High Incidence Of Resistance Research Articles

A growing threat: Investigating the high incidence of benzimidazole fungicides resistance in Iranian Botrytis cinerea isolates.

Effective management of fungicide application programs requires monitoring the profile of resistant populations of Botrytis cinerea, given its high-risk nature. This research aimed to examine the sensitivity of 200 B. cinerea isolates collected from different plant species and regions across Iran towards thiophanate-methyl and carbendazim fungicides. To distinguish between susceptible and resistant isolates, the discriminatory dose assay was employed, followed by the selection of representative isolates from each group for EC50 analysis. To identify potential modifications in codon 198 of the β-tubulin gene in B. cinerea resistant isolates, the researchers employed the PCR-RFLP diagnostic method. More than two-thirds of the isolates exhibited a varying degree of resistance to MBC fungicides, even in farms where the application of these fungicides had not taken place in recent years. After treatment with the BsaI enzyme, the PCR product of sensitive isolates displayed two bands measuring 98 and 371 bp, while only one band of 469 bp was identified in resistant isolates. The study also evaluated whether resistance to fungicides could affect the pathogenicity and mycelial growth of the isolates. The findings showed no significant difference between the resistant and sensitive groups in terms of these factors, indicating that resistance does not come at a cost to the pathogen's fitness. Considering the high incidence of resistance and the absence of negative consequences on fitness, it is recommended to exercise caution in the employment of benzimidazole fungicides as part of B. cinerea management strategies.

Towards Precision Oncology: The Role of Smoothened and Its Variants in Cancer.

The G protein-coupled receptor Smoothened (Smo) is a central signal transducer of the Hedgehog (Hh) pathway which has been linked to diverse forms of tumours. Stimulated by advancements in structural and functional characterisation, the Smo receptor has been recognised as an important therapeutic target in Hh-driven cancers, and several Smo inhibitors have now been approved for cancer therapy. This receptor is also known to be an oncoprotein itself and its gain-of-function variants have been associated with skin, brain, and liver cancers. According to the COSMIC database, oncogenic mutations of Smo have been identified in various other tumours, although their oncogenic effect remains unknown in these tissues. Drug resistance is a common challenge in cancer therapies targeting Smo, and data analysis shows that healthy individuals also harbour resistance mutations. Based on the importance of Smo in cancer progression and the high incidence of resistance towards Smo inhibitors, this review suggests that detection of Smo variants through tumour profiling could lead to increased precision and improved outcomes of anti-cancer treatments.

Transcriptional Response of Candida auris to the Mrr1 Inducers Methylglyoxal and Benomyl.

ABSTRACTCandida auris is an urgent threat to human health due to its rapid spread in health care settings and its repeated development of multidrug resistance. Diseases that increase risk for C. auris infection, such as diabetes, kidney failure, or immunocompromising conditions, are associated with elevated levels of methylglyoxal (MG), a reactive dicarbonyl compound derived from several metabolic processes. In other Candida species, expression of MG reductase enzymes that catabolize and detoxify MG are controlled by Mrr1, a multidrug resistance-associated transcription factor, and MG induces Mrr1 activity. Here, we used transcriptomics and genetic assays to determine that C. auris MRR1a contributes to MG resistance, and that the main Mrr1a targets are an MG reductase and MDR1, which encodes a drug efflux protein. The C. auris Mrr1a regulon is smaller than Mrr1 regulons described in other species. In addition to MG, benomyl (BEN), a known Mrr1 stimulus, induces C. auris Mrr1 activity, and characterization of the MRR1a-dependent and -independent transcriptional responses revealed substantial overlap in genes that were differentially expressed in response to each compound. Additionally, we found that an MRR1 allele specific to one C. auris phylogenetic clade, clade III, encodes a hyperactive Mrr1 variant, and this activity correlated with higher MG resistance. C. auris MRR1a alleles were functional in Candida lusitaniae and were inducible by BEN, but not by MG, suggesting that the two Mrr1 inducers act via different mechanisms. Together, the data presented in this work contribute to the understanding of Mrr1 activity and MG resistance in C. auris.IMPORTANCE Candida auris is a fungal pathogen that has spread since its identification in 2009 and is of concern due to its high incidence of resistance against multiple classes of antifungal drugs. In other Candida species, the transcription factor Mrr1 plays a major role in resistance against azole antifungals and other toxins. More recently, Mrr1 has been recognized to contribute to resistance to methylglyoxal (MG), a toxic metabolic product that is often elevated in different disease states. MG can activate Mrr1 and its induction of Mdr1 which can protect against diverse challenges. The significance of this work lies in showing that MG is also an inducer of Mrr1 in C. auris, and that one of the major pathogenic C. auris lineages has an activating Mrr1 mutation that confers protection against MG.

Virulence and Antimicrobial Resistance Pattern of Aeromonas spp. Colonizing European Pond Turtles Emys orbicularis and Their Natural Environment. First Study from Poland.

Simple SummaryAeromonas species are Gram-negative facultative anaerobic bacteria with a wide distribution in nature. The genus comprises bacteria which can cause different types of diseases in many warm- and cold-blooded animals. Moreover, exposure to these bacteria can cause gastroenteritis or localized skin infections in humans. In the current study, Aeromonas species were identified in samples from water sources and European pond turtles (Emys orbicularis) from Eastern Poland. Our results revealed a high prevalence of Aeromonas isolates (43.2%) in the turtles and 66.7% in the water samples. All isolates were resistant to ampicillin, 62% to sulfamethoxazole, 40.5% to erythromycin, and 40.5% to colistin. Eight strains were intermediately resistant to meropenem. Additionally, most Aeromonas isolates (from 90.5% to 45.2%) were found to possess the following virulence genes: fla, aer, hlyA, act, ela, alt, and ast. This report indicated that European pond turtles were colonized by Aeromonas spp. While acting as reservoirs for these pathogens, they may play an important role in the etiology of Aeromonas-associated animal infections. Moreover, the undesirable properties of water quality caused by the presence of drug-resistant aeromonads could exert a negative impact on human health.The aim of the study was to isolate and identify species belonging to the Aeromonas genus and evaluate the antimicrobial resistance and virulence patterns of isolates colonizing European pond turtles (Emys orbicularis) from natural environment of Eastern Poland. In total, 74 turtles and 15 samples of water from their natural environment were examined. More than 40 strains were isolated and identified: A. bestiarum (n = 1), A. hydrophila (n = 13), A. allosaccharophila (n = 2), A. salmonicida (n = 3), and A. veronii (n = 23). The highest incidence of resistance was noted for ampicillin (100%) and sulfamethoxazole (62.0%), followed by erythromycin and colistin (both 40.5%). Moreover, eight strains were intermediately resistant to meropenem (19%). Most Aeromonas isolates were found to possess more than one virulence gene among fla, aer, hlyA, act, ela, alt, and ast. We showed that the population of free-living European pond turtles was highly colonized by Aeromonas spp. Such strains may be an infectious agent not only for the population of turtles but also for other species of animals inhabiting their natural environment. Moreover, the undesirable properties of water quality caused by the presence of drug-resistant aeromonads could have a negative impact on human health.

Enhanced Efficacy of Some Antibiotics in Presence of Silver Nanoparticles Against Multidrug Resistant Pseudomonas aeruginosa Recovered From Burn Wound Infections.

Burn wound infections with multidrug-resistant (MDR) bacteria are shown in many countries as severe widespread health threats. Consequently, attention has been devoted to new nanoparticle-based materials in the field of antimicrobial chemotherapy for burn wound infections. This study aimed to evaluate both in vitro and in vivo efficacies of nanoparticle–antibiotic combinations as new classes of materials subjected against MDR Pseudomonas aeruginosa. Out of 40 Gram-negative isolates, 23 P. aeruginosa were recovered from patients with burn wound infections attending different hospitals in Tanta, Egypt. The susceptibility test revealed that 95.7% of P. aeruginosa isolates were MDR with a high incidence of resistance against carbenicillin. Antibacterial activities of silver nanoparticles (Ag-NPs) against the isolates examined showed various inhibition zone diameters ranging from 11 to 17 mm. Strong synergistic efficacy of neomycin was reported in combination with Ag-NPs against MDR P. aeruginosa P8 and P14 isolates. The in vivo effectiveness of various pharmaceutical formulations prepared from a combination of neomycin antibiotic with Ag-NPs in the treatment of induced bacterially infected mice burns showed that maximum healing activity along with faster wound contraction reported with the combination of neomycin-Ag-NPs in the spray formulation. Generally, data indicated that incorporating Ag-NPs in combination with certain antibiotics may be a new, promising application for wound treatments, especially burns infected with MDR P. aeruginosa.

IMPACT OF TEA TREE OIL ON BIOFILM FORMATION AND SWARMING MOTILITY BY MDR PROTEUS MIRABILIS

Emergence of multi-drug resistant isolates of P. mirabilis and development of new resistant microbial phenotypes are growing and the outlook for the use of antimicrobial drugs in the future is still uncertain. Therefore, there is an increased demand for developing alternative strategies to conventional antibiotic therapy and to continue studies to develop new drugs, either synthetic or natural. In this study, 25 isolates of P. mirabilis were isolated from different clinical samples collected from different departments of Tanta University hospitals. All isolates were resistant to amoxicillin, azithromycin and tetracycline. A high incidence of resistance was also recorded for cefprozil (96%) and cefotaxime (80%). P. mirabilis isolates were moderately resistant to imipenem (64%), lomefloxacin (64%), ampicillin (60%), cefepime (60%) and ciprofloxacin (52%). However, the lowest incidence of resistance was recorded for amikacin (8%). All isolates showed MAR indices >0.2 and exhibited MDR profile. The antimicrobial activity of tea tree oil was evaluated using agar dilution method recording MIC50 value of 12.8 mg/ml. The effect of tea tree oil on the strong biofilm producer isolates with relatively wide swarming zone diameters was evaluated. Results obtained showed that tea tree oil (1/4 and 1/2 MIC) presented significant and dose-dependent inhibition in the biofilm production by the tested isolates of P. mirabilis by ≥50%. In addition, tea tree oil inhibited the swarming motility of P. mirabilis isolates in a dose-dependent manner. Therefore, tea tree oil could act as a potential source of alternative antimicrobials or as antipathogenic compound against MDR P.mirabilis.

Wound Healing Potential of Polyherbal Formulation in Rats

Chronic wound infections are significant medical burden as the patients have to go through severe discomfort and distress. Invasion of various pathogenic microorganisms at the injured site further leads to damage of tissue which may results in resection of the organ. Appropriate wound healing is necessary to regain the functional and anatomical status of the damaged tissue that got disturbed due to wound. Conventional antibiotics used for the treatment of infections are associated with various drawbacks such as high cost and high incidence of resistance. Moreover, the dressing used for wounds are also unable to provide adequate moisture to the injured tissue. All these factors emphasise on the development of new advanced technologies for wound care. Polyherbal formulations, which comprise of various medicinal plant extracts, exhibit antioxidant and anti-inflammatory properties and can be much better alternative to commercial antibiotics for treatment of wound infections. In the present study, wound healing potential of “Septaheal” (a Polyherbal formulation) was evaluated in Wistar albino rats using incision, excision and burn wound models. The formulation exhibited wound healing property due to its angiogenic and mitogenic potential.

Antibiotic Sensitivity and Antilysozyme Activity of <i>Staphylococcus aureus</i> Strains Isolated from the Blood of Patients with Sepsis

Effective antibiotic therapy requires reliable data on the dynamics of sensitivity changes in each region. The aim of the study was to determine the sensitivity to antibiotics and antilysozyme activity of Staphylococcus aureus strains isolated from the blood of patients with sepsis over the period from 2017 to 2019. An increase in the resistance of Staphylococcus aureus to ceftriaxone, cefixime vancomycin, azithromycin, and levofloxacin was noted. Given the high incidence of resistance, the use of these drugs should be limited. Ceftazidime, tigecycline, daptomycin, and linezolid can be considered drugs of choice in empiric therapy of septic diseases of staphylococcal etiology. Most of the isolated strains exhibited antilysozyme activity (ALA). Most commonly the cultures had medium to high ALA scores.

The Wide Range of Antibiotic Resistance and Variability of Genotypic Profiles in Escherichia coli from Domestic Animals in Eastern Sicily.

The emergence of multidrug resistance among Enterobacteriaceae in livestock poses a serious public health threat. Escherichia coli, a usual host of intestinal microbiota, is recognized also as etiological agent of numerous infections widespread in both humans and animals. The colibacillosis is one of the most reported zoonoses worldwide, typically treated with antibiotics in the primary stages. This strategy has promoted the onset of antibiotic-resistant serotypes of E. coli, reducing the effectiveness of therapeutic treatments and contributing to antibiotic resistance spread. The current study focused on biodiversity, pathogenicity, and antibiotic resistance profile of 104 E. coli strains isolated from domestic animals in Eastern Sicily. The strains were isolated from sick animals and carcasses of six different animal species and screened for resistance against 16 antibiotic molecules, as recommended by WHO and OIE. The antibiotic resistance patterns highlighted that all strains were multi-resistant, showing resistance to at least three antibiotic classes. The highest incidence of resistance was observed against amoxicillin (100%), tylosin (97%), sulfamethoxazole (98%), and erythromycin (92%), while the lowest for colistin (8%). The pathotype characterization identified two EPEC strains and the study of genetic linkage (PFGE) showed a wide variety of profiles. The current study emphasized the wide range of multidrug resistance and genotyping profiles in E. coli isolated in Easter Sicily.

Successful treatment of resistant onychomycosis with voriconazole in a liver transplant patient.

Onychomycosis is a common chronic fungal infection of the nails caused by dermatophytes, yeasts, and non-dermatophyte filamentous fungi. A relatively high incidence of resistance and treatment failure of onychomycosis to traditional systemic antifungal agents such as terbinafine and itraconazole has been reported. Voriconazole is a novel broad spectrum systemic antifungal that has shown high efficacy against various types of dermatophytes including Trichophyton and Microsporum species in many in vitro and, recently, in two in vivo studies of resistant dermatophytosis. Herein, we report the successful treatment of a resistant case of finger nail onychomycosis by oral voriconazole in a liver transplant patient who failed to respond to traditional systemic antifungals.

Frequency and Antimicrobial Resistance Pattern among Bacterial Clinical Isolates Recovered from Different Specimens in Egypt

Antimicrobial resistance (AMR) is a global public health threat resulting in high mortality rates. Current study aimed to identify the most prevalent pathogens among variable infection sites and their AMR pattern. Data concerning cultures and antibiotic susceptibilities were retrieved from Microbiology Department’s records and statistically analyzed. Out of 554 bacterial isolates, Gram negative isolates (68.4%) were predominant. Urine specimens showed the highest incidence of recovery of total isolates (41.5%, n=230) followed by blood (23.1%, n=128), while sputum specimens exhibited the least frequency (17%, n=94). <i>E. coli</i> (30.7%, n=170), <i>S. aureus</i> (21.1%, n=117) and Klebsiella spp (20.9%, n=116) were the most frequently isolated pathogens. Recovery of isolates was significantly more frequent among males (P<0.05) except in case of urine specimens. Highest incidence of resistance in both Gram positive and Gram negative isolates was recorded in case of cephalosporins and penicillin/β-lactamase. Gram positive isolates exhibited the least resistance to linezolid (10.8%) and vancomycin (9.5%) whereas colistin was the most effective against Gram negative isolates as it recorded 16.4% resistance. Higher frequency of multiple drug resistance (MDR) was also observed in Gram negative isolates compared to Gram positive ones. Resistance to uropathogens and MDR were significantly more frequent in males. Although <i>E. coli</i> was the most prevalent uropathogen but it showed the least incidence of MDR however Pseudomonas spp exhibited the highest MDR rate. The high incidence of resistance in the current study is alarming and highlights the necessity of routinely monitoring the local prevalence of resistance for selecting the best antimicrobial treatment and as a guide for empirical therapy.

In vitro susceptibility of dermatophytes to oral antifungal drugs and amphotericin B in Uttar Pradesh, India.

Dermatophytosis is a major public health problem in our country. Although resistance to conventional oral and topical antifungal agents is being increasingly encountered, the sensitivity pattern of dermatophytes has not been systematically analysed. We aimed to determine the sensitivity pattern of dermatophyte isolates to amphotericin B and six oral antifungal drugs. Patients with dermatophytosis attending the outpatient department of dermatology were enrolled in the study. Samples were collected for mycological examination and in vitro antifungal sensitivity testing was done by broth microdilution as per the Clinical and Laboratory Standard Institute M38-A standards. A total of 804 patients were enrolled. Specimens from 185 patients (23%) were both KOH and culture positive, and 44 of these isolates (41 Trichophyton mentagrophytes and 3 Trichophyton rubrum) were subjected to sensitivity testing. Minimum inhibitory concentrations (MIC) of itraconazole, ketoconazole, voriconazole and amphotericin B were comparable. The median MIC to fluconazole was higher than the other tested drugs. Dermatophytes were most susceptible to ketoconazole and voriconazole, followed by itraconazole, amphotericin B, fluconazole and griseofulvin. A high incidence of resistance was found to terbinafine and the difference was statistically significant in comparison to fluconazole, itraconazole, voriconazole, ketoconazole (P = 0.001) and griseofulvin (P = 0.003). The strains were more sensitive to amphotericin B as compared to griseofulvin (P = 0.02) and terbinafine (P < 0.001). This was a hospital-based study and may not reflect the true pattern in the community. Only a few of the isolates were selected for study. The clinical response of patients, whose isolates were studied for in vitro sensitivity of the antifungals, was not studied. The sensitivity pattern of dermatophytes to various antifungals including amphotericin B, ketoconazole, voriconazole and itraconazole were determined. The studied isolates were least susceptible to terbinafine.

Enterococcus spp. in Ragusano PDO and Pecorino Siciliano cheese types: A snapshot of their antibiotic resistance distribution

In the present study, 110 enterococci were isolated from two Sicilian cheese types, Ragusano PDO and Pecorino Siciliano. Isolates, firstly identified by MALDI-TOF/MS and a multiplex PCR assay, were tested for susceptibility to the most relevant clinical antibiotics. Clonal relationships among isolates were evaluated by pulsed-field-gel electrophoresis (PFGE) analysis and the presence of vanA and vanB genes, in vancomycin resistant enterococci (VRE), was investigated. Overall, E. faecalis, E. durans (35% for each species) and E. faecium (28%) were the major identified species. Different occurrence between cheese types was revealed. Most isolates from Ragusano PDO cheese were identified as E. durans (46%) and/or E. faecalis (43%), while E. faecium (605) was mainly detected in Pecorino Siciliano cheese. High incidence of resistance (97% of total strains) was detected for rifampicin, erythromycin and ampicillin. Moreover, 83 isolates (75%) exhibited multidrug-resistant phenotypes and the one VRE (vanB) isolate was identified as E. durans. PFGE analysis clustered isolates into 22 genotypes and the presence of the same PFGE types, for both E. durans and E. faecalis, in the two cheese types, suggest the link between enterococci and geographical area of production. Results of present study raise concerns about possible role of dairy enterococci as reservoirs of antibiotic resistance.

Relative abundance and fungicide resistance patterns of Botrytis cinerea and B. pseudocinerea on apple in Northern Germany

In the Lower Elbe region of Northern Germany, low levels of fungicide resistance were recorded among Botrytis isolates obtained from blossom-end rot lesions on growing apple fruit. In contrast, isolates collected from apples affected by grey mould in storage possessed a high incidence of resistance to trifloxystrobin and boscalid (> 30% of strains) as well as elevated shares of resistance to thiophanate-methyl, iprodione, fenhexamid, fludioxonil and cyprodinil. Fluopyram resistance was rare. On the basis of fungicide resistance responses as well as BC1G_07159 gene features, B. pseudocinerea was shown to be the most frequent blossom-end rot pathogen, whereas B. cinerea was dominant as a storage rot. This pattern applied to orchards under organic as well as integrated pest management.

Abstract B123: A mesenchymal subset of cancers with elevated ZEB1 expression is sensitive to low doses of silver nanoparticles

Abstract The epithelial-to-mesenchymal transition (EMT) is an evolutionarily conserved process that is required for normal development. However, EMT is often dysregulated and hijacked by cancers during tumor progression. Cancer cells that have undergone EMT and acquired a mesenchymal phenotype harbor several distinct traits, including increased tumor initiating properties, augmented motility, increased metastatic properties, and a higher incidence of resistance to therapy. Therefore, treatment regimens specific to mesenchymal cancer cells would be advantageous. In this study, we discovered that a mesenchymal subpopulation of breast, ovarian, lung, colorectal, and prostate cancer cell lines with high expression of the transcription factor ZEB1 (zinc finger E-box binding homeobox 1) and low expression of epithelial genes repressed by ZEB1 including ESRP1 (epithelial splicing regulatory protein 1) and CDH1 (E-cadherin) are an order of magnitude (&amp;gt;10-fold) more sensitive to exposure to silver nanoparticles (AgNPs) than cells expressing only low levels of ZEB1. This finding is significant because: (i) This is the first time a biomarker has been identified that is predictive of a positive response to any form of engineered nanomaterial; (ii) ZEB1 expression is a marker of poor clinical prognosis, and therefore identification of improved therapeutics for this poor outcome patient population is desirable; (iii) this work establishes that there is a shared and exploitable vulnerability across multiple cancer types that is independent of tissue origin and identifiable based upon mRNA or protein quantification of ZEB1. We establish that the ZEB1high selective cytotoxic properties of biocompatible AgNPs are not achieved using ionic silver, and therefore is one of the first examples of a “new to nano” cytotoxic property. Mechanistically, we find that AgNPs are rapidly ionized in ZEB1high cells, leading to endoplasmic reticulum stress, DNA damage, and apoptotic cell death. Furthermore, we show that AgNPs do not disrupt the normal architecture of breast acini in 3D cell culture, nor do they cause DNA damage. In contrast, the same doses of AgNPs cause extensive DNA damage and apoptosis in ZEB1high breast tumor nodules produced in 3D culture. Induction of EMT using TGF-β increases sensitivity to AgNPs and, conversely, knockdown of ZEB1 desensitizes cells to AgNP therapy. Finally, we demonstrate that systemic administration of AgNPs is safe and effective for treatment of ZEB1high breast cancer orthotopic xenografts in mice. In conclusion, our work provides evidence that a therapeutic window exists for the safe use of AgNPs as a precision medicine for patients with ZEB1-expressing tumors regardless of tissue origin. Citation Format: Cale D. Fahrenholtz, Jessica Swanner, James Sears, Katherine Cook, Pierre-Alexandre Vidi, Ravi Singh. A mesenchymal subset of cancers with elevated ZEB1 expression is sensitive to low doses of silver nanoparticles [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B123.

An abnormality in glucocorticoid receptor expression differentiates steroid responders from nonresponders in keloid disease.

SummaryBackgroundGlucocorticoids (GCs) are first‐line treatment for keloid disease (KD) but are limited by high incidence of resistance, recurrence and undesirable side‐effects. Identifying patient responsiveness early could guide therapy.MethodsNineteen patients with KD were recruited at week 0 (before treatment) and received intralesional steroids. At weeks 0, 2 and 4, noninvasive imaging and biopsies were performed. Responsiveness was determined by clinical response and a significant reduction in vascular perfusion following steroid treatment, using full‐field laser perfusion imaging (FLPI). Responsiveness was also evaluated using (i) spectrophotometric intracutaneous analysis to quantify changes in collagen and melanin and (ii) histology to identify changes in epidermal thickness and glycosaminoglycan (GAG) expression. Biopsies were used to quantify changes in glucocorticoid receptor (GR) expression using quantitative reverse transcriptase polymerase chain reaction, immunoblotting and immunohistochemistry.ResultsAt week 2, the FLPI was used to separate patients into steroid responsive (n = 12) and nonresponsive groups (n = 7). All patients demonstrated a significant decrease in GAG at week 2 (P < 0·05). At week 4, responsive patients exhibited significant reduction in melanin, GAG, epidermal thickness (all P < 0·05) and a continued reduction in perfusion (P < 0·001) compared with nonresponders. Steroid‐responsive patients had increased GR expression at baseline and showed autoregulation of GR compared with nonresponders, who showed no change in GR transcription or protein.ConclusionsThis is the first demonstration that keloid response to steroids can be measured objectively using noninvasive imaging. FLPI is a potentially reliable tool to stratify KD responsiveness. Altered GR expression may be the mechanism gating therapeutic response.

Isolation and identification of Acinetobacter species with special reference to antibiotic resistance.

Background:Acinetobacter is clinically important pathogen with widespread resistance to various antibiotics. We assessed the incidence of Acinetobacter infection at a tertiary care hospital, analyze their resistance pattern and identify the production of extended spectrum β-lactamases (ESBLs) and metallo β-lactamases (MBLs).Materials and Methods:The study was conducted in tertiary care hospital, India over a period of 2 years. Acinetobacter species were isolated from various clinical samples received in Department of Microbiology. After identification, Acinetobacter isolates were speciated and antibiotic susceptibility was determined by the standard disc diffusion method. ESBL and MBL production was detected by the double disc synergy test and combined disc diffusion test respectively.Results:Of 3298 infected samples, 111 (3.36%) were found to be Acinetobacter. The most predominant species was Acinetobacter calcoaceticus-A. baumannii (Acb) complex (72%). High incidence of resistance was recorded for piperacillin (55%), followed by ceftriaxone (46%) and ceftazidime (46%). Isolation rate and antibiotic resistance was higher in the Intensive Care Units (ICUs) of the hospital. ESBL and MBL production was detected in 31.5% and 14.4% of the isolates respectively.Discussion and Conclusion:A high level of antibiotic resistance was observed in our study and maximum isolation rate of Acinetobacter was in the ICUs. Acb complex was the most predominant and most resistant species. The analysis of susceptibility pattern will be useful in understanding the epidemiology of this organism in our hospital setup, which will help in treating individual cases and controlling the spread of resistant isolates to other individuals.

Abstract 3212: Ganoderma lucidum (Reishi) chemosensitizes EGFR-overexpressing inflammatory breast cancer cells to erlotinib

Abstract Inflammatory Breast Cancer (IBC) is an aggressive cancer with a unique ability of forming tumor spheroids, which invade the dermal lymphatics causing the inflammatory phenotype. IBC cell lines and human tissues, overexpress Epidermal Growth Factor Receptor (EGFR), which has been associated with increasing IBC tumor growth rate, invasion and metastasis. Among the current therapeutic strategies for EGFR inhibition are the small molecule Tyrosine Kinase Inhibitors (TKIs). The high incidence of resistance to such therapies has greatly diminished their overall effectiveness, thus it seems feasible to identify agents that may be combined with these TKIs to provide a sustained response for IBC patients. For this reason, the purpose of this study is to investigate Reishi's therapeutic potential in IBC, focusing on the regulation of the EGFR signaling cascade and its contribution to the IBC cellular response when treated with the EGFR TKI, erlotinib. Our hypothesis is that Reishi sensitizes IBC cells to erlotinib therapy. EGFR-overexpressing SUM-149 IBC cells were treated with several concentrations of erlotinib, 0.025mg/mL Reishi, or both treatments simultaneously for 72h. Our results showed a synergistic effect when erlotinib and Reishi are used simultaneously after 72 hours of treatment. In order to study the molecular mechanism for the improved effects of the combination treatment we successfully developed an IBC erlotinib resistant cell line from the parental SUM-149 cells. Our data revealed that Reishi increases erlotinib sensitivity by inactivating AKT and extracellular signal-regulated kinase (ERK) signaling pathways. Taken together, our results provide evidence that Reishi chemosensitizes IBC cells to erlotinib therapy, highlighting its anti-IBC-therapeutic potential. This project was sponsored by NIH/NCI #1F31 CA174307 to ISA, Title V PPOHA US Department of Education #P031M105050 to UCC, NIH/RCMI #G12 MD007583 to UCC, NIH/INBRE #5P20 GM103475 to UPR/UCC and a research donation from the Commonwealth of Puerto Rico to UCC's University Center of Integral and Complementary Medicine (CUMIC)/MMM. Citation Format: Ivette Suárez-Arroyo, Michael Moraskie, Luis A. Cubano, Michelle M. Martínez-Montemayor. Ganoderma lucidum (Reishi) chemosensitizes EGFR-overexpressing inflammatory breast cancer cells to erlotinib. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3212. doi:10.1158/1538-7445.AM2014-3212

Antimicrobial Susceptibility and Characterization of Outer Membrane Proteins of Aeromonas hydrophila Isolated in China

Aeromonas hydrophila isolates from clinical cases (n=43) were tested against 8 antimicrobial agents and typed by outer membrane protein (OMP) pattern by using sodium dodecyl sulfate gel electrophoresis. All isolates were resistant to ampicillin (MICs, ≥16 μg mL−1) and sulfamonomethoxine (MICs, ≥64 μg mL−1), but susceptible to norfloxacin (MICs, ≤0.5 μg mL−1). There was a high incidence of resistance to erythromycin (90.70%) and tylosin (93.02%), while a low incidences of resistance to ciprofloxacin (2.33%), enrofloxacin (2.33%) and florfenicol (4.65%). Six different outer membrane protein patterns were found among 34 isolates by analyzing proteins in the range of 22 to 50 kDa, other than 9 isolates with their respective profiles. The strains with the similar OMP profiles had similar resistances. Compared with the other strains from the same OMP patterns, NB-1, A.Pun and MR-1 had lacked the proteins in the range of 30 to 45 kDa and their resistance to florfenicol substantially increased. It is speculated that the outer membrane protein changes might correlate with decreased susceptibility to florfenicol in the three strains. Some strains which showed completely identical OMP types had a little difference in their resistance to fluoroquinolones, indicating that there might be other factors that were involved in the antimicrobial resistance of A. hydrophila.

Photosensitive Pt(IV)–azide prodrug-loaded nanoparticles exhibit controlled drug release and enhanced efficacy in vivo

Cisplatin has long been the first line of treatment for a variety of solid tumors. However, poor pharmacokinetics and high incidences of resistance in the clinic have motivated the production of numerous alternative Pt-based anticancer species. Recently, photosensitive Pt(IV) complexes have garnered much interest because they offer a method of selective induction of active Pt(II) at the tumor site by UVA irradiation. Here, we report the first synthesis, in vitro and in vivo characterization of a novel series of photosensitive Pt(IV)–azide prodrugs and micellar nanoparticle formulations thereof. Upon mild UVA irradiation, both free Pt(IV) complexes and micellar nanoparticles rapidly released biologically active Pt(II), capable of binding to 5′-GMP, while remaining extremely stable in the dark. In vitro, uptake of photosensitive Pt(IV) prodrugs by ovarian cancer SKOV-3 cells was greatly enhanced with the micellar nanoparticles compared to their free prodrug analogs, as well as cisplatin and oxaliplatin. Increased cytotoxicity was observed upon UVA treatment, with up to a 13-fold enhancement over oxaliplatin for the micellar nanoparticles. In vivo bioavailability of micellar nanoparticles was enhanced ~10 fold over free Pt(IV) prodrugs. Importantly, micellar nanoparticles demonstrated significantly improved efficacy against H22 murine hepatocarcinoma, showing decreased systemic toxicity and increased tumor growth inhibition relative to small molecule drugs. These findings establish that photosensitive Pt(IV) complexes, specifically when formulated into micellar nanoparticles, have the potential to offer a robust platform for the controlled delivery and selective activation of Pt-based anticancer therapeutics.