within each country, patients were recruited from three sites that were sociodemographically distinct and representative of different populations.

Methods

UTI was defined by the presence of >104 cfu/mL of one or two uropathogens in mid-stream urine samples. Identification of microorganisms was done using biochemical methods. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disc diffusion assay. MDR bacteria were defined as isolates resistant to at least one agent in three or more classes of antimicrobial agents.

Results

Microbiologically confirmed UTI was observed in 2653 (35.0%) of the 7583 patients studied. The predominant bacteria were Escherichia coli (37.0%), Staphylococcus spp. (26.3%), Klebsiella spp. (5.8%) and Enterococcus spp. (5.5%). E. coli contributed 982 of the isolates, with an MDR proportion of 52.2%. Staphylococcus spp. contributed 697 of the isolates, with an MDR rate of 60.3%. The overall proportion of MDR bacteria (n = 1153) was 50.9%.

Conclusions

MDR bacteria are common causes of UTI in patients attending healthcare centres in East African countries, which emphasizes the need for investment in laboratory culture capacity and diagnostic algorithms to improve accuracy of diagnosis that will lead to appropriate antibiotic use to prevent and control AMR.

The NLRP3 Inflammasome Is Dispensable in Methicillin-Resistant Staphylococcus aureus Urinary Tract Infection

The NLRP3 inflammasome is a cytoplasmic complex that senses molecular patterns from pathogens or damaged cells to trigger an innate immune defense response marked by the production of proinflammatory cytokines IL-1β and IL-18 and an inflammatory death called pyroptosis. The NLRP3 inflammasome is activated in the urinary tract by a variety of infectious and non-infectious insults. In this study, we investigated the role of the NLRP3 inflammasome by comparing the pathophysiology of methicillin-resistant Staphylococcus aureus (MRSA) ascending UTI in wild-type (WT) and Nlrp3-/- mice. The difference in the bacterial burden detected in the urinary tracts of MRSA-infected WT and Nlrp3-/- was not statistically significant at 6, 24, and 72 h post-infection (hpi). The levels of pro-inflammatory cytokines and chemokines as well as the numbers of granulocytes recruited to bladder and kidney tissues at 24 hpi were also similar between Nlrp3-/- and WT mice. The histopathological analysis of MRSA-infected bladder and kidney sections from Nlrp3-/- and WT mice showed similar inflammation. Overall, these results suggest that MRSA-induced urinary NLRP3 activity does not play a role in the pathophysiology of the ascending UTI.

Investigating Combination Therapy as a Means to Enhance Activity and Repurpose Antimicrobials

Current clinical practice assumes that a single antibiotic given as a bolus or as a course will successfully treat most infections. In modern medicine, this is becoming less and less true with drug-resistant, multi-drug-resistant, extensively drug-resistant, and untreatable infections becoming more common. Where single-drug therapy (monotherapy) fails, we will turn to multi-drug therapy. Alternatively, combination therapy could be useful to prevent the emergence of resistance. Multi-drug therapy is already standard for some multi-drug resistant infections and is the standard for the treatment of some pathogens such as Mycobacterium tuberculosis.The use of combination therapy for everyday infections could be a clear course out of the current AMR crisis we are facing. With every additional drug added to a combination (n + 1) the likelihood of the pathogen evolving resistance drops exponentially.Many generic antibiotics are cheap to manufacture as they have fallen out of patent protection but are less effective at pharmacologically effective doses due to overuse in the past. Combination therapy can combine these generic compounds into cocktails that can not only treat susceptible and resistant infections but can also reduce the risk of new resistances arising and can resuscitate the use of antimicrobials once thought defunct.In this chapter, we will summarize theory behind combination therapy and standard in vitro methodologies used.

Using Hollow Fiber to Model Treatment of Antimicrobial-Resistant Organisms

The use of animal models is still widespread in science but there is a movement away from this manner of experimentation. One option approved by the FDA for human-like studies is the hollow fiber bioreactor (HFS). HFSs are highly controllable, self-contained systems that allow for the modeling of individual tissues and disease phenotypes. Oxygen, drug concentration & half-life, and immune cell invasion are all scalable to human and veterinary conditions using a HFS. There are drawbacks to the systems including cost and contamination so the use of these systems must be carefully managed.With these limitations in mind, the scope of the technology is great. Antimicrobial susceptibility testing (AST) is possible with greater accuracy and clinical validity than classical in vitro techniques making minimal inhibitory concentration (MIC) data generated on the bench more translatable to the clinic.In this chapter, we will outline the background of the HFS and some typical uses.

Investigating Photoactive Antimicrobials as Alternatives (or Adjuncts) to Traditional Therapy

Photodynamic therapy (PDT) is an established therapy used for the treatment of cutaneous skin cancers and other non-infective ailments. There has been recent interest in the opportunity to use aPDT (antimicrobial PDT) to treat skin and soft tissue infections. PDT utilizes photosensitizers that infiltrate all cells and "sensitize" them to a given wavelength of light. The photosensitizer is simply highly absorbent to a given wavelength of light and when excited will produce, in the presence of oxygen, damaging oxygen radicals and singlet oxygen. Bacterial cells are comparatively poor at combatting oxidative stress when compared with human cells therefore a degree of selective toxicity can be achieved with aPDT.In this chapter, we outline methodologies for testing aPDT in vitro using standard lab equipment.

Analysis of Cumulative Antibiogram Reports in Search for Optimal Empirical Urinary Tract Infection Treatment at the Central Teaching Hospital of the Medical University of Lodz, Poland: Results of a 3-Year Surveillance

Urinary tract infections are among the most common bacterial infections, accounting for about two-fifths of all healthcare-associated infections. Appropriate antimicrobial therapy is crucial, e.g., to avoid prolonged hospitalization and limit antimicrobial resistance spread. This study was performed to analyze the microbiological profiles of urinary tract infections in the Central Teaching Hospital in Lodz, Poland, and develop local empirical therapy guidelines. This study was a 3-year retrospective surveillance of the cumulative antibiograms from urine cultures. The procedures were based on the current EUCAST and CLSI guidelines. In 2020-2022, a total of 4656 urine cultures were performed, of which 1134 were positive. The most common bacterial isolates were Escherichia coli, followed by Klebsiella spp. and Enterococcus spp. High levels of susceptibility (>90%) have been observed for carbapenems, piperacillin/tazobactam, amikacin, and nitrofurantoin. Development of the appropriate empirical antimicrobial is a challenging task with persistently high levels of resistance to commonly used antimicrobials. Eventually, we separated the uncomplicated and complicated urinary tract infections in local guidelines and recommended nitrofurantoin and amikacin, respectively, in empiric therapy. The clinicians should make a decision based on the presented symptoms and then-with the urine culture result-correct or continue the therapy.

Patterns of Drug Resistance and Bacterial Pathogen Distribution in Patients with Urinary Tract Infections in the Jiaxing Region from 2020 to 2022

Background

Urinary tract infections (UTIs) and the antibiotic resistance of pathogenic bacteria pose severe threats to public health in the current healthcare environment.

Objective

The purpose of this study was to assess the frequency distribution of bacterial pathogens causing UTIs as well as the characteristics of antibiotic susceptibility and resistance.

Methods

The retrospective study was conducted on 32,391 samples of midstream urine culture from January 1, 2020, to December 31, 2022, in Jiaxing. Bacteria were cultivated on blood agar and identified using MALDI-TOF, and their susceptibility to different antibiotics was assessed using the Kirby-Bauer disk diffusion method and drug sensitivity reaction cards. The SPSS 22 software was used for data analysis. Bivariate logistic regression was used to analyze the risk factors for multidrug resistance.

Results

The total number of positive growth samples was 5378 (16.6%), including 3206 females (59.6%) and 2172 males (40.4%). The four most common urinary pathogens were Escherichia coli (39.2%), Enterococcus faecalis (12.4%), Klebsiella pneumoniae (7.6%), and Enterococcus faecium (7.6%). As far as antibiotic resistance was concerned, Escherichia coli had a greater than 50% resistance rate to ampicillin (76.1%), ciprofloxacin (58.6%), and levofloxacin (51.2%). The multidrug resistance rate was high (41.8%). Low levels of resistance were seen to ertapenem (0.1%), imipenem (0.7%), meropenem (0.7%), piperacillin/tazobactam (0.7%), and nitrofurantoin (1.8%). Klebsiella pneumoniae was highly sensitive to ertapenem (100%). The resistance rates to nitrofurantoin, ceftriaxone, and ciprofloxacin were 37.4%, 37.1%, and 35.1%, respectively. Up to 41% of Escherichia coli strains and 26% of Klebsiella pneumoniae strains produced extended-spectrum lactamases (ESBL). Two species of enterococci were highly sensitive to tigecycline and linezolid (100%), and a small number of norvancomycin-resistant strains (0.2%/two strains) were found.

Conclusion

Escherichia coli and Enterococcus faecium were the most common urinary pathogens in this study. The isolated pathogens showed different sensitivity patterns. Antibiotics should be selected reasonably according to the sensitivity mode of pathogenic bacteria to effectively treat and prevent urinary tract infections.

Defining the Roles of Pyruvate Oxidation, TCA Cycle, and Mannitol Metabolism in Methicillin-Resistant Staphylococcus aureus Catheter-Associated Urinary Tract Infection

Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of complicated urinary tract infection (UTI) associated with the use of indwelling urinary catheters. Previous reports have revealed host and pathogen effectors critical for MRSA uropathogenesis. Here, we sought to determine the significance of specific metabolic pathways during MRSA UTI. First, we identified four mutants from the Nebraska transposon mutant library in the MRSA JE2 background that grew normally in rich medium but displayed significantly reduced growth in pooled human urine (HU). This prompted us to transduce the uropathogenic MRSA 1369 strain with the transposon mutants in sucD and fumC (tricarboxylic acid [TCA] cycle), mtlD (mannitol metabolism), and lpdA (pyruvate oxidation). Notably, sucD, fumC, and mtlD were also significantly upregulated in the MRSA 1369 strain upon exposure to HU. Compared to the WT, the MRSA 1369 lpdA mutant was significantly defective for (i) growth in HU, and (ii) colonization of the urinary tract and dissemination to the kidneys and the spleen in the mouse model of catheter-associated UTI (CAUTI), which may be attributed to its increased membrane hydrophobicity and higher susceptibility to killing by human blood. In contrast to their counterparts in the JE2 background, the sucD, fumC, and mtlD mutants in the MRSA 1369 background grew normally in HU; however, they displayed significant fitness defects in the CAUTI mouse model. Overall, identification of novel metabolic pathways important for the urinary fitness and survival of MRSA can be used for the development of novel therapeutics. IMPORTANCE While Staphylococcus aureus has historically not been considered a uropathogen, S. aureus urinary tract infection (UTI) is clinically significant in certain patient populations, including those with chronic indwelling urinary catheters. Moreover, most S. aureus strains causing catheter-associated UTI (CAUTI) are methicillin-resistant S. aureus (MRSA). MRSA is difficult to treat due to limited treatment options and the potential to deteriorate into life-threatening bacteremia, urosepsis, and shock. In this study, we found that pathways involved in pyruvate oxidation, TCA cycle, and mannitol metabolism are important for MRSA fitness and survival in the urinary tract. Improved understanding of the metabolic needs of MRSA in the urinary tract may help us develop novel inhibitors of MRSA metabolism that can be used to treat MRSA-CAUTI more effectively.

Nanosilver: An Old Antibacterial Agent with Great Promise in the Fight against Antibiotic Resistance

Antibiotic resistance in bacteria is a major problem worldwide that costs 55 billion USD annually for extended hospitalization, resource utilization, and additional treatment expenditures in the United States. This review examines the roles and forms of silver (e.g., bulk Ag, silver salts (AgNO3), and colloidal Ag) from antiquity to the present, and its eventual incorporation as silver nanoparticles (AgNPs) in numerous antibacterial consumer products and biomedical applications. The AgNP fabrication methods, physicochemical properties, and antibacterial mechanisms in Gram-positive and Gram-negative bacterial models are covered. The emphasis is on the problematic ESKAPE pathogens and the antibiotic-resistant pathogens of the greatest human health concern according to the World Health Organization. This review delineates the differences between each bacterial model, the role of the physicochemical properties of AgNPs in the interaction with pathogens, and the subsequent damage of AgNPs and Ag+ released by AgNPs on structural cellular components. In closing, the processes of antibiotic resistance attainment and how novel AgNP-antibiotic conjugates may synergistically reduce the growth of antibiotic-resistant pathogens are presented in light of promising examples, where antibiotic efficacy alone is decreased.

Uropathogens' Antibiotic Resistance Evolution in a Female Population: A Sequential Multi-Year Comparative Analysis

Urinary Tract Infections (UTIs) represent a common finding among females and an important basis for antibiotic treatment. Considering the significant increase in antibiotic resistance during the last decades, this study retrospectively follows the incidence of uropathogens and the evolution of resistance rates in the short and medium term. The current study was conducted at the "Prof. Dr. Th. Burghele" Clinical Hospital, including 1124 positive urine cultures, in three periods of four months between 2018 and 2022. Escherichia coli was the most frequent uropathogen (54.53%), followed by Klebsiella spp. (16.54%), and Enterococcus spp. (14.59%). The incidence of UTIs among the female population is directly proportional to age, with few exceptions. The highest overall resistance in Gram-negative uropathogens was observed for levofloxacin 30.69%, followed by ceftazidime 13.77% and amikacin 9.86%. The highest resistance in Gram-positive uropathogens was observed for levofloxacin 2018-R = 34.34%, 2020-R = 50.0%, and 2022-R = 44.92%, and penicillin 2018-R = 36.36%, 2020-R = 41.17%, and 2022-R = 37.68%. In Gram-negative uropathogens, a linear evolution was observed for ceftazidime 2018-R = 11.08%, 2020-R = 13.58%, and 2022-R = 17.33%, and levofloxacin 2018-R = 28.45%, 2020-R = 33.33%, and 2022-R = 35.0%. The current knowledge dictates the need to continuously assess antimicrobial resistance patterns, information that is necessary for treatment recommendations. The present study aims to determine the current situation and the evolution trends according to the current locoregional situation.

Antibiotic Resistance Profiling of Pathogenic Staphylococcus Species from Urinary Tract Infection Patients in Benin

Staphylococci can cause urinary tract infections (UTIs). These UTIs are among the significant causes of antibiotic resistance and the spread of antibiotic-resistant diseases. The current study is aimed at establishing a resistance profile and determining the pathogenicity of Staphylococcus strains isolated from UTI samples collected in Benin. For this purpose, urine samples (one hundred and seventy) that were collected from clinics and hospitals showed UTI in patients admitted/visited in Benin. The biochemical assay method was used to identify Staphylococcus spp., and the disk diffusion method tested the antimicrobial susceptibility. The biofilm formation ability of the isolates of Staphylococcus spp. was investigated by the colorimetric method. The presence of mecA, edinB, edinC, cna, bbp, and ebp genes was examined by multiplex polymerase chain reaction (PCR). The results showed that Staphylococcus species were identified in 15.29% of all infected individuals and that 58% of these strains formed biofilms. Most Staphylococcus strains (80.76%) were isolated in female samples, and the age group below 30 years appeared to be the most affected, with a rate of 50%. All Staphylococcus strains isolated were 100% resistant to penicillin and oxacillin. The lowest resistance rates were seen with ciprofloxacin (30.8%), gentamicin, and amikacin (26.90%). Amikacin was the best antibiotic against Staphylococcus strains isolated from UTIs. The isolates carried mecA (42.31%), bbp (19.23%), and ebp (26.92%) genes in varying proportions. This study provides new information on the risks posed to the population by the overuse of antibiotics. In addition, it will play an essential role in restoring people's public health and controlling the spread of antibiotic resistance in urinary tract infections in Benin.

Antibiotic Resistance Profile, Biofilm Formation Ability, and Virulence Factors Analysis of Three Staphylococcus spp. Isolates From Urine

Background Staphylococcus spp. is one of the most causative agents of urinary tract infections (UTIs). This study aimed to investigate the antibiotic resistance profile and the virulence factors, including the biofilm formation ability of Staphylococcus spp. isolates from urine. Methodology The agar disk diffusion method was used to test the susceptibility of Staphylococcus isolates to ten antibiotics. The biofilm formation ability was determined using the safranin microplate-based method, and the phospholipase, esterase, and hemolysin activities were assessed by the agar plate method. Results During the study period, a prevalence of 18.12% of urinary tract infections caused by the identified Staphylococci was obtained. All the isolated Staphylococcus aureus and S. epidermidis were resistant to cefazolin. Multi-drug resistance (MDR) was recorded in 80.01%, 81.49%, and 76.20% of S. aureus, S. epidermidis, and S. saprophyticus isolates, respectively. Most of the isolates were moderate biofilm formers, while 44.44%, 31.75%, and 30.16% were positive for phospholipase, esterase, and hemolysin activities, respectively. No relevant correlations were observed between the ability of biofilm formation and the resistance to antibiotics or the expression of virulence factors investigated. Conclusion This study shows that Staphylococcus spp. isolates from patients with clinical manifestations of UTIs expressed a high degree of virulence factors, including the ability of biofilm formation, and exhibited multi-drug resistance to the majority of antimicrobials commonly used for the treatment of Staphylococcal infections.

The Relationship between Preoperative Urine Culture and Post-Percutaneous Nephrostolithotomy Systemic Inflammatory Response Syndrome: A Single-Center Retrospective Study

BACKGROUND

To predict the occurrence of systemic inflammatory response syndrome (SIRS) after percutaneous nephrostrolithotomy(PCNL), preoperative urine culture is a popular method, but the debate about its predictive value is ongoing. In order to better evaluate the value of urine culture before percutaneous nephrolithotomy, we conducted a single-center retrospective study.

METHODS

A total of 273 patients who received PCNL in Shanghai Tenth People's Hospital from January 2018 to December 2020 were retrospectively evaluated. Urine culture results, bacterial profiles, and other clinical information were collected. The primary outcome observed was the occurrence of SIRS after PCNL. Univariate and multivariate logistic regression analysis was performed to determine the predictive factors of SIRS after PCNL. A nomogram was constructed using the predictive factors, and the receiver operating characteristic (ROC) curves and calibration plot were drawn.

RESULTS

Our results showed that there was a significant correlation between positive preoperative urine cultures and the occurrence of postoperative systemic inflammatory response syndrome. Meanwhile, diabetes, staghorn calculi, and operation time were also risk factors for postoperative systemic inflammatory response syndrome. Our results suggest that among the positive bacteria in urine culture before percutaneous nephrolithotomy, Enterococcus faecalis has become the dominant strain.

CONCLUSION

Urine culture is still an important method of preoperative evaluation. A comprehensive evaluation of multiple risk factors should be undertaken and heeded to before percutaneous nephrostrolithotomy. In addition, the impact of changes in bacterial drug resistance is also worthy of attention.

Clinical Microbial Identification of Severe Oral Infections by MALDI-TOF Mass Spectrometry in Stockholm County: an 11-Year (2010 to 2020) Epidemiological Investigation

Growing evidence suggests that oral infections can modify the course of systemic diseases. To date, epidemiological data on microbial oral infections are scarce. Here, we performed a comprehensive analysis of the trend and microbial diversity in oral infection specimens referred for clinical microbiology analysis from 2010 to 2020. The microbes were isolated by culture and were identified via matrix-assisted laser desorption ionization-time of flight mass spectrometry technology (MALDI-TOF MS) throughout the study period. A total of 1,014 referred samples from dental clinics in Stockholm County with dentoalveolar abscesses and jaw osteomyelitis being the main reason were identified. Overall, the microbial composition was dominated by Firmicutes (51%), followed by Bacteroidetes (19%), Proteobacteria (12%), and Actinobacteria (5%). At the genus level, Streptococcus spp. (36%), Prevotella spp. (18%), and Staphylococcus spp. (11%) were among the most frequently reported. Interestingly, a strong increase in trend was noted for Streptococcus anginosus, Streptococcus mitis, Streptococcus sanguinis, Eikenella corrodens, Actinomyces spp., Aggregatibacter aphrophilus, Staphylococcus epidermidis, and Granulicatella adiacens during the study time (R = 0.66 to 0.89, P < 0.05), and a minor increase was noted for Enterococcus faecalis and Klebsiella spp., whereas steady levels were noted for most of the others. The present study shows the diversity of bacteria that have been involved in dental infections during the last decade in the capital of Sweden, as well as the emerging oral microbiota trend, with clear clinical implications on the oral-systemic link. IMPORTANCE Oral diseases and associated microbes are a risk factor for systemic diseases and can change the courses of these diseases. To date, epidemiological data on microbial oral infections are scarce, and longitudinal reports are lacking. We present for the first time the microbial composition of severe oral bacterial infections determined via the MALDI-TOF mass spectrometry technique in a comprehensive study between 2010 and 2020 (11 years) in Stockholm County. The trend and microbial diversity of oral infections were analyzed on referred clinical microbiological samples and were processed by standardized protocols. Trend increase was noted for Streptococcus anginosus, Streptococcus mitis, Streptococcus sanguinis, Eikenella corrodens, Actinomyces spp., Aggregatibacter aphrophilus, Staphylococcus epidermidis, Granulicatella adiacens, Enterococcus faecalis, and Klebsiella spp. Our results provide new insights into the diversity and trend of oral microbiota that were involved in serious oral infections over the past decade in the capital of Sweden and may influence the oral-systemic link.

Analysis of the Distribution and Drug Resistance of Pathogens in Patients with Urinary Tract Infection in the Eastern Chongming Area of Shanghai from 2018 to 2020

Purpose

The aim of this study was to clarify the distribution and drug resistance of pathogens causing urinary tract infection (UTI) and to provide a scientific reference for the rational application of antibiotics.

Patients and Methods

The results of bacterial identification and drug sensitivity analysis of midstream urine samples in our hospital from January 2018 to December 2020 were retrospectively analyzed. The data were analyzed using WHONET 5.6 and SPSS 26.0 (IBM) software.

Results

In all, 1786 pathogens were isolated from 13,141 midstream urine culture samples. Of these, 1093 (61.2%) were gram-negative bacteria, mainly Escherichia coli [29.1%] and Klebsiella pneumoniae [14.3%]; 543 (30.4%) were gram-positive bacteria, mainly Enterococcus faecium [16.7%] and Enterococcus faecalis [8.4%]; and 150 (8.4%) were fungal isolates, with the most common being Candida albicans (3.7%). The resistance rates of E. coli to piperacillin/tazobactam (3.4% vs 10.0%, p<0.05), ampicillin/sulbactam (43.0% vs 53.8%, p<0.05), and ciprofloxacin (58.0% vs 72.9%, p<0.05) increased significantly. K. pneumoniae was highly sensitive to ertapenem (100%). Two Enterococcus spp were highly sensitive to tigecycline (100%), and a small number of norvancomycin-resistant strains were found. The drug resistance rate of E. faecium to quinupristin was 6.7%. The drug resistance rates of E. faecalis to furantoin and ampicillin were 4.0% and 4.7%, respectively.

Conclusion

The pathogens that cause UTIs in patients are diverse, with the most common being E. coli. The isolated pathogens exhibited different resistance patterns. Antibiotics should be rationally selected based on the resistance patterns of the pathogens.

Analysis of virulence genes, drug resistance detection, and pathogenicity in Enterococcus from farm animals

This study aimed to investigate the presence of eight virulence genes (ace, asa1, esp, efaA, gelE, cylA, agg, fsr) in Enterococcus from a variety of animals and to explore the drug resistance and pathogenicity. This could provide a theoretical basis for clinical treatment of Enterococcus infections. Anal swabs from pigs, chickens, cattle, and dogs in farms and pet hospitals were collected for Enterococcus isolation and identification. Eight virulence genes were detected (PCR method), and drug resistance was assessed (drug-sensitive paper method). The strains containing different virulence genes were then divided into EV1, EV2, and EV3 groups. The LD₅₀ and pathogenicity was examined by intra-peritoneal injection to infect mice. Differences were found in the detection rates of virulence genes in Enterococcus from the different animals. The highest overall detection rate was for the esp gene (78.0%), and the lowest for the cylA gene (15.5%). Eight genes were detected most frequently in Enterococcus from dogs and least frequently from cattle. Among the Enterococcus strains from four variety of animals, drug resistance was highest against sulfamethoxazole (100%), cefotaxime (>97%), and cefotaxitin (>93%). Drug resistance was lowest against vancomycin (0%), levofloxacin (<12%) and ciprofloxacin (<13%). The LD₅₀ for each of the three groups was EV1_LD50=8.71×10⁹CFU， EV2_LD50=2.34×10¹⁰CFU，and EV3_LD50=9.33×10¹⁰CFU. The Enterococcus12LD₅₀ dose group caused significant clinical symptoms in mice, with pathological effects on the heart, liver, lungs, and kidneys, and particularly on the urinary system. The abundance of Enterococcus virulence genes, drug resistance, and pathogenicity vary among different animal origins, and the pathology caused by Enterococcus requires effective treatment protocols based on species and regional characteristics.

Point-of-care tests for pediatric urinary tract infections in general practice: a diagnostic accuracy study

BACKGROUND

Early diagnosis of pediatrics urinary tract infections in the outpatient settings is challenging but essential to prevent hospitalization and kidney damage.

OBJECTIVE

We aimed to evaluate the diagnostic test accuracy of a selection of point-of-care tests for pediatric urinary tract infections in general practice.

METHODS

A prospective cross-sectional study in 26 general practices in Flanders, Belgium (clinicaltrials.gov, NCT03835104). Urine was sampled systematically from children between 3 months to 18 years presenting with an acute illness of maximum 10 days. Samples were analyzed at the central laboratory with a routine dipstick test, the Utriplex test, the Uriscreen test and the Rapidbac as index tests, and with urine culture showing more than 105 colony-forming units per milliliter of one pathogen as reference standard. For each test, we calculated sensitivity, specificity, positive and negative likelihood ratios, and predictive values with 95% confidence intervals.

RESULTS

Three-hundred urine samples were available for analysis of which 30 samples were culture positive (10%). Sensitivities and specificities were 32% (95% CI 16%-52%) and 86% (95% CI 82%-90%) for the dipstick test, 21% (95% CI 8%-40%) and 94% (95% CI 91%-97%) for the Utriplex test, 40% (95% CI 16%-68%) and 83% (95% CI 75%-88%) for the Rapidbac test, and 67% (95% CI 38%-88%) with 69% (95% CI 60%-76%) for the Uriscreen test.

CONCLUSION

All 4 point-of-care tests were suboptimal for use in the broad range of children presenting with acute illnesses to general practice. General practitioners need novel methods for obtaining reliable urine samples during the time of the consultation, especially for children not yet toilet-trained.

No Correlation between Biofilm-Forming Capacity and Antibiotic Resistance in Environmental Staphylococcus spp.: In Vitro Results

The production of biofilms is a critical factor in facilitating the survival of Staphylococcus spp. in vivo and in protecting against various environmental noxa. The possible relationship between the antibiotic-resistant phenotype and biofilm-forming capacity has raised considerable interest. The purpose of the study was to assess the interdependence between biofilm-forming capacity and the antibiotic-resistant phenotype in 299 Staphylococcus spp. (S. aureus n = 143, non-aureus staphylococci [NAS] n = 156) of environmental origin. Antimicrobial susceptibility testing and detection of methicillin resistance (MR) was performed. The capacity of isolates to produce biofilms was assessed using Congo red agar (CRA) plates and a crystal violet microtiter-plate-based (CV-MTP) method. MR was identified in 46.9% of S. aureus and 53.8% of NAS isolates (p > 0.05), with resistance to most commonly used drugs being significantly higher in MR isolates compared to methicillin-susceptible isolates. Resistance rates were highest for clindamycin (57.9%), erythromycin (52.2%) and trimethoprim-sulfamethoxazole (51.1%), while susceptibility was retained for most last-resort drugs. Based on the CRA plates, biofilm was produced by 30.8% of S. aureus and 44.9% of NAS (p = 0.014), while based on the CV-MTP method, 51.7% of S. aureus and 62.8% of NAS were identified as strong biofilm producers, respectively (mean OD570 values: S. aureus: 0.779±0.471 vs. NAS: 1.053±0.551; p < 0.001). No significant differences in biofilm formation were observed based on MR (susceptible: 0.824 ± 0.325 vs. resistant: 0.896 ± 0.367; p = 0.101). However, pronounced differences in biofilm formation were identified based on rifampicin susceptibility (S: 0.784 ± 0.281 vs. R: 1.239 ± 0.286; p = 0.011). The mechanistic understanding of the mechanisms Staphylococcus spp. use to withstand harsh environmental and in vivo conditions is crucial to appropriately address the therapy and eradication of these pathogens.

How Advanced Is Our Understanding of the Role of Intestinal Barrier Dysfunction in the Pathogenesis of Recurrent Urinary Tract Infections

A comprehensive understanding of urinary tract infections (UTIs), one of the most common human infections, is required as they are complex and poorly understood diseases. Periurethral and vaginal colonization by rectal flora, with the constant presence of pathogens in the urethra, is the initial step of the recurrent UTIs pathway. Current scientific data describe the genetic, etiological, biological, and behavioral risk factors for recurring UTIs, but they do not include the effect of intestinal barrier function on the disease. Although gut microbiota has been proposed as the main source for UTIs, the cross-talk between intestinal barrier dysfunction and the recurrence of UTIs has not yet been supported by scientific data. In this opinion review, based on published data and the results of our clinical studies, I aimed to outline the possible contribution of intestinal barrier dysfunction to the pathogenesis of recurrent UTIs. I believe that the unanswered questions raised by this review can guide further experimental and controlled studies to clarify the mechanisms underlying the role of intestinal barrier dysfunction in the pathogenesis of recurrent UTIs.

Does the COVID Pandemic Modify the Antibiotic Resistance of Uropathogens in Female Patients? A New Storm?

Urinary tract infections (UTIs) represent a common pathology among female patients, leading to overprescribing antibiotics, globally. The emergence of the COVID-19 pandemic has dramatically increased the incidence of this particular viral pneumonia with secondary bacterial superinfection, resulting in continuous therapeutic or prophylactic recommendations of antibiotic treatment; thus, an updated analysis of current antimicrobial resistance among uropathogens is mandatory. This cross-sectional retrospective study conducted in two university hospitals in Bucharest, Romania analyzed 2469 positive urine cultures, among two different periods of 6 months, before and during the COVID-19 pandemic. The most common pathogen was Escherichia coli 1505 (60.95%), followed by Klebsiella spp. 426 (17.25%). Enterococcus spp. was the leading Gram-positive pathogen 285 (11.54%). In gram negative bacteria, in almost all cases, an increased in resistance was observed, but the highest increase was represented by quinolones in Klebsiella spp., from 16.87% to 35.51% and Pseudomonas from 30.3% to 77.41%; a significant increase in resistance was also observed for carbapenems. Surprisingly, a decrease in resistance to Penicillin was observed in Enterococcus spp., but the overall tendency of increased resistance is also maintained for gram positive pathogens. The lack of data on the influence of the COVID-19 pandemic on uropathogens’ resistance promotes these findings as important for every clinician treating UTIs and for every specialist in the medical field in promoting reasonable recommendations of antibiotic therapies.

Potent, Broad-Spectrum Antimicrobial Effects of S-Nitroso-N-acetylpenicillamine-Impregnated Nitric Oxide-Releasing Latex Urinary Catheters

Although numerous prevention and intervention techniques have been developed to counteract catheter-associated urinary tract infections (CAUTIs), urinary catheters remain one of the most common sources of hospital-acquired infections. Nitric oxide (NO), a gaseous free radical responsible for regulating many physiological functions in the body, has gained immense popularity due to its potent, broad-spectrum antimicrobial activity, which is capable of combating medical device-associated infections. In this work, a straightforward solvent-swelling method was used to load the NO donor S-nitroso-N-acetyl-penicillamine (SNAP) into commercial latex catheters (SNAP-UCs) for the first time. The effects of swelling catheters with different concentrations of SNAP solutions (25-125 mg/mL SNAP in tetrahydrofuran (THF)) were studied by measuring the NO release kinetics, SNAP loading, and SNAP leaching. SNAP-UCs impregnated with a 50 mg/mL SNAP-THF solution were found to maximize the amount of SNAP loaded into the latex (0.115 ± 0.009 mg SNAP/mg catheter) and showed physiological levels of NO release (>2 × 10^-10 mol min^-1 cm^-2) over 7 days and minimal SNAP leaching (<2%). SNAP-UCs showed impressive in vitro contact-based and diffusible antimicrobial efficacy against three CAUTI-associated pathogens, reducing the viability of adhered and planktonic Escherichia coli, Proteus mirabilis, and Staphylococcus aureus by ∼98.0 to 99.1% (adhered) and 86.3-96.3% (planktonic) compared to control latex catheters. In vitro cytotoxicity against 3T3 mouse fibroblasts using a CCK-8 assay showed that SNAP-UCs were noncytotoxic (>90% viability). In summary, SNAP-UCs show stable, noncytotoxic NO release characteristics capable of potent, broad-spectrum antimicrobial activity, demonstrating great potential for reducing the devastating effects associated with CAUTIs.

Studies on Virulence and Extended-Spectrum β-Lactamase-Producing Uropathogenic Escherichia coli Isolates and Therapeutic Effect of Fosfomycin in Acute Pyelonephritis Mice

The understanding about virulence factors (VFs) and the drug resistance of uropathogenic Escherichia coli (UPEC) helps us understand the pathogenesis of urinary tract infections (UTIs) and make better decisions for clinical treatment. This study examined the correlation between the extended-spectrum β-lactamases (ESBLs) phenotype and VFs in UPEC strains. In addition, we validated the therapeutic potential of fosfomycin in acute pyelonephritis mice. From May 2017 to November 2018, 22 nonduplicate E coli. strains were isolated from UTI patients. PCR was utilized to detect the distribution of virulence genes. We also analyzed the ESBL phenotype in E coli. We further evaluated the therapeutic effect of intravenous fosfomycin treatment in the acute pyelonephritis (APN) model. All 22 UPEC strains expressed the type 1 fimbriae (FimH) gene and more than 50% (12/22) of strains produced ESBLs. The detection rates of the iron acquisition-associated genes ChuT and IutA were 77.3% (n = 17) and 50% (n = 11) and those of P fimbria papA and papC genes were 45% (n = 10) and 50% (n = 11), respectively. Though the VFs were closely related with pathologenicity, the relationship between VFs and ESBLs still needs further investigation. Furthermore, intravenous fosfomycin 800 mg/kg significantly reduced the bacterial load and the inflammatory infiltration in the bladder and kidney, maintaining the structural integrity of the kidney. Intravenous fosfomycin administration can be used for the treatment of acute pyelonephritis caused by highly pathogenic and drug-resistant UPEC strains.

Urinary Tract Infection Etiological Profiles and Antibiotic Resistance Patterns Varied Among Different Age Categories: A Retrospective Study From a Tertiary General Hospital During a 12-Year Period

Background

Urinary tract infections (UTIs) are among the most common infections worldwide. With continuing trends of antibiotic resistance, the etiological distribution and antibiotic susceptibility surveillance are of great importance for empirical antimicrobial therapy. The risk factors and clinical circumstances of UTI among different age categories varied; thus, the pathogens and antimicrobial susceptibilities of UTI may also change with age. The aim of this study was to compare the etiological profiles and antibiotic resistance patterns of UTIs sorted by different age categories from a tertiary general hospital during a 12-year period.

Methods

All positive urine culture results from non-repetitive UTI patients in our hospital from January 2009 to December 2020 were collected retrospectively. The microbial distribution and antibiotic resistance rates were analyzed by WHONET 5.6 software. The etiological profiles sorted by different age categories (newborn, pediatric, adult, and geriatric) and antibiotic resistance rates of the top five pathogens were analyzed.

Results

A total of 13,308 non-repetitive UTI patients were included in our study. Enterococcus faecium was dominant in newborn (45%, n = 105), and replaced by Escherichia coli in pediatric (34%, n = 362), adult (43%, n = 3,416), and geriatric (40%, n = 1,617), respectively. The etiological profiles of different age categories were divergent, sorted by genders (male and female) and ward types (outpatient, inpatient, ICU, and emergency). E. coli, Klebsiella pneumoniae, Enterococcus faecalis, E. faecium, and Pseudomonas aeruginosa were the top five pathogens in all age categories. The resistance rates of cefoperazone–sulbactam and piperacillin–tazobactam in E. coli were low in all age categories. The resistance rates of other cephalosporins, carbapenems, and fluoroqinolones in K. pneumoniae were higher in geriatric patients overall. E. faecium was more resistant than E. faecalis in all age categories. Multidrug resistance increased with age, which was more serious in geriatric patients.

Conclusion

The UTI etiological profiles and antibiotic resistance patterns varied among different age categories, especially in pediatric and geriatric patients; thus, a different antibiotic therapy for various age categories should be considered when initiating empirical antimicrobial therapies.

In vitro activities of thiazolidione derivatives combined with daptomycin against clinical Enterococcus faecium strains

Background

Previous reports have demonstrated two thiazolidione derivatives (H2-60 and H2-81) can robustly inhibit the planktonic growth and biofilm formation of S. epidermidis and S. aureus by targeting the histidine kinase YycG. Whereas the antibacterial and anti-biofilm activity of these two thiazolidione derivatives (H2-60 and H2-81) against Enterococcus faecium remains elusive. Here, the pET28a-YycG recombinant plasmid were in vitro expressed in E. coli competent cell BL21 (DE3) and induced to express YycG’ protein (conding HisKA and HATPase_c domain) by 0.5 mM IPTG and was purified by Ni – NTA agarose and then for the autophosphorylation test. Antimicrobial testing and time-killing assay were also be determined. Anti-biofilm activity of two derivatives with sub-MIC concentration towards positive biofilm producers of clinical E. faecium were detected using polystyrene microtiter plate and CLSM.

Results

The MICs of H2-60 and H2-81 in the clinical isolates of E. faecium were in the range from 3.125 mg/L to 25 mg/L. Moreover, either H2-60 or H2-81 showed the excellent bactericidal activity against E. faecium with monotherapy or its combination with daptomycin by time-killing assay. E. faecium planktonic cells can be decreased by H2-60 or H2-81 for more than 3 × log10 CFU/mL after 24 h treatment when combined with daptomycin. Furthermore, over 90% of E. faecium biofilm formation could markedly be inhibited by H2-60 and H2-81 at 1/4 × MIC value. In addition, the frequency of the eradicated viable cells embedded in mature biofilm were evaluated by the confocal laser microscopy, suggesting that of H2-60 combined with ampicillin or daptomycin was significantly high when compared with single treatment (78.17 and 74.48% vs. 41.59%, respectively, P < 0.01).

Conclusion

These two thiazolidione derivatives (H2-60 and H2-81) could directly impact the kinase phosphoration activity of YycG of E. faecium. H2-60 combined with daptomycin exhibit the excellent antibacterial and anti-biofilm activity against E. faecium by targeting YycG.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02423-8.

Linezolid for the Treatment of Urinary Tract Infections Caused by Vancomycin-Resistant Enterococci

Vancomycin-resistant enterococci (VRE) account for a large proportion of hospital-acquired infections. Determining optimal treatment of VRE urinary tract infections (UTIs) is challenging. The purpose of this study was to determine if a difference in efficacy or safety exists between linezolid and non-linezolid treatments for VRE UTIs. This retrospective cohort evaluated patients admitted between 1 June 2012–30 November 2017 who were treated for VRE UTI. Patients must have had at least one sign, symptom, or laboratory confirmation of UTI to be included. The primary endpoint of this study was difference in clinical cure between linezolid and non-linezolid treatment options. Secondary endpoints included 30-day recurrence, 30-day infection-related readmission, inpatient mortality, infection-related hospital length of stay (LOS), and time to appropriate therapy. A total of 45 patients (33 linezolid and 12 non-linezolid) were included. Clinical cure occurred in 71.4% linezolid and 58.3% non-linezolid (p = 0.476). No patients had a 30-day infection-related readmission or 30-day recurrence. Of the 45 patients, 6 (13.3%) patients died during admission, and 5 of those deaths were in the linezolid group (p = 1.000). No significant difference was found for clinical cure between linezolid and non-linezolid treatment options for VRE UTIs.

Distribution and drug resistance of pathogens causing urinary tract infection in patients with urinary calculi

OBJECTIVE

This study set out to clarify the distribution and drug resistance of pathogens causing urinary tract infection (UTI) in patients with urinary calculi.

METHODS

Pathogens were isolated from urine samples of patients with urinary calculi also complicated with UTIs, during the period from 2015 to 2019, and the samples were cultured for drug sensitivity testing to study the drug resistance of pathogens. The results were analyzed by SPSS 22.0 software.

RESULTS

Gram-negative bacteria were the main pathogens found in patients with urinary calculi complicated with UTI (84.52%). Escherichia coli, Enterococcus faecalis and Monilia albicans were the most common Gram-negative bacteria (48.84%), Gram-positive bacteria (34.78%) and fungus (29.41%), respectively. The UTI rates were higher in female patients than in male patients, and were higher in patients ≥ 60 years old compared with those < 60 years old. Escherichia coli and Klebsiella pneumoniae had the highest resistance to ampicillin and the lowest resistance to imipenem. Enterococcus faecalis Enterococcus Faecium had the highest resistance to penicillin and ampicillin, but the lowest resistance to vancomycin and linezolid.

CONCLUSION

The present study found that the pathogenic bacteria found in patients with urinary calculi complicated with UTI are mainly Gram-negative bacteria; and Escherichia coli is the main pathogenic bacteria causing the infection. Gender and age may be risk factors for urinary calculi complicated with UTI. Antibiotics should be selected reasonably according to the drug resistance pattern of pathogenic bacteria in clinical anti-infection management.

Study on Demethoxycurcumin as a Promising Approach to Reverse Methicillin-Resistance of Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) has always been a threatening pathogen. Research on phytochemical components that can replace antibiotics with limited efficacy may be an innovative method to solve intractable MRSA infections. The present study was devoted to investigate the antibacterial activity of the natural compound demethoxycurcumin (DMC) against MRSA and explore its possible mechanism for eliminating MRSA. The minimum inhibitory concentrations (MICs) of DMC against MRSA strains was determined by the broth microdilution method, and the results showed that the MIC of DMC was 62.5 μg/mL. The synergistic effects of DMC and antibiotics were investigated by the checkerboard method and the time–kill assay. The ATP synthase inhibitors were employed to block the metabolic ability of bacteria to explore their synergistic effect on the antibacterial ability of DMC. In addition, western blot analysis and qRT-PCR were performed to detect the proteins and genes related to drug resistance and S. aureus exotoxins. As results, DMC hindered the translation of penicillin-binding protein 2a (PBP2a) and staphylococcal enterotoxin and reduced the transcription of related genes. This study provides experimental evidences that DMC has the potential to be a candidate substance for the treatment of MRSA infections.

Correlation Between Biofilm-Formation and the Antibiotic Resistant Phenotype in Staphylococcus aureus Isolates: A Laboratory-Based Study in Hungary and a Review of the Literature

Introduction

Staphylococcus aureus (S. aureus) is an important causative pathogen in human infections. The production of biofilms by bacteria is an important factor, leading to treatment failures. There has been significant interest in assessing the possible relationship between the multidrug-resistant (MDR) status and the biofilm-producer phenotype in bacteria. The aim of our present study was to assess the biofilm-production rates in clinical methicillin-susceptible S. aureus [MSSA] and methicillin-resistant S. aureus [MRSA] isolates from Hungarian hospitals and the correlation between resistance characteristics and their biofilm-forming capacity.

Methods

A total of three hundred (n=300) S. aureus isolates (corresponding to MSSA and MRSA isolates in equal measure) were included in this study. Identification of the isolates was carried out using the VITEK 2 ID/AST system and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method and E-tests, confirmation of MRSA status was carried out using PBP2a agglutination assay. Biofilm-production was assessed using the crystal violet (CV) tube-adherence method and the Congo red agar (CRA) plate method.

Results

There were significant differences among MSSA and MRSA isolates regarding susceptibility-levels to commonly used antibiotics (in case of erythromycin, clindamycin and ciprofloxacin: p<0.001, gentamicin: p=0.023, sulfamethoxazole/trimethoprim: p=0.027, rifampin: p=0.037). In the CV tube adherence-assay, 37% (n=56) of MSSA and 39% (n=58) of MRSA isolates were positive for biofilm-production, while during the use of CRA plates, 41% (n=61) of MSSA and 44% (n=66) of MRSA were positive; no associations were found between methicillin-resistance and biofilm-production. On the other hand, erythromycin, clindamycin and rifampin resistance was associated with biofilm-positivity (p=0.004, p<0.001 and p<0.001, respectively). Biofilm-positive isolates were most common from catheter-associated infections.

Discussion

Our study emphasizes the need for additional experiments to assess the role biofilms have in the pathogenesis of implant-associated and chronic S. aureus infections.

Nanomaterials for the Diagnosis and Treatment of Urinary Tract Infections

The diagnosis and treatment of urinary tract infections (UTIs) remain challenging due to the lack of convenient assessment techniques and to the resistance to conventional antimicrobial therapy, showing the need for novel approaches to address such problems. In this regard, nanotechnology has a strong potential for both the diagnosis and therapy of UTIs via controlled delivery of antimicrobials upon stable, effective and sustained drug release. On one side, nanoscience allowed the production of various nanomaterial-based evaluation tools as precise, effective, and rapid procedures for the identification of UTIs. On the other side, nanotechnology brought tremendous breakthroughs for the treatment of UTIs based on the use of metallic nanoparticles (NPs) for instance, owing to the antimicrobial properties of metals, or of surface-tailored nanocarriers, allowing to overcome multidrug-resistance and prevent biofilm formation via targeted drug delivery to desired sites of action and preventing the development of cytotoxic processes in healthy cells. The goal of the current study is therefore to present the newest developments for the diagnosis and treatment of UTIs based on nanotechnology procedures in relation to the currently available techniques.

A Novel Ivermectin-Derived Compound D4 and Its Antimicrobial/Biofilm Properties against MRSA

Methicillin-resistant Staphylococcus aureus (MRSA) and its biofilms infection is still a serious threat to global health. It is urgent to develop efficient drugs by repositioning or designing drugs to solve this problem. In this study, the antibacterial/biofilm activity and mechanisms of ivermectin (D) and its 4″-position amino substitution derivative (D4) against MRSA were investigated. The minimum inhibitory concentration (MIC) of D was 20 μg/mL, which is four times higher than D4 (MIC = 5 μg/mL). The mechanism research demonstrated that D4 was more potent than D at destroying bacterial cell wall, permeating cell membrane (6.25-36.0% vs 1.92-6.04%) and binding to MRSA genomic DNA. Moreover, after incubation with 10-40 μg/mL D4 for 24 h, the percentages of biofilm decreased by 21.2-92.9%, which was more effective than D (no significant change at 40 μg/mL). The antibiofilm effect is achieved by regulating the expression of related genes (RSH, relQ, rsbU, sigB, spA, and icaD). Additionally, though the higher hemolysis makes D4 a safety risk for intravenous injection, other administration options could be considered as well. Therefore, all the results have indicated that D4 may be a potential candidate compound for the treatment of MRSA and its biofilm infections.

Bacterial Profile, Antibiotic Susceptibility Pattern and Associated Factors Among Patients Attending Adult OPD at Hawassa University Comprehensive Specialized Hospital, Hawassa, Ethiopia

Background

Urinary tract infection (UTI) is a common health problem occurring when infectious agents colonize, invade, and propagate the urinary tract including the urethra, bladder, renal pelvis, or renal parenchyma. The study aimed to determine the prevalence of symptomatic UTI, drug resistance pattern, and its associated factors among patients attending adult outpatient department (OPD) at Hawassa University Comprehensive Specialized Hospital (HUCSH).

Methods

A cross-sectional study was conducted from October 2018 to February 2019 among adults ≥18 years old with symptoms of UTI. Processing of specimens for culture and identification was done. Antimicrobial susceptibility was done for positive urine cultures. Data entry and analysis were performed using SPSS version 23.0 software. Bivariate and multivariate logistic regression analysis test results were used.

Results

The overall prevalence of symptomatic urinary tract infection was 32.8% (95% CI: 28.3–37.6). The predominant isolated bacteria was E. coli 46 (36.2%) followed by S. aureus 21 (16.5%). Gram-negative bacteria were a high level of resistance to ampicillin (71.4%), and tetracycline (68.2%). Gram-positive bacteria were highly resistant to norfloxacin (77.7%). The overall prevalence of multi-drug resistant isolates was 102 (80.3%). Being female, no formal education, and self-medication history had more likely cause UTI.

Conclusion

Urinary tract infection (UTI) among adults was prevalent in the study area. Being female, educational status and self-medication history had a significant association with UTI. Resistance to ampicillin, tetracycline, and norfloxacin was high. Therefore, culture and antibiotic susceptibility testing should be routinely used for the proper management of patients with UTI.

Fusidic Acid Resistance Determinants in Methicillin-Resistant Staphylococcus aureus Isolated in Kuwait Hospitals

OBJECTIVE

The aim of this study was to investigate the genetic determinants of fusidic acid (FA) resistance in MRSA isolated from patients in Kuwait hospitals.

METHODS

The minimum inhibitory concentration (MIC) of FA was tested with E-test strips. Genetic determinants of FA were determined by PCR and DNA microarray. Staphylococcal protein A gene (spa) typing and DNA microarray analysis were used to study their genetic backgrounds.

RESULTS

The FA MIC ranged from 2 mg/L to >256 mg/L. Of the 97 isolates, 79 (81.4%) harbored fusC, 14 isolates harbored fusA mutations (fusA), and 4 isolates harbored fusB. Isolates with fusA mutations expressed high FA MIC (MIC >256 mg/L), whereas those with fusC and fusB expressed low FA MIC (MIC 2-16 mg/L). The isolates belonged to 23 spa types and 12 clonal complexes (CCs). The major spa types were t688 (n = 25), t311 (n = 14), t860 (n = 8), and t127 (n = 6) which constituted 54.6% of the isolates. The 12 CCs were CC1, CC5, CC8, CC15, CC22, CC80, CC88, and CC97 with CC5 (45.6%) and CC97 (13.2%) as the dominant CCs.

CONCLUSIONS

The MRSA isolates belonged to diverse genetic backgrounds with the majority carrying the fusC resistance determinants. The high prevalence of FA resistance belonging to diverse genetic backgrounds warrants a review of FA usage in the country to preserve its therapeutic benefits.

The Importance of Reporting Clinical and Epidemiological Data in Urology: Local Experiences and Insights from the International Literature

Pathologies of the genito-urinary tract are responsible for a considerable disease burden worldwide, leading to significant losses of income, lost working days, increased expenditures for national healthcare systems, and decreased quality of life (QoL) in the affected patients. Among these diseases, infections and malignancies in this anatomical region are some of the most important illnesses in human medicine; nevertheless, benign prostate hyperplasia (BPH), erectile dysfunction, hypospadias, urinary incontinence, and vesicoureteral reflux are also relevant disorders affecting millions. The publication of various microbiological and clinical studies in urology from different geographical regions has important ramifications from the standpoint of epidemiology: on one hand, reported data may influence the development of therapeutic guidelines for urinary tract infections (UTIs) (empiric antibiotic-therapy) and malignancies (including classical cytotoxic drug protocols and next-generation anticancer therapies) both locally and internationally; on the other hand, the relevant stakeholders and government representatives often base their decisions on published evidence. Therefore, novel studies in the field of urology are strongly encouraged to maintain and improve the high standard of patient care internationally and to ensure continuous information supply for international datasets on the causative agents of UTIs and cancer registries. The present Editorial aims to highlight some relevant studies published from the field of urology in Medicina over the last several years.