Green synthesis of Ag and Cu-doped Bismuth oxide nanoparticles: Revealing synergistic antimicrobial and selective cytotoxic potentials for biomedical advancements.

BACKGROUND: Nanotechnology has emerged as a transformative realm of exploration across diverse scientific domains. A particular focus lies on metal oxide nanoparticles, which boast distinctive physicochemical attributes on the nanoscale. Of note, green synthesis has emerged as a promising avenue, leveraging plant extracts as both reduction and capping agents. This approach offers environmentally friendly and cost-effective avenues for generating monodispersed nanoparticles with precise morphologies. METHODS: In this investigation, we embarked on the synthesis of Bismuth oxide nanoparticles, both in their pure form and doped with silver (Ag) and copper (Cu). This synthesis harnessed the potential of Biebersteinia multifida extract as a versatile reducing agent. To comprehensively characterize the synthesized nanoparticles, a suite of analytical techniques was employed, including energy-dispersive X-ray spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, and Raman spectroscopy. RESULTS: The synthesized nanoparticles underwent a rigorous assessment. Their antibacterial attributes were probed, revealing a pronounced enhancement in antibiofilm activity against Pseudomonas aeruginosa and Staphylococcus aureus bacteria upon metal nanoparticle doping. Furthermore, their potential for combating cancer was scrutinized, with the nanoparticles exhibiting selective cytotoxicity towards cancer cells, U87, compared to normal 3T3 cells. Notably, among the doped nanoparticles, Cu-doped variants demonstrated the highest potency, further underscoring their promising potential. CONCLUSION: In conclusion, the present study underscores the efficacy of green synthesized Bismuth oxide nanoparticles, particularly those doped with Ag and Cu, in augmenting antibacterial efficacy, bolstering biofilm inhibition, and manifesting selective cytotoxicity against cancer cells. These findings portend a promising trajectory for these nanoparticles in the spheres of biomedicine and therapeutics. As we look ahead, a deeper elucidation of their mechanistic underpinnings and in vivo investigations are essential to fully unlock their potential for forthcoming biomedical applications.

Niosome as an Effective Nanoscale Solution for the Treatment of Microbial Infections.

Numerous disorders go untreated owing to a lack of a suitable drug delivery technology or an appropriate therapeutic moiety, particularly when toxicities and side effects are a major concern. Treatment options for microbiological infections are not fulfilled owing to significant adverse effects or extended therapeutic options. Advanced therapy options, such as active targeting, may be preferable to traditional ways of treating infectious diseases. Niosomes can be defined as microscopic lamellar molecules formed by a mixture of cholesterol, nonionic surfactants (alkyl or dialkyl polyglycerol ethers), and sometimes charge-inducing agents. These molecules comprise both hydrophilic and hydrophobic moieties of varying solubilities. In this review, several pathogenic microbes such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Plasmodium, Leishmania, and Candida spp. have been evaluated. Also, the development of a proper niosomal formulation for the required application was discussed. This review also reviews that an optimal formulation is dependent on several aspects, including the choice of nonionic surfactant, fabrication process, and fabrication parameters. Finally, this review will give information on the effectiveness of niosomes in treating acute microbial infections, the mechanism of action of niosomes in combating microbial pathogens, and the advantages of using niosomes over other treatment modalities.

The frequency of adherence, biofilm-associated, Arginine Catabolic Mobile element genes, and biofilm formation in clinical and healthcare worker coagulase-negative staphylococci isolates.

BACKGROUND: Healthcare workers may pave the way for increased infections in hospitalized patients by coagulase-negative staphylococci (CoNS). Biofilm formation and antibiotic resistance are the major problems posed by CoNS in nosocomial infections. In this study, we determined biofilm production level and the distribution of biofilm-associated and virulence genes, including icaADBC, aap, bhp, atlE, embp, and fbe, as well as IS256, IS257, mecA, and ACME clusters (arc-A, opp-3AB) among 114 clinical (n = 57) and healthcare workers (n = 57) CoNS isolates in Kerman, Iran. RESULTS: In this study, more than 80% (n = 96) of isolates were methicillin-resistant CoNS (MR-CoNS). Out of 114 isolates, 33% (n = 38) were strong biofilm producers. Strong biofilm formation was found to be significantly different between clinical and healthcare workers' isolates (P < 0.050). In addition, 28% (n = 32) of isolates were positive for icaADBC simultaneously, and all were strong biofilm producers. The prevalence of icaADBC, mecA, bhp, fbe, and IS256 in clinical isolates was higher than that in healthcare workers' isolates (P < 0.050). A significant relationship was observed between clinical isolates and the presence of icaADBC, mecA, bhp, and IS256. Although these elements were detected in healthcare workers' isolates, they were more frequent in clinical isolates compared to those of healthcare workers. CONCLUSIONS: The high prevalence of ACME clusters in healthcare workers' isolates and biofilm formation of these isolates partially confirms the bacterial colonization in the skin of healthcare workers. Isolating MR-CoNS from healthcare workers' skin through similar genetic elements to clinical isolates, such as icaADBC, mecA, and IS256, calls for appropriate strategies to control and prevent hospital infections.

Recent Advances in Nanotechnology for the Management of Klebsiella pneumoniae-Related Infections.

Klebsiella pneumoniae is an important human pathogen that causes diseases such as urinary tract infections, pneumonia, bloodstream infections, bacteremia, and sepsis. The rise of multidrug-resistant strains has severely limited the available treatments for K. pneumoniae infections. On the other hand, K. pneumoniae activity (and related infections) urgently requires improved management strategies. A growing number of medical applications are using nanotechnology, which uses materials with atomic or molecular dimensions, to diagnose, eliminate, or reduce the activity of different infections. In this review, we start with the traditional treatment and detection method for K. pneumoniae and then concentrate on selected studies (2015-2022) that investigated the application of nanoparticles separately and in combination with other techniques against K. pneumoniae.

Investigation of SARS-CoV-2 Genome in the Indoor Air and High-Touch Surfaces.

This study aimed to investigate the presence/absence of SARS-CoV-2 genome in the air and high-touch surfaces. This cross-sectional study was conducted from late-2020 to mid-2021 in the sections of Intensive Care Unit (ICU), emergency, infectious disease ward, and nursing station of the COVID-19 patient reception center in Kerman, Iran. The presence/absence of SARS-CoV-2 genome in the 60 samples of high-touch surfaces and 23 air samples was analyzed by reverse transcription polymerase chain reaction (RT-PCR). Fisher's exact test was used to compare the number of positive samples in different sampling sites. The genome of SARS-CoV-2 was found in the eight samples (13.32%) taken from the high-touch surfaces (two samples in COVID-19 ICU, two samples in general ICU, two samples in emergency ward, and two samples in nursing station) and two air samples (8.70%) (one sample in the general ICU and one sample in the emergency ward). Statistical analysis showed that there was no significant difference between the type of sampling site and the positive cases of SARS-CoV-2 in the surface samples (p value = 0.80) and air samples (p value = 0.22). According to the results, the SARS-CoV-2 can find in the high-touch surfaces and indoor air of the COVID-19 patient reception centers. Therefore, suitable safety and health measures should be taken, including regular and accurate disinfection of surfaces and equipment and proper ventilation to protect healthcare workers and prevent disease transmission. More studies are recommended to investigate the SARS-CoV-2 concentration in the high-touch surfaces and air samples in the similar researches, efficacy of different disinfectants used on the high-touch surfaces and compare the effect of type of ventilation (natural or mechanical) on the viral load.

The role of SARS-CoV-2 accessory proteins in immune evasion.

Many questions on the SARS-CoV-2 pathogenesis remain to answer. The SARS-CoV-2 genome encodes some accessory proteins that are essential for infection. Notably, accessory proteins of SARS-CoV-2 play significant roles in affecting immune escape and viral pathogenesis. Therefore SARS-CoV-2 accessory proteins could be considered putative drug targets. IFN-I and IFN-III responses are the primary mechanisms of innate antiviral immunity in infection clearance. Previous research has shown that SARS-CoV-2 suppresses IFN-ß by infecting host cells via ORF3a, ORF3b, ORF6, ORF7a, ORF7b, ORF8, and ORF9b. Furthermore, ORF3a, ORF7a, and ORF7b have a role in blocking IFNα signaling, and ORF8 represses IFNß signaling. The ORF3a, ORF7a, and ORF7b disrupt the STAT1/2 phosphorylation. ORF3a, ORF6, ORF7a, and ORF7b could prevent the ISRE promoter activity. The main SARS-CoV-2 accessory proteins involved in immune evasion are discussed here for comprehensive learning on viral entry, replication, and transmission in vaccines and antiviral development.

Molecular discrimination and antifungal susceptibility profile of cryptic Candida albicans complex species isolated from patients in Iran.

Background and Objectives: Candida albicans complex species are well known as the main cause of candidiasis, particularly among susceptible individuals. In this study, we report the genetic diversity of Candida spp. and the antifungal susceptibility pattern of the cryptic C. albicans complex isolates in Kerman, Iran. Materials and Methods: A total of 112 yeast isolates were obtained from different clinical samples, and molecular identification was performed. All C. albicans complex isolates were tested for susceptibility of them to amphotericin B, fluconazole, and itraconazole. Results: The majority of clinical isolates were C. albicans complex (n=48) followed by C. glabrata complex (n=34), C. parapsilosis complex (n=21), and C. krusei (n=9). Among C. albicans complex, 45 isolates were C. albicans (94%), 2 isolates were C. dubliniensis (4%), and 1 isolate was C. africana (2%). Amphotericin B was the most active antifungal, whereas 8.9% and 6.7% of the isolates were resistant to fluconazole and itraconazole, respectively. Conclusion: Regarding the high incidence of Candida infections particularly in susceptible populations and the emergence of an infrequent yeast species with elevated MICs, which is indistinguishable with conventional methods, developing accurate molecular methods for laboratory diagnosis should be considered in the clinical setting.

Antimicrobial and Antibiofilm Effects of Combinatorial Treatment Formulations of Anti-Inflammatory Drugs-Common Antibiotics against Pathogenic Bacteria.

With the spread of multi-drug-resistant (MDR) bacteria and the lack of effective antibiotics to treat them, developing new therapeutic methods and strategies is essential. In this study, we evaluated the antibacterial and antibiofilm activity of different formulations composed of ibuprofen (IBP), acetylsalicylic acid (ASA), and dexamethasone sodium phosphate (DXP) in combination with ciprofloxacin (CIP), gentamicin (GEN), cefepime (FEP), imipenem (IPM), and meropenem (MEM) on clinical isolates of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) as well as the transcription levels of biofilm-associated genes in the presence of sub-MICs of IBP, ASA, and DXP. The minimal inhibitory concentrations (MICs), minimal biofilm inhibitory concentrations (MBICs), and minimum biofilm eradication concentrations (MBECs) of CIP, GEN, FEP, IPM, and MEM with/without sub-MICs of IBP (200 µg/mL), ASA (200 µg/mL), and DXP (500 µg/mL) for the clinical isolates were determined by the microbroth dilution method. Quantitative real-time-PCR (qPCR) was used to determine the expression levels of biofilm-related genes, including icaA in S. aureus and algD in P. aeruginosa at sub-MICs of IBP, ASA, and DXP. All S. aureus isolates were methicillin-resistant S. aureus (MRSA), and all P. aeruginosa were resistant to carbapenems. IBP decreased the levels of MIC, MBIC, and MBEC for all antibiotic agents in both clinical isolates, except for FEP among P. aeruginosa isolates. In MRSA isolates, ASA decreased the MICs of GEN, FEP, and IPM and the MBICs of IPM and MEM. In P. aeruginosa, ASA decreased the MICs of FEP, IPM, and MEM, the MBICs of FEP and MEM, and the MBEC of FEP. DXP increased the MICs of CIP, GEN, and FEP, and the MBICs of CIP, GEN, and FEP among both clinical isolates. The MBECs of CIP and FEP for MRSA isolates and the MBECs of CIP, GEN, and MEM among P. aeruginosa isolates increased in the presence of DXP. IBP and ASA at 200 µg/mL significantly decreased the transcription level of algD in P. aeruginosa, and IBP significantly decreased the transcription level of icaA in S. aureus. DXP at 500 µg/mL significantly increased the expression levels of algD and icaA genes in S. aureus and P. aeruginosa isolates, respectively. Our findings showed that the formulations containing ASA and IBP have significant effects on decreasing the MIC, MBIC, and MBEC levels of some antibiotics and can down-regulate the expression of biofilm-related genes such as icaA and algD. Therefore, NSAIDs represent appropriate candidates for the design of new antibacterial and antibiofilm therapeutic formulations.

Nanomaterials in the Management of Gram-Negative Bacterial Infections.

The exploration of multiplexed bacterial virulence factors is a major problem in the early stages of Escherichia coli infection therapy. Traditional methods for detecting Escherichia coli (E. coli), such as serological experiments, immunoassays, polymerase chain reaction, and isothermal microcalorimetry have some drawbacks. As a result, detecting E. coli in a timely, cost-effective, and sensitive manner is critical for various areas of human safety and health. Intelligent devices based on nanotechnology are paving the way for fast and early detection of E. coli at the point of care. Due to their specific optical, magnetic, and electrical capabilities, nanostructures can play an important role in bacterial sensors. Another one of the applications involved use of nanomaterials in fighting microbial infections, including E. coli mediated infections. Various types of nanomaterials, either used directly as an antibacterial agent such as metallic nanoparticles (NPs) (silver, gold, zinc, etc.), or as a nanocarrier to deliver and target the antibiotic to the E. coli and its infected area. Among different types, polymeric NPs, lipidic nanocarriers, metallic nanocarriers, nanomicelles, nanoemulsion/ nanosuspension, dendrimers, graphene, etc. proved to be effective vehicles to deliver the drug in a controlled fashion at the targeted site with lower off-site drug leakage and side effects.

Biofilm formation and molecular analysis of intercellular adhesion gene cluster (icaABCD) among Staphylococcus aureus strains isolated from children with adenoiditis.

BACKGROUND AND OBJECTIVES: It is well known that Staphylococcus aureus biofilm plays an important role in adenoiditis and biofilm resistance frequently results in failure of therapy. The goal of this study was to evaluate the biofilm production of S. aureus isolates obtained from adenoid specimens and assess the relationship between biofilm formation ability and ica operon genes. MATERIALS AND METHODS: A total of 112 adenoid samples were obtained from patients under 15 years old with adenoid hypertrophy. All S. aureus isolates were initially identified by standard microbiological tests and amplification of nuc by polymerase chain reaction (PCR) technique. Biofilm formation of S. aureus isolates was evaluated and icaADBC genes were detected by PCR technique. RESULTS: There were 46 isolates (41%) identified as S. aureus. The ability to produce biofilm was detected among total S. aureus isolates. Molecular study of ica operon revealed that 2 (6.3%) and 19 (59.4%) isolates carried icaA and icaD, respectively. The prevalence of icaA + icaD was seen among 11 (34.4%) S. aureus isolates, while icaC and icaB were not detected. CONCLUSION: Our findings indicated that icaABCD operon are associated with biofilm formation in S. aureus isolates, however the absence of these genes may not necessarily exclude this property.

Determination of incompatibility group plasmids and copy number of the bla NDM-1 gene in carbapenem-resistant Klebsiella pneumoniae strains recovered from different hospitals in Kerman, Iran.

Introduction. New Delhi metallo-ß-lactamase (NDM)-producing Klebsiella pneumoniae has become a serious global health concern.Hypothesis/Gap Statement. Due to the high genetic diversity among NDM-positive K. pneumoniae, we need further surveillance and studies to better understand the relationships between them. In addition, the coexistence of several plasmid replicon types in NDM-positive K. pneumoniae may affect the copy number of bla NDM, the MIC level to antibiotics, as well as increasing the chance of horizontal gene transfer.Aim. The aim of this study was to determine incompatible plasmid groups and copy numbers of bla NDM, and to investigate the genetic relationship of 37 NDM-positive K. pneumoniae in Kerman, Iran.Methodology. The bla NDM-1 gene was detected and confirmed by PCR-sequencing. The plasmid replicon types were determined by PCR-based replicon typing (PBRT) and the copy number of bla NDM-1 was determined by quantitaive real time-PCR (qPCR). Random amplified polymorphic DNA (RAPD)-PCR typing was used to detect genetic relationships between the strains.Results. In this study, 10 different replicon types, including Frep [n=25 (67.5 %)], FIIAs [n=11 (29.7 %)], FIA [n=5 (13.5 %)], FIB [n=3 (8.1 %)], I1-Iγ [n=2 (5.4 %)], L/M [n=7 (18.9 %)], A/C [n=7 (18.9 %)], Y [n=3 (8.1 %)], P [n=1 (2.7 %)] and FIC [n=1 (2.7 %)] were reported. The copy numbers of the bla NDM-1 gene varied from 30.00 to 5.0×106 and no statistically significant correlation was observed between a rise of the MIC to imipenem and the copy numbers of bla NDM-1 (P>0.05). According to RAPD typing results, 35 strains were divided into five clusters, while two strains were non-typeable.Conclusion. The spread of NDM-1-producing K. pneumoniae strains that carry several plasmid replicon types increases the chance of horizontal transfer of antibiotic resistance genes in hospital settings. In this study, 10 different replicon types were identified. We could not find any relationship between the increase of MIC levels to imipenem and the copy numbers of bla NDM-1. Therefore, due to the identification of different replicon types in this study, the type and genetic characteristics of bla NDM-1-carrying plasmids, and other factors such as antibiotic selective pressure, probably affect the copy number of bla NDM-1 and change the MIC level to imipenem.

Comparison five primer sets from different genome region of COVID-19 for detection of virus infection by conventional RT-PCR.

BACKGROUND AND OBJECTIVES: The new beta-coronavirus, which caused Severe Acute Respiratory Coronavirus-2 Syndrome (SARS-CoV-2), a major respiratory outbreak in Wuhan, China in December 2019, is now prevalent in many countries around the world. Identifying PCR-based viruses is a well-known and relatively stable protocol. Unfortunately, the high mutation rates may lead to widespread changes in viral nucleic acid sequences, and so using specific primers for PCR can be recommended. In this study, we evaluated the power of a conventional RT-PCR to detect SARS-CoV-2 RNA among the five set primer sets. MATERIALS AND METHODS: The five genomic regions of the Coronavirus SARS-2 virus including Nucleocapsids (N), Envelope (E), RNA depended RNA Polymerase (RdRp), ORF1ab and Spike (S) were selected for primer designing. A conventional RT-PCR was performed to compare sensitivity, specificity and other analytical characteristics of primers designed against two Real Time PCR commercial kits. RESULTS: The result of the comparative analysis showed that the ORF1ab, N and RdRp primers had a sensitivity, specificity and positive predictive value higher than other primers. A significant difference in the analytical sensitivity between the studied primer sets in RT-PCR kits was observed. CONCLUSION: In this study, the ORF1ab, Nucleocapsid and RdRp regions have the best primers for identifying the SARS-CoV-2 RNA between different genes that have been suggested.

In vitro Reducing Effect of Cloxacillin on Minimum Inhibitory Concentrations to Imipenem, Meropenem, Ceftazidime, and Cefepime in Carbapenem-resistant Pseudomonas aeruginosa Isolates.

Today, resistance to antibacterial agents is the most important problem facing public health. Pseudomonas aeruginosa is a common gram-negative bacterium and an important cause of nosocomial infections. Resistance to many antibiotics in strains of P. aeruginosa isolated from hospital settings such as cephalosporins and carbapenems have been recently reported. Therefore, the introduction of a new strategy to treat the infection of these organisms will be beneficial. In this study we determined the ability of cloxacillin to reduce Minimum Inhibitory Concentrations (MICs) of carbapenem-resistant P. aeruginosa to imipenem (IMI), meropenem (MEM), ceftazidime (CAZ), and cefepime (FEP). From 2015 to 2017, 61 non-duplicates of carbapenem-resistant P. aeruginosa were collected from clinical samples of hospitalized patients in Kerman, Iran. The MICs of the isolates to IMI, MEM, CAZ, and FEP with/without cloxacillin were determined by microbroth dilution method. The level of MIC of isolates to carbapenems (IMI and MEM) and cephalosporins (CAZ and FEP) ranged from 1-256 µg/mL and 4-1024 µg/mL alone and from 1-32 µg/mL and 1-512 µg/mL in combination with cloxacillin, respectively. The MIC showed a significant difference reduction after the addition of cloxacillin (P ≤ 0.05). Our results showed in vitro potentially of cloxacillin in reduction of MIC to IMI, MEM, CAZ, and FEP in multi-drug resistant P. aeruginosa, therefore combination of these antibiotics with cloxacillin could be beneficial for treatment of infections caused by multi-drug resistant P. aeruginosa.

Determining spa-type of methicillin-resistant Staphylococcus aureus (MRSA) via high-resolution melting (HRM) analysis, Shiraz, Iran.

OBJECTIVES: Molecular typing methods are useful for rapid detection and control of a disease. Recently, the use of high-resolution melting (HRM) for spa typing of MRSA isolates were reported. This technique is rapid, inexpensive and simple for genotyping and mutation screening in DNA sequence. The aim of this study was to evaluate the ability of HRM-PCR to analysis spa genes amongst MRSA isolates. RESULTS: A total of 50 MRSA isolates were collected from two teaching hospitals in Shiraz, Iran. The isolates were confirmed as MRSA by susceptibility to cefoxitin and detection of mecA gene using PCR. We used HRM analysis and PCR-sequencing method for spa typing of MRSA isolates. In total, 15 different spa types were discriminate by HRM and sequencing method. The melting temperature of the 15 spa types, using HRM genotyping were between 82.16 and 85.66 °C. The rate of GC % content was 39.4-46.3. According to the results, spa typing of 50 clinical isolates via PCR-sequencing and HRM methods were 100% similar. Consequently, HRM method can easily identify and rapidly differentiate alleles of spa genes. This method is faster, less laborious and more suitable for high sample at lower cost and risk of contamination.

Dissemination of different sequence types lineages harboring bla CTX-M-15 among uropathogenic Escherichia coli in Kerman, Iran.

OBJECTIVES: Escherichia coli is one of the most important causes of urinary tract infections (UTIs). The aim of this study was to determine antimicrobial resistance, resistance and virulence genes; phylogenetic groups and identify the epidemiologic features of uropathogenic E. coli (UPEC) isolates by multilocus sequence typing (MLST). MATERIALS AND METHODS: One hundred isolates of E. coli from inpatients with UTIs were collected in Kerman, Iran. Antimicrobial susceptibility testing, ESBLs, AmpC production and biofilm formation were performed by phenotypic methods. Phylogenetic groups, resistance and virulence genes were detected. Molecular typing of isolates was performed by MLST. RESULTS: In this study, 76% of isolates were multidrug-resistant. The bla CTX-M-15 and bla TEM were the dominant ESBL-encoding gene. Among 63 ciprofloxacin-resistant isolates, the frequency of qnrS (15.8%), qnrB (9.5%), and aac (6')-Ib (25% ) genes was shown. Fifty-five present of isolates were classified as week biofilm, (14%) moderate biofilm, and (5%) strong. The predominant phylogenetic group was B2 (3) . The prevalence of virulence genes ranged fimH (93%), iutA (66%), KpsmtII (59%), sat (39%), cnf (28%) and hlyA (27%). According to MLST results, 14 sequence types (ST) including ST-693, ST-90, ST-101, ST-1664, ST-2083, ST-131, ST-4443, ST-744, ST-361, ST-405, ST-922, ST-648, ST-5717and ST-410 were detected, indicating a high degree of genotypic diversity. CONCLUSION: We identified a high frequency of the ST131 clonal group among UTIs. These data show an important public health threat, and so further studies to control the dissemination and risk factors for acquisition of the ST131 clonal group and other STs are needed to make effective control.

Virulence Factors, Capsular Serotypes and Antimicrobial Resistance of Hypervirulent Klebsiella pneumoniae and Classical Klebsiella pneumoniae in Southeast Iran.

BACKGROUND: The present study was conducted to investigate the distribution of virulence factors, capsular serotypes and antibiotic resistance properties of classical Klebsiella pneumoniae (cKP) and hypermucoviscous/hypervirulent Klebsiella pneumoniae (hvKP) isolated from different clinical specimens in Kerman, south-east of Iran. MATERIALS AND METHODS: A total of 146 K. pneumoniae isolates were obtained from different clinical specimens. HvKP isolates were identified using the string test. Genes of capsular serotypes K1, K2, K5, K20, K54 and K57 and virulence-associated genes, rmpA, kfu, fimH, mrkD, allS, iutA, magA, entB and ybtS were evaluated by PCR. Antimicrobial susceptibility was also determined using the disc diffusion method. RESULTS: Out of 146 K. pneumoniae isolates, 22 (15.1 %) were hvKP. More than half of the hvKP isolates, 13 (59.1%), belonged to non-K1, K2, K5, K20, K54, K57 serotypes. Out of 22 hvKP isolates, 3 and 3 had K1 and K2 serotypes respectively. Among all isolates, entB 140 (95.9%) and mrkD 138 (94.5%) were the most common virulence genes. RmpA, iutA and kfu were associated with hvKP isolates (P-value <0.05). However, no significant difference was found in fimH, allS, mrkD, entB and ybtS genes between hvKP and cKP strains. HvKP exhibited significantly lower resistance rates to all antimicrobial agents than cKP, except to trimethoprim-sulphamethoxazole and ampicillin (P-value <0.05). CONCLUSION: The frequency of hvKP was low, but overall, the prevalence of virulence-related genes was higher in hvKP than cKP. HvKP was not related to specific serotypes. Furthermore, hvKP isolates were more susceptible to antimicrobial agents compared to cKP isolates.

Characterization of SCCmec, spa types and Multi Drug Resistant of methicillin-resistant Staphylococcus aureus isolates among inpatients and outpatients in a referral hospital in Shiraz, Iran.

OBJECTIVES: Molecular typing such as spa typing is used to control and prevent Staphylococcus aureus widespread in hospitals and communities. Hence, the aim of this study was to find the most common types of S. aureus strain circulating in Shiraz via spa and SCCmec typing methods. RESULTS: Total of 159 S. aureus isolates were collected from two tertiary hospitals in Shiraz. Isolates were identified by biochemical tests. Antimicrobial susceptibility tests were performed by standard disk diffusion method and then genetic analysis of bacteria was performed using SCCmec and spa typing. In this study 31.4% of the isolates were methicillin-resistant S. aureus. The majority of isolates were SSCmec type III. Spa type t030 was the most prominent type among MRSA strains. For the first time in Iran, spa003, t386, t1877, t314, t186, t1816, t304, t325, t345 were reported in this study. It was shown that there is a possibility that these spa types are native to this region. Our findings showed that SCCmec II, III and IV disseminate from hospital to community and vice versa. Thus, effective monitoring of MRSA in hospital and community is necessary.

Molecular analysis and antimicrobial resistance pattern of distinct strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients in Iran.

BACKGROUND AND OBJECTIVES: Colonization of Pseudomonas aeruginosa in Cystic Fibrosis (CF) patients may lead to severe pulmonary disease and death. Different characteristics of P. aeruginosa from these patients were determined in the present study. MATERIALS AND METHODS: Antimicrobial susceptibility and AmpC-overproduction were determined. The ß-lactamase genes were detected by PCR and the oprD gene was sequenced in some of the carbapenem resistance isolates. Distribution of exo genes was determined by PCR. Cytotoxicity of Exo effector proteins was measured using A549 cells. Biofilm production was determined by microtiter plate assay. Random amplified polymorphic DNA (RAPD) -PCR was performed for molecular analysis. RESULTS: Polymyxin B, piperacillin/tazobactam and meropenem were the most active antibiotics and 9.6% of isolates were ampC overproducers. The prevalence of bla VEB, bla OXA, bla VIM, and bla PER genes were as follow: 22.7%, 3.75%, 6.25% and 3.75%, respectively. A high proportion (83.5%) of isolates was able to produce biofilm. The exoT gene was present in all isolates while exoU was present in about 35% of them. RAPD-PCR revealed 49 patterns among 78 tested isolates in which 34 patterns were detected once. CONCLUSION: Biofilm formation ability and relatively high frequency of exoS may contribute to the persistence of bacteria within lungs of CF patients. Some characteristics of isolates recovered from a single patient after several sampling procedures were similar, while others lacked resemblance.

Identification of Candida spp. isolated from oral mucosa in patients with leukemias and lymphomas in Iran.

BACKGROUND AND OBJECTIVES: Oral candidiasis is a serious problem for immunocompromised patients, especially patients with hematological malignancies. After becoming a systemic candidiasis it is difficult to diagnose, control and treat in individuals with hematological malignancies. The aim of this study was to diagnose candidiasis in the oral mucosa of patients with leukemias and lymphomas in a timely manner in order to prevent their progression to systemic candidiasis. MATERIALS AND METHODS: In this cross sectional study, 50 clinical samples were collected from the mouth of patients with hematological malignancies undergoing chemotherapy from the oncology units of teaching hospitals in Kerman, Iran. Patients were from Kerman, Sistan-Baluchestan and Hormozgan in south-eastern Iran. Sampling was restricted to patients with diagnosed acute lymphoid leukemia (ALL); acute myeloid leukemia (AML); chronic lymphoid leukemia (CLL); chronic myeloid leukemia (CML); Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). Presumptive species identification of fungi was performed using conventional methods like colony characteristics on CHROMagar Candida medium, germ tube production, and assessing the morphology fungi on corn meal agar. Confirmation of presumptive candida isolates was performed using PCR-RFLP. RESULTS: From a total of 50, 14 patients (28%) had positive oral candidiasis. Candida albicans (57.14%) was the most common species followed by Candida glabrata (14.28%), Candida parapsilosis (14.28%), Candida krusei (7.14%) and Candida kefyr (7.14%). Candida albicans had the highest rate of oral infection in ALL (35.71%) and then NHL (28.57%) patients. CONCLUSION: The results indicate that oral candidiasis is a prevalent fungal infection in the patients with hematologic malignancies with C. albicans being the main etiological agent. However, other species of Candida cause similar infections in these patients.

Genetic characterization of two vancomycin-resistant Staphylococcus aureus isolates in Kerman, Iran.

AIM: The aim of this study was the genetic characterization of two clinical vancomycin-resistant Staphylococcus aureus (VRSA) isolates. MATERIALS AND METHODS: Resistance to vancomycin was determined by phenotypic method. PCR was used for detection of mecA, vanA, ermA, ermB, ermC, msrA/B, aph(2")-Ic, aph(3')-IIIa, pvl, Immune Evasion Cluster [sea, sep, chip, sak and scn] genes and biofilm operon icaABCD. On the other hand, multilocus sequence typing and agr typing methods were performed for the determination of clonal relationship and van operon was detected and sequenced. RESULTS: Vancomycin-resistant Staphylococcus aureus strain 1 (VRSA-1) was positive for vanA, ermA, ermC, aph(2")-Ic, aph(3')-IIIa, sea, sep, icaD genes, belonging to agr type I; SCCmec type III; spa type t030; and ST239. However, the genetic characterization of Vancomycin-resistant Staphylococcus aureus strain 2 (VRSA-2) revealed the presence of various types of resistance genes vanA, ermA, ermC, aph(2")-Ic, aph(3')-IIIa, sea, icaD, relating to agr type I; SCCmec type III; spa type t459; and ST239. The presence of transposon Tn1546 was determined by PCR sequencing.The Basic Local Alignment Search Tool analysis of van operon in the VRSA isolates showed 99.6% sequence homology to Tn1546 in vancomycin-resistant enterococci, indicating the vanA operon has an enterococcal origin. CONCLUSION: In conclusion, the ST239 is one of the most common clones of MRSA isolates which involved the hospital-associated infections, therefore, the emergence of VRSA isolates with ST239 increased the spread of resistance to vancomycin in the hospital settings.