Higher Minimum Inhibitory Concentration Values Research Articles

Antimycobacterial, Enzyme Inhibition, and Molecular Interaction Studies of Psoromic Acid in Mycobacterium tuberculosis: Efficacy and Safety Investigations.

The current study explores the antimycobacterial efficacy of lichen-derived psoromic acid (PA) against clinical strains of Mycobacterium tuberculosis (M.tb). Additionally, the inhibitory efficacy of PA against two critical enzymes associated with M.tb, namely, UDP-galactopyranose mutase (UGM) and arylamine-N-acetyltransferase (TBNAT), as drug targets for antituberculosis therapy were determined. PA showed a profound inhibitory effect towards all the M.tb strains tested, with minimum inhibitory concentrations (MICs) ranging between 3.2 and 4.1 µM, and selectivity indices (SIs) ranging between 18.3 and 23.4. On the other hand, the standard drug isoniazid (INH) displayed comparably high MIC values (varying from 5.4 to 5.8 µM) as well as low SI values (13.0–13.9). Interestingly, PA did not exhibit any cytotoxic effects on a human liver hepatocellular carcinoma cell line even at the highest concentration tested (75 µM). PA demonstrated remarkable suppressing propensity against UGM compared to standard uridine-5'-diphosphate (UDP), with 85.8 and 99.3% of inhibition, respectively. In addition, PA also exerted phenomenal inhibitory efficacy (half maximal inhibitory concentration (IC50) value = 8.7 µM, and 77.4% inhibition) against TBNAT compared with standard INH (IC50 value = 6.2 µM and 96.3% inhibition). Furthermore, in silico analysis validated the outcomes of in vitro assays, as the molecular interactions of PA with the active sites of UGM and TBNAT were unveiled using molecular docking and structure–activity relationship studies. Concomitantly, our findings present PA as an effective and safe natural drug plausible for use in controlling tuberculosis infections.

Effect of Extracts of Capparis spinosa, Withania somnifera and Peganum harmala on Aspergillus flavus Growth and Expression of Major Genes in Aflatoxin Biosynthetic Pathway

Background: Aflatoxins, a polyketide group derived from furanocoumarins, are highly toxic carcinogens produced by Aspergillus flavus and other closely related species. Objectives: In this research, the effects of Capparis spinosa, Withania somnifera, and Peganum harmala extracts on A. flavus growth and the expression of some major genes in aflatoxin biosynthetic pathway were investigated. Methods: Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were measured and the expression of aflQ, aflO, aflS, and aflR genes was evaluated by using quantitative real-time polymerase chain reaction (qRT-PCR) technique. Results: Capparis spinosa extract had the lowest MIC value (200 mg/mL) and the extracts of W. somnifera and P. harmala had the highest MIC value (400 mg/mL). The extracts of W. somnifera and P. harmala had no fungicidal activity, and the C. spinosa extract had the lowest MFC value (400 mg/mL) and had the highest fungicidal effect on A. flavus. The expression of aflQ, aflO, aflS, and aflR genes was significantly decreased by the C. spinosa extract. Conclusions: In general, the C. spinosa extract could have fungicidal and inhibitory effects on A. flavus and reduce expression of major genes in the aflatoxin biosynthetic pathway.

Antimicrobial Susceptibility of Environmental Non-O1/Non-O139 Vibrio cholerae Isolates.

Vibrio cholerae serogroups O1 and O139 are the causative agents of cholera disease. There are more than 200 serogroups in this species that are termed V. cholerae non-O1/non-O139. Non-O1/non-O139 strains can cause gastroenteritis and cholera like diarrhea, wound infections, external otitis, and bacteraemia that may lead to mortality. Previous antimicrobial susceptibility studies were conducted mainly on O1/O139 serogroups and on clinical isolates. Our aim was to study and compare the antimicrobial susceptibilities of non-O1/non-O139 environmental strains isolated from chironomids, fish, and waterfowl. Significant differences were found in the antimicrobial susceptibilities between the environmental strains that were isolated from three different reservoir habitats. Significant increase in minimum inhibitory concentrations (MICs) of ampicillin and chloramphenicol was found in chironomid isolates from 2009 compared to those from 2005. V. cholerae isolates from different waterfowl species displayed the highest MIC values to chloramphenicol and trimethoprim-sulfamethoxazole (SXT), while chironomid isolates demonstrated the highest MIC values toward ampicillin. Isolates from fish and waterfowl showed high MIC values toward doxycycline. No significant differences were found between the MICs of isolates from the different waterfowl species. The percentage of antimicrobial resistance among V. cholerae isolates from waterfowl was the highest compared to the abundance of antimicrobial resistant isolates from chironomids or fish. The antimicrobial resistance genes can be carried on mobile genetic elements, thus, waterfowl may act as reservoirs for these elements and may spread them all over the globe. Data regarding treatment with antimicrobial agents toward V. cholerae non-O1/non-O139 serogroups is lacking and therefore further studies are needed.

Characterization of Bacterial Communities and Their Antibiotic Resistance Profiles in Wastewaters Obtained from Pharmaceutical Facilities in Lagos and Ogun States, Nigeria.

In Nigeria, pharmaceutical wastewaters are routinely disseminated in river waters; this could be associated with public health risk to humans and animals. In this study, we characterized antibiotic resistant bacteria (ARB) and their antibiotic resistance profile as well as screening for sul1 and sul2 genes in pharmaceutical wastewater effluents. Bacterial composition of the wastewater sources was isolated on non-selective media and characterized by the polymerase chain reaction (PCR) amplification of the 16S rRNA genes, with subsequent grouping using restriction fragment length polymorphism (RFLP) and sequencing. The antibiotics sensitivity profiles were investigated using the standard disk diffusion plate method and the minimum inhibitory concentrations (MICs) of selected antibiotics on the bacterial isolates. A total of 254 bacterial strains were isolated, and majority of the isolates were identified as Acinetobacter sp., Klebsiella pneumonia, Proteus mirabilis, Enterobacter sp. and Bacillus sp. A total of 218 (85.8%) of the bacterial isolates were multidrug resistant. High MICs values were observed for all antibiotics used in the study. The result showed that 31.7%, 21.7% and 43.3% of the bacterial isolates harbored sul1, sul2, and Intl1 genes, respectively. Pharmaceuticals wastewaters are potential reservoirs of ARBs which may harbor resistance genes with possible risk to public health.

Antimicrobial susceptibilities and molecular typing of neisseria gonorrhoeae isolates at a medical centre in Taiwan, 2001–2013 with an emphasis on high rate of azithromycin resistance among the isolates

A high prevalence of gonococcal resistance to various antimicrobials and Neisseria gonorrhoeae isolates exhibiting resistance to extended-spectrum cephalosporins have been reported in the past few decades. A total of 226 N. gonorrhoeae isolates obtained from the National Taiwan University Hospital from 2001 to 2013 were evaluated. The minimum inhibitory concentrations (MICs) of the isolates to antimicrobials were determined by the agar dilution method and interpreted using the 2017 clinical breakpoints or epidemiological cut-off values recommended by the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST). The genetic relatedness of these isolates was determined by multilocus sequence typing. None of the isolates was resistant to ceftriaxone and cefotaxime, and the resistance rates to cefixime, spectinomycin, cefpodoxime, ciprofloxacin, and penicillin were 0.4%, 0.4%, 13.3%, 91.6%, and 87.6%, respectively. The rate of isolates resistant to azithromycin was 14.6% (EUCAST criteria), which is higher than in previous surveillance studies. A total of 57 sequence types (ST) were identified, and ST1901, ST7365, and ST1927 prevailed. Isolates of ST8143 emerged after 2011. ST1901 isolates had relatively higher MIC values for ceftriaxone and azithromycin than those of the other STs. In conclusion, ceftriaxone remains an effective drug of choice for gonorrhoeal management in Taiwan. High rates of azithromycin resistance among N. gonorrhoeae isolates were found. The circulating ST1901 strains with high MIC values for ceftriaxone and azithromycin and the emerging ST8143 strains were alarming.

Evaluation of Antibacterial Activity of Cinnamomum Zeylanicum Extract on Cariogenic Microorganisms of the Dental Plaque In-Vitro Study and Scanning Electron Microscopic Assessment

The present study was conducted to evaluate the antibacterial activity of Cinnamomum zeylanicum aqueous extracts and ethanol extracts on different type of dental plaque microorganisms. Screening study was performed to detect the potential antibacterial activity against S. aureus, E. coli, S. mutans, Lactobacillus and dental plaque pool samples. From the screening test, Minimum Inhibitory Concentration (MIC) values were determined. The lowest MIC value was 25 mg/ml of aqueous and 12.5 mg/ml of ethanol extract for S. aureus. The highest MIC values were seen in dental plaque anaerobic pool samples with 300 mg/ml of aqueous extract and 150 mg/ml of ethanol extract. The MIC values for aqueous extracts ranged from 25 to 300 mg/ml where as ethanol extract ranged from 12.5 to 150 mg/ml. The high concentration of ethanol extract, 100 mg/ml in the fixed plant concentration test showed the most inhibition effect for all the organisms tested. Generally, the Cinnamomum zeylanicum ethanol extracts demonstrated a stronger antibacterial activity compared to the aqueous extract. This study also compares the antibacterial activity of chlorhexidine with the plant extracts but chlorhexidine showed a higher antibacterial effect on the microorganisms where almost all organisms inhibited The morphological structures of S. mutans Lactobacillus were observed under SEM before and after treatment with Cinnamomum zeylanicum extracts and chlorhexidine digluconate mouthwash. This study did not detect any physical changes occurring in shapes and structures of the bacteria after treatment with Cinnamomum zeylanicum extracts. The scanning electron micrograph of bacteria after treatment with chlorhexidine digluconate mouthwash showed visible changes in the shapes and structures of the bacteria. Cinnamomum zeylanicum present promising antibacterial properties which could be used to inhibit dental plaque formation

Two cases of fungal keratitis caused by Metarhizium anisopliae

We present two cases of keratitis due to Metarhizium anisopliae in geographically separated areas of the United States. The isolates were microscopically similar but morphologically different and were identified by ribosomal DNA sequencing. Both isolates had low minimum inhibitory concentration (MIC) values to caspofungin and micafungin, but high MIC values to amphotericin B. The morphologic and antifungal susceptibility differences between the two isolates indicate possible polyphylogeny of the group.

23S rRNA and L22 ribosomal protein are involved in the acquisition of macrolide and lincosamide resistance in Mycoplasma capricolum subsp. capricolum

Mycoplasma capricolum subsp. capricolum (Mcc) is one of the causative agents of contagious agalactia, and antimicrobial therapy is the most commonly applied measure to treat outbreaks of this disease. Macrolides and lincosamides bind specifically to nucleotides at domains II and V of the 23S rRNA. Furthermore, rplD and rplV genes encode ribosomal proteins L4 and L22, which are also implicated in the macrolide binding site. The aim of this work was to study the relationship between mutations in these genes and the acquisition of macrolide and lincosamide resistance in Mcc. For this purpose, in vitro selected resistant mutants and field isolates were studied. This study demonstrates the appearance of DNA point mutations at the 23S rRNA encoding genes (A2058G, A2059G and A2062C) and rplV gene (Ala89Asp) in association to high minimum inhibitory concentration values. Hence, it proves the importance of alterations in 23S rRNA domain V and ribosomal protein L22 as molecular mechanisms responsible for the acquisition of macrolide and lincosamide resistance in both field isolates and in vitro selected mutants. Moreover, these mutations enable us to provide an interpretative breakpoint of antimicrobial resistance for Mcc at MIC 0.8 μg/ml.

A Questionnaire-based Survey of Physician Perceptions of the Prevalence of Antimicrobial Resistance and Their Antibiotic Prescribing Patterns.

Background:Antibiotic resistance is a serious problem being faced by physicians worldwide. This article was designed to study physician perceptions of antibiotic resistance and their prescribing patterns.Materials and Methods:A structured questionnaire was developed for reporting the prevalence of antibiotic resistance as perceived by physicians and recording their antibiotic preferences in specific contexts. A total of 539 intensivists across India participated in the study.Results:The prevalence of multidrug-resistant (MDR) Gram-negative pathogens was reported to be on the rise in Intensive Care Units. The prevalence rate of carbapenem-resistant Enterobacteriaceae was reported to be between 20% and 40% by 33% of the participants. Piperacillin-tazobactam was the preferred beta-lactam/beta-lactamase inhibitor antibiotic by the majority of intensivists (47%) in the treatment of infections caused by extended-spectrum beta-lactamase producers. Meropenem was recommended to be used at a higher dose (2 g t.i.d.) by 41% of intensivists for Pseudomonas/Acinetobacter infections with high minimum inhibitory concentration values for meropenem. De-escalation data revealed that 43% of intensivists “always” would like to de-escalate from carbapenems, based on the antibiotic susceptibility data. Minocycline was recommended by 33% for the treatment of ventilator-associated pneumonia (VAP) and by 21% for bloodstream infections caused by MDR Acinetobacter. Up to 83% of intensivists preferred the use of nebulized colistin for the management of VAP/hospital-acquired pneumonia.Conclusion:This study reveals that the prevalence of MDR Gram-negative pathogens is perceived to be on the rise. Prescription patterns indicate high levels of variability. Hence, antibiotic stewardship is essential to standardize antibiotic prescriptions not only for efficacy but also to reduce the burden of multiple drug resistance.

Pharmacokinetics of chloramphenicol (CAP) in gilthead sea bream (Sparus aurata) and its in vitro activities against important bacterial fish pathogens

The pharmacokinetics of chloramphenicol (CAP) in gilthead sea bream (Sparus aurata), a warm water farmed fish species and its in vitro efficacy against important bacterial diseases of Mediterranean mariculture were investigated in this study. After an intravascular injection (10 mg/kg/fish), the distribution half-life (tl/2a) and the elimination half-life (tl/2ß) of CAP were calculated to be 1.6 and 69 h, respectively. Tissue penetration of CAP was found to be moderate since both the apparent volume of distribution of the drug at steady-state (V<i(ss)) and the apparent volume of the central compartment (Vc) were calculated to be 1.13 and 0.90 L/kg. The total clearance (CLp) of the drug was slow (0.022 L/kg/h). The minimum inhibitory concentration (MIC) values of CAP in distilled water supplemented with 2% NaCl against Vibrio anguillarum serotype lb, Photobacterium damsela subsp. piscicida, V alginolyticus and V ßuvialis were determined to be 4.78 pg/mL, while it was 0.60 pg/mL for V. damsela. The addition of 10 mM Ca2+ and 55 mM Mg2+ in the medium revealed MIC values of 19.13 pg/mL for V alginolyticus and V ßuvialis, whereas showed no effect for V anguillarum P. damsela subsp. Piscicida and V damsela. The results indicate that CAP displayed a satisfactory kinetic profile and it is eliminated fast from gilthead sea bream muscle; however, its high MIC values stress show a possible inefficacy against important bacterial pathogens of Mediterranean mariculture.

Chromium bioremediation by Alcaligenes sp. strain newly isolated from chromite mine of Sabzevar

In this work, CKCr-6A strain was found to be highly resistant to some toxic heavy metals such as Cr+6, Cr+3, Cu+2, Co+2, Cd+2, Pb+2, Hg+2, U+6, tellurium, and selenite. Herein, high chromate tolerance of an isolated strain is reported with a high minimum inhibitory concentration value of 80,000 mg/L and the effective parameters (pH, temperature, shaking, and glucose concentration) were selected for Cr(VI) removal by this isolated strain. Cr(VI) elimination by the target strain increased with glucose addition to the culture medium. We optimized the possible parameters and their interactions using design experimental software. After optimization, this strain showed high efficiency in detoxifying chromate; this could reduce up to 100 mg/L of Cr(VI) to Cr(III) over 3 h. The CKCr-6A strain exhibited ability to in vitro reduction after 3 h and repeated removing of Cr(VI) without any amendment of nutrients, suggesting its possible application in continuous bioremediation.

Isolation of Rhodotorula mucilaginosa from blood cultures in a tertiary care hospital.

Rhodotorula species have traditionally been considered as one of common non-virulent environmental inhabitant. They have emerged as an opportunistic pathogen, particularly in immunocompromised hosts and most infections have been associated with intravenous catheters in these patients. We review the isolates in blood cultures of Rhodotorula mucilaginosa in our Hospital. We describe the demographic and clinical features of the cases and the antifungal susceptibility profiles of the isolates. Selected patients had an isolation of R.mucilaginosa in blood cultures in our tertiary care Hospital. All data were collected retrospectively from clinical records during 5years. We report 8 isolates in blood, two of them were considered contaminants. Immunosuppression, surgery, previous antibiotic therapy were common clinical features. For all the isolates, minimum inhibitory concentration (MIC) values were high for echinocandins and azoles and low for amphotericin B and 5-flucytosine. One strain showed atypical susceptibility profile. Rhodotorula mucilaginosa may be present on the skin and blood cultures can be contaminated. Fungaemia due to R.mucilaginosa is a rare clinical entity which requires risk factors but clinically relevant because of the multiresistant profile. Rhodotorula mucilaginosa shows high MIC values for azoles and echinocandins, therefore amphotericin B and flucytosine must be administered as antifungal therapy.

In Vitro Activity of Calcium Channel Blockers in Combination with Conventional Antifungal Agents Against Clinically Important Filamentous Fungi

Despite the current therapeutic options, filamentous fungal infections are associated with high mortality rate especially in immunocompromised patients. In order to find a new potential therapeutic approach, the in vitro inhibitory effect of two antiarrhythmic agents, diltiazem and verapamil hydrochloride were tested against different clinical isolates of ascomycetous and mucoralean filamentous fungi. The in vitro combinations of these non-antifungal drugs with azole and polyene antifungal agents were also examined. Susceptibility tests were carried out using the broth microdilution method according to the instructions of the Clinical and Laboratory Standards Institute document M38-A2. Checkerboard microdilution assay was used to assess the interactions between antifungal and non-antifungal drugs. Compared to antifungal agents, diltiazem and verapamil hydrochloride exerted a relatively low antifungal activity with high minimal inhibitory concentration values (853–2731 μg/ml). Although in combination they could increase the antifungal activity of amphotericin B, itraconazole and voriconazole. Indifferent and synergistic interactions were registered in 33 and 17 cases, respectively. Antagonistic interactions were not revealed between the investigated compounds. However, the observed high MICs suggest that these agents could not be considered as alternative systemic antifungal agents.

Pilot Study of Antimicrobial Resistance in Northern Bobwhites (Colinus virginianus).

Antimicrobial resistance (AMR) is an important issue for both wildlife conservation and public health. The purpose of this study was to screen for AMR in fecal bacteria isolated from northern bobwhite (Colinus virginianus), a species that is an ecologically and economically important natural resource in the southern United States. The antimicrobial susceptibility profiles of 45 Escherichia coli isolates, 20 Enterococcus faecalis isolates, and 10 Enterococcus faecium isolates were determined using the SensititerTM microbroth dilution minimum inhibitory concentration (MIC) plate, AVIAN1F. Overall, E. coli isolates had high MIC values for the following classes of antimicrobials: aminocoumarins, beta-lactams, lincosamides, macrolides, florfenicol, and sulfonamides. Enterococcus faecalis and E. faecium isolates had high MICs for aminocyclitols, aminoglycosides, beta-lactams, lincosamides, and sulfonamides. Enterococcus faecalis isolates also showed high MICs for aminocoumarins, while E. faecium isolates had high MICs for trimethoprim/sulfamethoxazole and tetracycline. Based on available veterinary interpretive criteria, 15% and 33% of E. coli isolates were resistant to sulphathiazole and sulphadimethoxine, respectively. Intermediate susceptibility to florfenicol was seen with 17.8% of E. coli isolates. Twenty percent of E. faecalis and 80% of E. faecium isolates were resistant to high-concentration streptomycin. One third of E. faecalis and 70% of E. faecium isolates were intermediately susceptible to erythromycin. Ten percent of E. faecium isolates were resistant to tetracycline and oxytetracycline. A comparison of available MIC suggests that AMR in wild bobwhite is less severe than in domestic poultry. Further investigation is needed to determine the source of AMR in wild bobwhite.

Activity of 2-(quinolin-4-yloxy)acetamides in Mycobacterium tuberculosis clinical isolates and identification of their molecular target by whole-genome sequencing

The 2-(quinolin-4-yloxy)acetamides (QOAs) have been reported to be promising molecules for tuberculosis treatment. Recent studies demonstrated their potent antimycobacterial activity, biological stability and synergism with rifampicin. The identification of the molecular target is an essential step towards the development of a novel drug candidate. Here, we report the target identification of the QOAs. We found that these compounds are active against Mycobacterium tuberculosis clinical isolates resistant to isoniazid, rifampicin, ethambutol, streptomycin and ethionamide. The initial evidence that DNA gyrase might be the target of QOAs, based on high minimum inhibitory concentration (MIC) values against ofloxacin-resistant clinical isolates and structural similarities with fluoroquinolones, was discarded by experiments performed with M. tuberculosis GyrA point mutant, DNA gyrase supercoiling inhibition assay and overexpression of DNA gyrase. We selected spontaneous mutants for our lead compound 21 and observed that these strains were also resistant to all QOA derivatives. The genomes of the spontaneous mutants were sequenced, and the results revealed a single mutation in qcrB gene (T313A), which indicates that the QOAs target the cytochrome bc1 complex. The protein-compound interaction was further investigated by molecular docking. These findings reinforce the relevance of these compounds as promising candidates for the treatment of multidrug-resistant tuberculosis.

Resistance mechanisms against quinolones in Mycoplasma capricolum subsp. capricolum

Quinolones interact with bacterial DNA gyrase and topoisomerase IV, the subunits of which are encoded by gyrA/gyrB and parC/parE, respectively. The aim of this study was to evaluate the relationship between changes in these genes and quinolone susceptibility of Mycoplasma capricolum subsp. capricolum (Mcc). Using in vitro selected resistant mutants and field isolates from goats, predicted amino acid changes in gyrA, gyrB and parC were associated with higher minimum inhibitory concentration values for quinolones. Alterations in parC predicted amino acid sequences were most frequently associated with quinolone resistance in Mcc.

Molecular Identification and Antifungal Susceptibility Patterns of Clinical Dermatophytes Following CLSI and EUCAST Guidelines.

Dermatophytes are associated with superficial infections in humans worldwide. The aim of the present study was to determine the species distribution and susceptibility patterns of clinical dermatophytes. Samples received for routine mycological processing from 124 suspected cases attending a dermatologic clinic in a tertiary care hospital were included in the study. On direct microscopy, 74.1% (92/124) were positive and 53.2% (66/124) grew on culture. The isolates were comprised of Trichophyton interdigitale (56%) followed by Trichophyton tonsurans (25.7%), Trichophyton rubrum (7.5%), Trichophyton violaceum (4.5%), Microsporum gypseum (4.5%), and Trichophyton verrucosum (1.5%). Conventional mycological identification was concordant with ITS sequencing except for T. mentagrophytes. High minimum inhibitory concentration (MIC) values (geometric mean, >1 µg/mL) were observed for T. tonsurans and T. rubrum to terbinafine and griseofulvin. This study highlights the shift in epidemiology from T. rubrum to T. interdigitale. It also raises a concern of high MICs of terbinafine and griseofulvin among our isolates. Surveillance of antifungal susceptibility patterns can provide clinicians with local MIC data that can further aid in guiding better management in relapse cases of dermatomycosis.

Antimicrobial susceptibility of clinical isolates of Actinomyces and related genera reveals an unusual clindamycin resistance among Actinomyces urogenitalis strains.

Patterns of antimicrobial susceptibility in Actinomyces and related genera are very limited in the literature. Data of predominant susceptibility profiles could contribute to the establishment of an accurate empirical treatment. A total of 113 isolates from clinical samples were included in this study. Each isolate was identified using phenotypic methods and MALDI-TOF/MS. When discrepancies were observed, 16S rRNA gene sequencing was performed. The minimum inhibitory concentrations (MICs) of nine antimicrobial agents (penicillin, ceftriaxone, linezolid, tetracycline, clindamycin, erythromycin, ciprofloxacin, levofloxacin and vancomycin) were tested against the species Actinotignum schaalii (n=23), Actinomyces turicensis (n=18), Actinomyces europaeus (n=13), Actinomyces naeslundii/Actinomyces viscosus group (n=12), Actinomyces urogenitalis (n=11), Actinomyces radingae (n=11), Actinomyces neuii (n=9), Actinomyces odontolyticus (n=8), Bifidobacterium scardovii (n=3), Actinomyces graevenitzii (n=2), Alloscardovia omnicolens (n=2) and Varibaculum cambriense (n=1). All of the isolates were susceptible to penicillin, ceftriaxone, vancomycin and linezolid. Almost all of the A. urogenitalis isolates (8/11) were resistant to clindamycin and showed susceptibility to erythromycin, suggesting an L-phenotype, however no determinants of clindamycin resistance (lnu and lsa genes) were detected by PCR. High MIC values to quinolones were observed in 54/113 isolates (47.8%). All of the A. urogenitalis isolates were highly resistant to ciprofloxacin and levofloxacin. These data highlight the importance of ongoing surveillance to provide relevant information for empirical management of infections caused by these organisms.

Investigation of Carbapenem-Resistant AcinetobacterBaumannii Resistance Rate in Clinical Specimens of Newborns at Imam Khomeini Hospital in Tehran

Background: Carbapenem-resistant Acinetobacter Baumannii (CRAB) hospital infection poses a serious threat to the health of the newborns in neonatal intensive care units (NICU). The present study was conducted to evaluate the prevalence and resistance of hospital infections in the NICU ward at Imam Khomeini hospital in Tehran.Materials and Methods: The blaOXA-51 like gene was investigated with polymerase chain reaction (PCR). Then, sensitivity of isolates to different antibiotics was assessed using disc diffusion method and broth micro dilutions to determine the minimum inhibitory concentrations (MICs). Pulsed field gel electrophoresis (PFGE) was used for typing of randomly collected CRAB infection at different wards of this hospital. Results: A total of 10 CRAB infections were isolatedduringthe6-month study period, and it was found that 100% of them were positive forblaOXA-51-like gene in PCR assay. All isolates were resistant to all tested antibiotics, except colistin, polymyxin B, and tigecycline. CRAB isolates had a high MIC values for imipenem, cefotaxim, and amikacin, showing multidrug resistant (MDR) phenotype. According to PFGE analysis,3palsotypes including clone A (7%), clone B (2%), and clone D (1%) were seen in the 10 CRAB isolates. Clone A was a dominant clone and spread in different wards of the hospital, especially in other ICUs and the emergency ward. Moreover, the similarity between the palsotypes showed the ability of transferring CRAB infection from different wards of the hospital to the NICU.Conclusions: Based on the results of this study, CRAB infection, with a high resistance rate, has the ability to enter into important wards such as NICU, and thus it is highly important to control the presence of these isolates in different parts of the hospital.

In vitro activity of kombucha tea ethyl acetate fraction against Malassezia species isolated from seborrhoeic dermatitis.

Background and Purpose:Seborrheic dermatitis is a chronic and recurrent superficial dermatitis in which Malassezia species play an important role. There are different Malassezia species, which have been recently reported to be resistant to common antifungals. Natural sources can be useful alternatives to reduce the emergence of this resistance. Kombucha tea is believed to have potential antimicrobial properties. Regarding this, the present study aimed to investigate the antifungal activity of Kombucha tea ethyl acetate fraction (KEAF) against Malassezia species obtained from the patients with seborrheic dermatitis. Materials and Methods:A total of 23 clinical isolates were identified by direct microscopic examination and Tween assimilation, and then confirmed by DNA sequencing of ITS regions for Malassezia species. Kombucha tea was fractionated using ethyl acetate (1:2 v/v). The minimum inhibitory concentration (MIC) microdilution assay was used to evaluate the anti-Malssezia activity of KEAF at three concentrations of 10, 40, and 80 mg/mL. Results:The results of the DNA sequence analysis indicated that M. furfur (39.13%) was the predominant species, followed by M. globosa (30.43%), M. sloofie (13.04%), M. sympodialis (13.04%), and M. restricta (4.34%), respectively. Furthermore, KEAF showed inhibitory activity against Malassezia species. Accordingly, KEAF had the lowest and highest MIC value against M. sloofie and M. restricta, respectively. Moreover, the inhibitory effect of the extract was equivalent to that of ketoconazole at 4.8 µg/mL. Conclusion:The findings of the current study highlighted the antifungal properties of KEAF. Therefore, this extract can be promoted as complementary medicine for the treatment of the infections caused by Malassezia.