Uropathogenic Escherichia coli endeavors: an insight into the characteristic features, resistance mechanism, and treatment choice.

Uropathogenic Escherichia coli (UPEC) are the strains diverted from the intestinal status and account mainly for uropathogenicity. This pathotype has gained specifications in structure and virulence to turn into a competent uropathogenic organism. Biofilm formation and antibiotic resistance play an important role in the organism's persistence in the urinary tract. Increased consumption of carbapenem prescribed for multidrug-resistant (MDR) and Extended-spectrum-beta lactamase (ESBL)-producing UPECs, has added to the expansion of resistance. The World Health Organization (WHO) and Centre for Disease Control (CDC) placed the Carbapenem-resistant Enterobacteriaceae (CRE) on their treatment priority lists. Understanding both patterns of pathogenicity, and multiple drug resistance may provide guidance for the rational use of anti-bacterial agents in the clinic. Developing an effective vaccine, adherence-inhibiting compounds, cranberry juice, and probiotics are non-antibiotical approaches proposed for the treatment of drug-resistant UTIs. We aimed to review the distinguishing characteristics, current therapeutic options and promising non-antibiotical approaches against ESBL-producing and CRE UPECs.

Molecular diagnosis, phylogenetic analysis, and antifungal susceptibility profiles of Candida species isolated from neutropenic oncological patients.

BACKGROUND: Neutropenia is the most important cause of life-threatening invasive fungal infections (IFIs). Here, we studied the frequency and antifungal susceptibility profiles of Candida species that colonized or caused infections among neutropenic patients with solid or hematological malignancies. METHODS: A total of 362 clinical samples were collected from 138 patients. After initial isolation using a mix of mycological methods, isolates were screened using chromogenic culture media. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was applied for molecular identification. Positive or suspected cases were confirmed using the reference method of sequencing. Antifungal susceptibility testing for voriconazole and caspofungin was carried out using the microbroth dilution method. An in-silico assay was applied for phylogenetic analysis. RESULTS: Thirty-four Candida strains were isolated. C. albicans (47.06%) and C. glabrata (29.41%) were the most frequent strains. Antifungal treatment reduced the chance of Candida colonization by almost 76% in neutropenic patients (OR: 1.759; 95% CI: 1.349 to 2.390; p value: 0.000). An unusual and non-resistant strain, C. lambica, was reported from the bloodstream of a 56-year-old man with hematologic malignancy (HM). Eight isolates were non-susceptible, and one isolate was resistant to voriconazole. Also, four isolates were non-susceptible to caspofungin. CONCLUSION: We can conclude that there is a cause-and-effect relationship between neutropenia, HM background, and Candida species separated from neutropenic patients, which can lead to possible infections. Further and repetitive studies are recommended using different molecular methods for better prediction and management of fungal infections in neutropenic patients.

Interaction Between Altered Gut Microbiota and Sepsis: A Hypothesis or an Authentic Fact?

Sepsis, as an important public health concern, is one of the leading causes of death in hospitals around the world, accounting for 25% of all deaths. Nowadays, several factors contribute to the development of sepsis. The role of the gut microbiota and the response state of the aberrant immune system is dominant. The effect of the human microbiome on health is undeniable, and gut microbiota is even considered a body organ. It is now clear that the alteration in the normal balance of the microbiota (dysbiosis) is associated with a change in the status of immune system responses. Owing to the strong association between the gut microbiota and its metabolites particularly short-chain fatty acids with many illnesses, the gut microbiota has a unique position in the research of microbiologists and even clinicians. This review aimed to analyze studies' results on the association between microbiota and sepsis, with a substantial understanding of their relationship. As a result, an extensive and comprehensive search was conducted on this issue in existing databases.

Aptitude of Uropathogenic Escherichia coli in Renal Transplant Recipients: A Comprehensive Review on Characteristic Features, and Production of Extended Spectrum ß-Lactamase.

Urinary tract infection is the most common infection in almost half of the renal transplant patients. The development of UTI in these patients may progress to bacteremia, acute T cell-mediated rejection, impaired allograft function, or allograft loss, along with the increased risk of hospitalization and death. Among various pathogens implicated, Uropathogenic E. coli (UPEC), especially sequence type 131 (ST131), is the most virulent and multidrug-resistant pathogen. High antimicrobial resistance to most ß-lactam antibiotics, mediated by extended spectrum ß-lactamases (ESBLs) produced by UPEC, is a challenge in the clinical management of UTIs in kidney transplant recipients. Indeed, multidrug resistance to ß-lactam antibiotics is a direct consequence of ESBL production. Resistance to other antibiotics such as aminoglycosides, fluoroquinolones, and trimethoprim-sulphamethoxazole has also been reported in ESBLs-producing UPEC, which reduces the therapeutic options, rising healthcare-associated costs and subsequently leads to renal failure or even graft loss. In this review, we aimed to discuss the post-transplant risk factors of UTI, UPEC virulence factors (VF), and the related factors including quorum sensing, and stress resistance genes. Furthermore, we searched for the current treatment strategies and some of the alternate approaches proposed as therapeutic options that may affirm the treatment of ESBL-producing UPEC.

Evidence of High-Risk Human Papillomavirus in Esophageal Cancer in East Azerbaijan Province, Northwest of Iran.

BACKGROUND: Human papillomavirus (HPV) is one of the most important viral agents associated with several classes of cancers in humans. The aim of this study was to investigate HPV in esophageal cancer in the East Azerbaijan province, northwest of Iran. METHODS: 140 paraffin-embedded specimens of esophageal tissues were investigated using nested-polymerase chain reaction (nested-PCR) with primer designing for the L1 region of HPV genome. According to the pathological diagnosis, the samples were divided into two groups: 70 patients with esophageal cancer EADC (n = 35) and ESCC (n = 35) as the case group and those without tumour in esophagus tissue as a control (n = 70). RESULTS: HPV DNA was isolated from 20 (28.57%) of the 70 paraffin-embedded tissue specimens of esophagus cancer. Of these, 6 cases (17.14%) of EADC and 14 cases (40%) of ESCC were positive. In contrast, all cases of the control group were negative for the HPV genome. Sequence analysis revealed that HPV types 16 and 18 are the most frequent ones identified in this study. CONCLUSION: The prevalence of HPV in esophageal cancer can vary depending on the geographical location and other factors. Based on the findings of this study, HPV infection may possibly have contributed to an increased risk of esophageal cancer in a group of patients in Tabriz.

An Alliance of Carbapenem-Resistant Klebsiella pneumoniae with Precise Capsular Serotypes and Clinical Determinants: A Disquietude in Hospital Setting.

Carbapenemase-resistant Klebsiella pneumoniae (CRKP) is a genuine burden for physicians and researchers. We aimed at carbapenemase resistance and its relation with capsular serotyping in K. pneumoniae and studied some clinical determinants, which may influence the clinical infections. Initially, 61 K. pneumoniae isolates obtained from various clinical specimens were confirmed at the molecular level and then antimicrobial susceptibility test was performed followed by capsular serotyping performed by multiplex PCR. All isolates were subjected to the detection of carbapenemase genes including bla KPC, bla NDM-1, bla OXA-48, bla VIM, and bla IMP. Clinical and demographic data of all patients were reviewed including age, gender, underlying diseases, and the treatment obtained. Multidrug-resistance was a predominant feature in 77% K. pneumoniae strains. Presence of extended-spectrum beta-lactamase was detected phenotypically in 59% K. pneumoniae strains. Carbapenem resistance was noticed phenotypically in 24.6% isolates. bla OXA-48 and bla NDM-1 were the most frequent carbapenemase genes. bla NDM-1 positive isolates correlated with gentamicin, amikacin, imipenem, and meropenem resistance (p < 0.05). The nosocomial isolates mostly harbored bla OXA-48 gene (p < 0.02). Amongst all the K. pneumoniae isolates, 59% isolates could be typed and serotype K54 had the highest prevalence followed by K20 and K5. Correlation between the carbapenemase genes, serotype and type of infection showed that bla OXA-48 positive strains had a significant association with K20 serotype and urinary tract infections (p=0.2) while, K20 serotype and bla KPC positive strains were significantly associated with wound infections (K20, p=0.3 and bla KPC, and p=0.4). Mucoid phenotype was not found related to presence of specific carbapenemase genes or serotypes except serotype K20 (p < 0.001). Patients with monotherapy had treatment failure in comparison to the combination therapy for bla KPC-associated infections. In conclusion, the present investigation exhibited the significant association between K20 serotype with bla OXA-48. The predominance of K54 reveals the possibility of endemicity in our hospital setting. K. pneumoniae isolated from wound specimens significantly harbors K20 serotype and bla KPC gene. Comprehensive clinical information and the distribution of antibiotic resistance genes, and serotypes may play important roles in the treatment process.

Contribution of Arginine Catabolic Mobile Element and Copper and Mercury Resistance Element in Methicillin-Resistant Staphylococcus aureus: A Vantage Point.

Different clones of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are dominating geographically. One of the significant, hypervirulent, CA-MRSA and a significant health concern clones is USA3000, found worldwide regionally with varying frequencies. The clone harbors several mobile genetic elements (MGEs) including, arginine catabolic mobile element (ACME) and copper and mercury resistance genes (COMER), accomplished by horizontal gene transfer from S. epidermidis. Evidence suggests that ACME and COMER have a more prominent role in enhancing biofilm capacity and ultimately persistent infections. This review highlights the comprehensive view on ACME and COMER structure, their distribution, and the mechanism of action along with pathogenetic features of USA3000 encompassing their role in biofilm formation, adhesion, quorum sensing, resistance to antibiotics, chemotaxis, and nutrient uptake. We also provided an insight into the role of ACME and COMER genes in the survival of bacterium. Our results shed light on the emergence of two independent clones possessing ACME (North American) and COMER (South American) elements which later disseminated to other regions. ACME and COMER both are adjacent to staphylococcal cassette chromosome mec type IV (SCCmec IV). The acquisition of mecA, followed by COMER or ACME has been shown as a significant factor in the rise and fall of MRSA strains and their complex ability to adapt to hostile environments. The presence of ACME increases fitness, thereby allowing bacteria to colonize the skin and mucous membrane while COMER contributes to genetic stability by knocking over the copper-mediated killing in macrophages. Evidence suggests that ACME and COMER have a more prominent role in enhancing biofilm capacity and ultimately persistent infections. Interestingly, ACME strains have been shown to possess the ability to counteract skin acidity, thereby allowing increased skin colonization. A profound understanding of MGEs in S. aureus plays an important role in the prevention of epidemic clones.

Mucosa-Associated Escherichia coli in Colorectal Cancer Patients and Control Subjects: Variations in the Prevalence and Attributing Features.

Accumulating evidence indicates that specific strains of mucosa-associated Escherichia coli (E. coli) can influence the development of colorectal carcinoma. This study aimed to investigate the prevalence and characterization of mucosa-associated E. coli obtained from the colorectal cancer (CRC) patients and control group. At two referral university-affiliated hospitals in northwest Iran, 100 patients, 50 with CRC and 50 without, were studied over the course of a year. Fresh biopsy specimens were used to identify mucosa-associated E. coli isolates after dithiothreitol mucolysis. To classify the E. coli strains, ten colonies per sample were typed using enterobacterial repetitive intergenic consensus-based PCR (ERIC-PCR). The strains were classified into phylogroups using the quadruplex PCR method. The PCR method was used to examine for the presence of cyclomodulin, bfp, stx1, stx2, and eae-encoding genes. The strains were tested for biofilm formation using the microtiter plate assay. CRC patients had more mucosa-associated E. coli than the control group (p < 0.05). Enteropathogenic Escherichia coli (EPEC) was also found in 23% of CRC strains and 7.1% of control strains (p < 0.05). Phylogroup A was predominant in control group specimens, while E. coli isolates from CRC patients belonged most frequently to phylogroups D and B2. Furthermore, the frequency of cyclomodulin-encoding genes in the CRC patients was significantly higher than the control group. Around 36.9% of E. coli strains from CRC samples were able to form biofilms, compared to 16.6% E. coli strains from the control group (p < 0.05). Noticeably, cyclomodulin-positive strains were more likely to form biofilm in comparison to cyclomodulin-negative strains (p < 0.05). In conclusion, mucosa-associated E. coli especially cyclomodulin-positive isolates from B2 and D phylogroups possessing biofilm-producing capacity colonize the gut mucosa of CRC patients.

AdeB efflux pump gene knockdown by mRNA mediated peptide nucleic acid in multidrug resistance Acinetobacter baumannii.

Multidrug-resistant Acinetobacter baumannii isolates cause critical problems in health-care environments. AdeABC is a resistance-nodulation-cell division (RND)-type multidrug efflux pump conferring resistance to clinically essential antibiotics in A. baumannii, such as ciprofloxacin. This study aimed to target adeB gene with antisense peptide nucleic acid (PNA) and investigate its effect on resistance to antibiotics. NCBI database was used to design appropriate PNA to target adeB gene, by connecting PNA to mRNA, the translation of mRNA can be prevented. Three clinical isolates and A. baumannii ATCC 17978 were treated with the designed PNA by electroporation and competence procedure. Minimum Inhibitory concentration (MIC) of ciprofloxacin, colistin, and tetracycline were determined by microbroth dilution method. In addition, the expression level of adeB gene was measured by quantitative real-time PCR (qRT-PCR). Isolates used in this study had mutations in gyrA and parC genes corresponding to resistance to ciprofloxacin. MIC of resistance to ciprofloxacin after treatment with PNA was reduced from 32 µg/ml to16 µg/ml in A. baumannii ATCC 17978 isolate. Susceptibility level of tetracycline, in the 2 clinical isolates was decreased from 64 µg/ml to 32 µg/ml and in the other isolate was reduced from 128 µg/ml to 64 µg/ml. The expression level of adeB gene was decreased in A. baumannii ATCC 17978 (P > 0.01) but not in clinical isolate (P = 0.107). Findings of the present study indicate overexpression of adeB efflux pump has extra effect on resistance to antibiotics in isolates with a defined mechanism of resistance. Antisense technology is a feasible technique to suppress the function of these genes, which may be further exploited to control multidrug-resistant isolates.

Pilus-encoding islets in S. agalactiae and its association with antibacterial resistance and serotype distribution.

Group B Streptococcus (GBS) is a versatile organism which uses multiple virulence factors which bind to the surface of epithelial cells. Pili are one of virulence factors detected in recent years. A total of 90 isolates were collected from invasive and non-invasive isolates among adults throughout 2014-2015. Isolates were serotyped at molecular level based on capsular polysaccharide (cps) serotyping and analyzed for pilus island profiles, scpB gene, and hvgA gene presence. Isolates were subjected to antimicrobial susceptibility towards penicillin, tetracycline, erythromycin, clindamycin, moxifloxacin, levofloxacin, and vancomycin by disk diffusion method and MICs for erythromycin and clindamycin were determined by broth dilution methods. Overall, 4 serotypes were identified, serotype III (68.88%), V (20%), II (10%) and Ib (1.11%) and hvgA gene was detected in 7.7% (n = 7) of the isolates; all were serotype III/ST 17. All isolates were susceptible to penicillin and vancomycin, except one isolate which showed intermediate resistance to penicillin and other complete resistance to vancomycin. Isolates were resistant to tetracycline (98%), erythromycin (25%), clindamycin (22%), moxifloxacin (8%), and levofloxacin (6%). The scpB gene was detected in all isolates, while isolates harbored at least one PI, of which the PI-1+PI-2a was the most frequent combination observed. Our data show the presence of the relation between serotype or pilus genes among clinical isolates of Streptococcus agalactiae. These data are principal to help in designing prevention and treatment strategies for GBS infections in the region.

Effect of acidic and alkali shocks on expression of efaA gene in Enterococcus faecalis, isolated from root canal infection.

Enterococcus faecalis is an important opportunistic infectious agent involving the oral cavity and endodontics. The aim of this study was to evaluate the expression ratio of efaA gene in biofilm producer E. faecalis before and after receiving acidic and alkali shocks. One hundred E. faecalis isolates were gathered from 170 infectious root canals. After analysis of biofilm formation by the Microtiterplate method, the presence of efaA gene was examined by PCR and its expression was evaluated by Real-time PCR, one before applying any stressed to isolates and another by applying acidic and alkali shock. Chi-square method was used for statistical analysis. Eighty-two percent of samples had efaA gene. Evaluation of biofilm formation, 49% of the isolates were strong biofilm producer, 42% moderate and 10 % of them had no biofilm. 59% overexpression of efaA gene was observed in biofilm producer isolates, while there were no significant changes in samples with acidic stress and decreased expression after alkali shock. Findings of the present study, indicates importance of efaA gene in biofilm formation and pathogenesis of E. faecalis. Acid had no effect of expression of this gene but alkali reduced expression of this gene in a significant level. These results indicate the importance of efaA and acidic conditions in biofilm production by E. faecalis.

Prevalence, antimicrobial susceptibility and multiplex PCR-serotyping of Listeria monocytogenes isolated from humans, foods and livestock in Iran.

Listeria monocytogenes is a foodborne pathogen causing listeriosis, which potentially affects all individuals, especially pregnant women and immunocompromised persons. The present study investigated the prevalence, antimicrobial susceptibility and serotypes distribution of the isolated L. monocytogenes from Iran. Twenty two (4.97%) of 442 human, food and livestock samples were found to be positive for L. monocytogenes. L. monocytogenes was identified in 8.8% of 125 human samples, 2.99% of 267 food and 6% of 50 livestock samples. The standard disk diffusion method and minimum inhibitory concentration (MIC) assay were used for antimicrobial susceptibility testing and multiplex PCR for serotyping. Among the 22 isolates tested, 6 (27.2%) displayed resistance to penicillin G, with all of the isolates and 2 (9%) of them showing intermediate susceptibility to clindamycin and rifampicin, respectively. According to the MIC assay, the rate of resistance to penicillin G was the same as that of disk diffusion method, but 16 (72.7%) of isolates showed intermediate susceptibility to clindamycin using E-test. In the multiplex PCR, 19 (86.4%) of isolates belonged to serotype 1/2c or 3c and the remaining 3 isolates were identified as (4b, 4d or 4e) and (1/2a or 3a), respectively. The occurrence of resistance to penicillin G, which can be used in the treatment of listeriosis, is very alarming and more prevalence of 1/2c serotype, in comparison to 3 other important ones (1/2a, 1/2b and 4b), in Iran has been reported for the first time. To the best of our knowledge, this is the first study showing the distribution of various serogroups of L. monocytogenes from human and livestock in Iran.

Comprehensive study to investigate the role of various aminoglycoside resistance mechanisms in clinical isolates of Acinetobacter baumannii.

Therapeutic resistance towards most of the current treatment regime by Acinetobacter baumannii has reduced the prescribing antibiotic pattern and option is being re-shifted towards more toxic agents including aminoglycosides. The present investigation aimed at to study various mechanisms towards aminoglycoside non-susceptibility in clinical isolates of A. baumannii. The bacteria were subjected to genetic basis assessment for the presence of aminoglycoside modifying enzymes (AME), 16S rRNA methylase encoding genes and relative expression of AdeABC and AbeM efflux pumps in relation to their susceptibility to five aminoglycosides. When isolates were subjected to typing by repetitive extragenic palindromic (REP) PCR, isolates could be separated into thirteen definite clones. The majority of isolates (94%) were positive for AME encoding genes. Possession of ant(2')-Ia correlated with non-susceptibility towards gentamicin, amikacin, kanamycin, tobramycin; while, presence of aph(3')-VIa attributed to resistance towards amikacin, kanamycin; possession of aac(3')-Ia allied with non-susceptibility to amikacin, tobramycin and presence of aac(3')IIa correlated with kanamycin non-susceptibility. Presence of armA was detected in 34.4%, 34.2%, 29.2%, 40.3%, and 64.2% of isolates showing non-susceptibility to gentamicin, amikacin, kanamycin, tobramycin and netilmicin, respectively. No isolates were found to carry rmtB or rmtC. Amikacin non-susceptibility in comparison to other aminoglycosides correlated with over production of adeB. Overall, the results represented a definitive correlation between presence of AME encoding genes as well as armA and resistance of A. baumannii towards aminoglycosides. On the other hand, the up-regulation of AdeABC and AbeM systems was found to have only the partial role in development of aminoglycoside resistance.

Colonization of the gut mucosa of colorectal cancer patients by pathogenic mucosa-associated Escherichia coli strains.

Some strains of Escherichia coli are known to be involved in the pathogenesis of colorectal cancer (CRC). The aim of current study was to compare the general characteristics of the E. coli from CRC patients and healthy participants. A total of 96 biopsy samples from 48 CRC patients and 48 healthy participants, were studied. The clonality of the E. coli isolates was analyzed by Enterobacterial repetitive intergenic consensus-based PCR (ERIC-PCR) method. The strains were tested by PCR to determine the prevalence of different virulence factors. According to the results of ERIC-PCR analysis, (from the 860 E. coli isolates) 60 strains from CRC patients and 41 strains from healthy controls were identified. Interestingly, the majority of the strains of both groups were in the same cluster. Enteropathogenic E. coli (EPEC) was detected significantly more often in CRC patients (21.6 %) than in healthy participants (2.4 %) (p < 0.05). The Enteroaggregative E. coli (EAEC) was found in 18.33 % of the strains of CRC patients. However, other pathotypes were not found in the E. coli strains of both groups. Furthermore, all the studied genes encoding for virulence factors seemed to be more prevalent in the strains belonging to CRC patients. Among the virulence genes, the statistical difference regarding the frequency of fuyA, chuA, vat, papC, hlyA and cnf1 genes was found significant (p < 0.05). In conclusion, E. coli strains that carry extraintestinal pathogenic E. coli (ExPEC) and diarrheagenic E. coli (DEC) multiple virulence factors colonize the gut mucosa of CRC patients.

Gut microbiota in neurological diseases: Melatonin plays an important regulatory role.

Melatonin is a highly conserved molecule produced in the human pineal gland as a hormone. It is known for its essential biological effects, such as antioxidant activity, circadian rhythm regulator, and immunomodulatory effects. The gut is one of the primary known sources of melatonin. The gut microbiota helps produce melatonin from tryptophan, and melatonin has been shown to have a beneficial effect on gut barrier function and microbial population. Dysbiosis of the intestinal microbiota is associated with bacterial imbalance and decreased beneficial microbial metabolites, including melatonin. In this way, low melatonin levels may be related to several human diseases. Melatonin has shown both preventive and therapeutic effects against various conditions, including neurological diseases such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. This review was aimed to discuss the role of melatonin in the body, and to describe the possible relationship between gut microbiota and melatonin production, as well as the potential therapeutic effects of melatonin on neurological diseases.

Tuberculosis vaccine developments and efficient delivery systems: A comprehensive appraisal.

Despite the widespread use of the Bacillus Calmette-Guérin (BCG) vaccine, Mycobacterium tuberculosis (MTB) continues to be a global burden. Vaccination has been proposed to prevent and treat tuberculosis (TB) infection, and several of them are in different phases of clinical trials. Though vaccine production is in progress but requires more attention. There are several TB vaccines in the trial phase, most of which are based on a combination of proteins/adjuvants or recombinant viral vectors used for selected MTB antigens. In this review, we attempted to discuss different types of TB vaccines based on the vaccine composition, the immune responses generated, and their clinical trial phases. Furthermore, we have briefly overviewed the effective delivery systems used for the TB vaccine and their effectiveness in different vaccines.

The profile of key gut microbiota members and short-chain fatty acids in patients with sepsis.

Sepsis is a complex clinical disorder with heterogeneous etiological factors. Given its high mortality rate, it is considered a global health issue. Recently, the link between gut microbiota and their metabolites, especially short-chain fatty acids, in the pathophysiology of sepsis has been reported. However, there are few findings to confirm this relationship. This study aimed to evaluate some key gut microbiota members, pathogenic bacteria, and short-chain fatty acids in non-ICU patients with sepsis caused by bacteremia compared to a control group. In this case-control study, 45 stool samples from patients with sepsis and 15 healthy persons were collected from October 2021 to August 2022 in Tabriz, Iran. The position of some gut microbiota members and the main short-chain fatty acids concentration were assessed in the two groups by the Q-PCR and the high-performance liquid chromatography system. Faecalibacterium prausnitzii and Bifidobacterium sp. As bacterial with protective features in non-ICU patients with sepsis decreased significantly. Moreover, the concentrations of acetic acid and propionic acid significantly decreased in this group compared to the healthy volunteers. In contrast, the pathogenic bacteria members such as Enterobacteriaceae and Bacteroides sp. Increased significantly in the patients compared to the healthy individuals. The concentration of butyric acid decreased in the patients, but this change was not significant in the two groups. Protective and immune functions of F. prausnitzii and Bifidobacterium sp., as well as acetate and propionate, are evident. In this investigation, this profile was significantly reduced in non-ICU patients with sepsis compared to the control group.

Molecular Detection and Characterization of the Staphylococcus epidermidis and Staphylococcus haemolyticus Isolated from Hospitalized Patients and Healthcare Workers in Iran.

Background: The present study is aimed at surveying the antibiotics resistance profile, biofilm formation ability, staphylococcal cassette chromosome mec (SCCmec) types, and molecular epidemiology of Staphylococcus epidermidis and Staphylococcus haemolyticus isolated from hospitalized patients and healthcare workers in four teaching hospitals in Iran. Methods: In total, 43 Staphylococcus epidermidis and 12 Staphylococcus haemolyticus were isolated from hospitalized patients, and 19 Staphylococcus epidermidis and 7 Staphylococcus haemolyticus isolated from healthcare workers were included in the present study. The antimicrobial resistance profile of isolates was determined using the disk diffusion method. Moreover, the resistance of isolates to methicillin was identified using the cefoxitin disk diffusion test. The microtiter-plate test was used for quantifying biofilm formation. Moreover, the frequency of icaA and icaD genes was determined using PCR assay. The molecular epidemiology of methicillin-resistant isolates was determined using SCCmec typing and pulsed-field gel electrophoresis methods. Results: Among all coagulase-negative staphylococci isolates, the highest resistance rate (81.5%) was seen for cefoxitin and cotrimoxazole. All of the isolates were susceptible to linezolid. Out of the 66 mecA-positive isolates, the most common SCCmec type was the type I (n = 23; 34.8%) followed by type IV (n = 13; 19.7%). Using pulsed-field gel electrophoresis (PFGE) assay, 27 PFGE types including 14 common types and 13 singletons were obtained among 51 methicillin-resistant S. epidermidis (MRSE) isolates. Moreover, among 12 methicillin-resistant S. haemolyticus (MRSH) isolates, 8 PFGE types were detected, of which 5 PFGE types were singletons. Conclusion: The high rate of resistance to antibiotics as well as the possibility of cross-infection shows the importance of a pattern shift in the management and controlling programs of coagulase-negative staphylococci, especially in healthcare centers. Clinical trial registration. The present study is not a clinical trial study. Thus, a registration number is not required.

Preparation, Physicochemical Characterization, Antimicrobial Effects, Biocompatibility and Cytotoxicity of Co-Loaded Meropenem and Vancomycin in Mesoporous Silica Nanoparticles.

Mesoporous silica nanoparticles (MSNPs) have been reported as an effective system to co-deliver a variety of different agents to enhance efficiency and improve biocompatibility. This study was aimed at the preparation, physicochemical characterization, antimicrobial effects, biocompatibility, and cytotoxicity of vancomycin and meropenem co-loaded in the mesoporous silica nanoparticles (Van/Mrp-MSNPs). The prepared nanoparticles were explored for their physicochemical features, antibacterial and antibiofilm effects, biocompatibility, and cytotoxicity. The minimum inhibitory concentrations (MICs) of the Van/Mrp-MSNPs (0.12-1 µg/mL) against Staphylococcus aureus isolates were observed to be lower than those of the same concentrations of vancomycin and meropenem. The minimum biofilm inhibitory concentration (MBIC) range of the Van/Mrp-MSNPs was 8-64 µg/mL, which was lower than the meropenem and vancomycin MBICs. The bacterial adherence was not significantly decreased upon exposure to levels lower than the MICs of the MSNPs and Van/Mrp-MSNPs. The viability of NIH/3T3 cells treated with serial concentrations of the MSNPs and Van/Mrp-MSNPs were 73-88% and 74-90%, respectively. The Van/Mrp-MSNPs displayed considerable inhibitory effects against MRSA, favorable biocompatibility, and low cytotoxicity. The Van/Mrp-MSNPs could be a potential system for the treatment of infections.