Multi Drug Research Articles

Changing epidemiology and antimicrobial resistance in Vibrio cholerae: AMR surveillance findings (2006\u20132016) from Nepal

BackgroundIn Nepal, cases of Cholera occur annually either as sporadic or as outbreaks claiming the lives of many in rural areas. The present study is a laboratory based surveillance which aims to analyze the changing epidemiology and antimicrobial susceptibility trend of V. cholerae strains isolated or referred to National Public Health Laboratory (NPHL) over a period of 11 years (2006–2016).MethodsSpecimens of fresh stool /rectal swab either received at sentinel sites or NPHL were processed following standard microbiological techniques. Suspected colonies on selective medium were identified using routine biochemical tests and confirmed by serotyping. Antimicrobial susceptibility testing was performed following Kirby Baeur disc diffusion method.ResultsOf the 836 confirmed isolates, 87% (728/836) were V.cholerae O1 Ogawa,12% (103/836) were V.cholerae O1 Inaba and only 6 isolates were V.cholerae O1 Hikojima. In 2006 all the Vibrio isolates were of Inaba serotype, followed by all 3 serotypes during 2007.During 2008–2014 only Ogawa serotype was isolated while few cases of Inaba again surfaced in 2015. Resistance to ampicillin decreased from 93% in 2006 to 18% by 2010 and again raised to 100% by 2016.Cotrimoxazole resistance remained at constant range (77–100%).Nalidixic acid resistance was 100% since 2006.Ciprofloxacin and tetracycline resistance emerged in 2007, reached a peak during 2010–2012 and declined to 0 by 2016.Susceptibility to Furazolidone has re-emerged.63.6% of the isolates were Multi drug resistant.ConclusionWith changing epidemiology and antibiogram of V.cholerae in Nepal, the present study reflects the importance of continuous monitoring, which could be used by policy makers and health professionals for better management of outbreaks. Decline in tetracycline and ciprofloxacin resistance along with emerging sensitivity to furazolidone shows that these drugs could make an effective comeback in future.

Multidrug resistance in pathogenic Escherichia coli; a public health concern

Gram-negative bacteria mostly from Enterobacteriaceae family are multidrug resistance and contributing to the antibiotic resistance problems worldwide. Enterobacteriaceae resistance against antibiotics especially β-lactam type is progressively controlled by the organization of constantly expressed genes that code effective drug modifying enzymes. Strong and excessive selection pressure has deceptively been complemented by a transfer from “natural” resistance, such as membrane impermeability, and drug efflux, to the modern pattern of mobile gene pools that mostly decide the epidemiology of modern antibiotic resistance. Escherichia coli is recognized as a pathogen of fecal contamination, its presence in food shows the expected occurrence of other enteric pathogens. The current review focuses on drug-resistant E. coli that are harder to treat with common antibiotics, different ways of multi drug resistance in E. coli and the possible alternative therapeutic procedures for prevention and treatment of these bacteria. Keywords: Antimicrobials; Community health; Nosocomial infections; Pathogenesis; Superbugs http://dx.doi.org/10.19045/bspab.2019.80155

What sustains the multidrug resistance phenotype beyond ABC efflux transporters? Looking beyond the tip of the iceberg.

Identification of multidrug (MDR) efflux transporters that belong to the ATP-Binding Cassette (ABC) superfamily, represented an important breakthrough for understanding cancer multidrug resistance (MDR) and its possible overcoming. However, recent data indicate that drug resistant cells have a complex intracellular physiology that involves constant changes in energetic and oxidative-reductive metabolic pathways, as well as in the molecular circuitries connecting mitochondria, endoplasmic reticulum (ER) and lysosomes. The aim of this review is to discuss the key molecular mechanisms of cellular reprogramming that induce and maintain MDR, beyond the presence of MDR efflux transporters. We specifically highlight how cancer cells characterized by high metabolic plasticity - i.e. cells able to shift the energy metabolism between glycolysis and oxidative phosphorylation, to survive both the normoxic and hypoxic conditions, to modify the cytosolic and mitochondrial oxidative-reductive metabolism, are more prone to adapt to exogenous stressors such as anti-cancer drugs and acquire a MDR phenotype. Similarly, we discuss how changes in mitochondria dynamics and mitophagy rates, changes in proteome stability ensuring non-oncogenic proteostatic mechanisms, changes in ubiquitin/proteasome- and autophagy/lysosome-related pathways, promote the cellular survival under stress conditions, along with the acquisition or maintenance of MDR. After dissecting the complex intracellular crosstalk that takes place during the development of MDR, we suggest that mapping the specific adaptation pathways underlying cell survival in response to stress and targeting these pathways with potent pharmacologic agents may be a new approach to enhance therapeutic efficacy against MDR tumors.

Abstract 1783: A combination therapy of atypical protein kinase inhibitor and phosphatidylinositol-3- kinase inhibitor reduces multidrug resistance in renal cell carcinoma (RCC)

Abstract Renal Cell Carcinoma (RCC) is the most common type of kidney cancer (85%) of which 75% of the cases involve conventional clear cell RCC (ccRCC). Choice of treatments recommended for clear cell carcinoma and non-clear cell carcinoma are partial nephroctomy (Stage I), radical nephoroctomy (Stage II and III) and chemotherapy (stage IV). Phosphatidylinositol-3- kinase (PI3K) inhibitors are one of the most prospective candidate in the therapy of ccRCC as the PI3CA gene for p110α (a class of the catalytic sub unit of PI3K) is mutated in most of the cases. Hence, PI3K inhibitors like Alpelisib (BYL 719) can be a treatment. But current therapeutic prospects are limited to the fact that RCC is a chemotherapy-resistant cancer type that acts as a barrier for successful treatment with this inhibitor. In addition, of all the other aPKCs, PKC ί/λ and PKC ζ are reported to be frequently overexpressed in most cancer cells and to have different significant roles in tumor progression and carcinogenesis of different type of cancers. Caki-1 metastatic clear cells were treated with PKC ζ inhibitor [8-hydroxynaphthalene-1,3,6-trisulfonic acid] or ζ-stat, Alpelisib and combination of both ζ-stat and Alpelisib at different doses. The results of WST-1 shows that the combination of ζ-stat (7.5 µM) and Alpelisib (10.0 µM) has the most cytotoxicity compared to the single therapy of Alpelisib. Annexin-V/PI assay also suggested that the combination therapy caused greater percentage of apoptosis and cell death compared to the single therapy of Alpelisib. The efflux proteins, (p-glycoprotein (P-gp) and ATP-binding cassette sub-family G member 2 (ABCG2), are responsible for developing cell resistance in Caki-1 cells had reduced expression in the cells when treated with the combination treatment of Alpelisib and ζ-stat. Therefore, combination therapy of Alpelisib and an aPKC inhibitor for metastatic ccRCC can reduce expression of multi drug resistance (MDR) proteins/efflux transporter P-gp and ABCG2. Hence, this combination may be a possible treatment that might help eradicating MDR of ccRCC. Thus, a combination of Alpelisib and an aPKC inhibitor can be a two pronged approach reducing the cell proliferation and resistance. Citation Format: Khandker Mohammad Khalid. A combination therapy of atypical protein kinase inhibitor and phosphatidylinositol-3- kinase inhibitor reduces multidrug resistance in renal cell carcinoma (RCC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1783.

Abstract 3031: Diverse microenvironmental agonists promote a multi drug tolerant persister phenotype CLL and MCL

Abstract Responses to ibrutinib (IBR) or venetoclax (VEN) in Chronic Lymphocytic Leukemia (CLL) or Mantle Cell Lymphoma (MCL) are often partial. We reported synergistic toxicity for the IBR+VEN combination in CLL/MCL ex vivo and initiated an IBR+VEN trial in MCL (NCT02419560). However, we noted variable de novo resistance even to IBR+VEN ex vivo, and this has been found in patients (Tam et al., 2018). We also reported that microenvironmental agonists (CpG-ODN, sCD40L, and IL10; “agonist mix”) rapidly induce de novo resistance to IBR+VEN in CLL/MCL (Jayappa et al., 2017). Here we show that microenvironmental agonists induce multi-drug tolerance to diverse pro-apoptotic drugs (bendamustine, fludarabine, vincristine, inhibitors of Mcl-1, Bcl-xL, and Bcl-2, and BAX activator) including IBR+VEN in CLL PBMCs (N=10). This is mediated by a pre-mitochondrial apoptosis blockade, as BAX activation failed in these cells. CLL cells with an activation phenotype (CD5+/19+/69+) in treatment naive patient PBMCs (N=3) also showed tolerance to several drugs, indicating that multi-drug tolerant cells pre-exist in vivo. To identify extrinsic inducers of drug tolerance, we tested stromal cells, and agonists for TLRs, NOD1/2, CD40, and IL10R for induction of IBR+VEN tolerance. Variable levels of tolerance were noted in most CLL/MCL PBMCs (N=15) cultured with the TLR9 agonist CpG-ODN, sCD40L, or Jurkat cells expressing CD40L. IL10 and HUVEC induced modest levels of drug tolerance in a few CLL/MCL PBMCs, and TLR1/2, TLR7, and NOD1/2 agonists were effective only in MCL. Prior exposure to CpG-ODN enhanced the drug tolerance/proliferation response to sCD40L and vice versa in CLL/MCL (N=8), predicting mutually reinforcing interactions of agonists in vivo. CLL cells exposed to CpG-ODN/CD40L upregulated cognate receptors and/or NFkB proteins downstream, suggesting a mechanism for mutual reinforcement. The agonist mix induced NFkB-dependent over-expression of anti-apoptotic proteins Mcl-1 and Bcl-xL. Consistently, multi-drug tolerance was rescued with NFkB inhibitors (BMS345541, MI-2, bortezomib) or drug combinations that inhibit multiple anti-apoptotic proteins in CLL cells exposed to agonist mix or CD5+/19+/69+ cells without agonists. By analyzing non-cancer (CD5+/19-) cells in patient PBMCs, bortezomib and MALT1 inhibitor MI-2 were selectively toxic to cancer cells, showing their value for clinical testing. In summary, diverse microenvironmental agonists, mainly agonists of TLR9 and CD40, induce multi-drug tolerance in CLL/MCL, which is mediated by NFkB dependent over-expression of multiple anti-apoptotic proteins. Inhibitors of NFkB or drug combinations targeting apoptotic proteins overcame multi-drug tolerance. Thus, durable responses may require drug combinations targeting multiple apoptotic proteins, convergent pathways that induce multi-drug tolerance, and/or agents activating non-apoptotic death. Citation Format: Kallesh D. Jayappa, Vicki L. Gordon, Konrad J. Cios, Christopher G. Morris, Puja C. Arora, Timothy P. Bender, Michael E. Williams, Craig A. Portell, Michael J. Weber. Diverse microenvironmental agonists promote a multi drug tolerant persister phenotype CLL and MCL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3031.

S. Enteritidis and S. Typhimurium Harboring SPI-1 and SPI-2 Are the Predominant Serotypes Associated With Human Salmonellosis in Saudi Arabia.

Non-typhoidal Salmonella (NTS) strains are Gram negative bacterial pathogens that are associated with foodborne illness worldwide. During the process of infection, Salmonella uses two molecular injectisomes known as Type 3 Secretion Systems (T3SS) to secrete virulence factors that are encoded by Salmonella Pathogenicity Island-1 (SPI-1) and SPI-2 into host cells. These secretion systems play a major role in virulence, as shown in various animal models, but little is known about their role in human infections. In Saudi Arabia, NTS strains frequently cause human infections but data regarding these pathogenic strains is fairly limited. The aim of this study was to characterize Salmonella human clinical isolates in Riyadh, Saudi Arabia, by determining their serotype, testing for the presence of SPI-1 and SPI-2 genes and to determine the antibiotic resistance profiles of these strains. Using the rapid Check and Trace Salmonella™ (CTS) system our results demonstrate that S. Enteritidis and S. Typhimurium were the predominant serovars, followed by S. Livingstone, S. Kentucky and S. Poona among a list of 36 serovars reported for the first time in the country. In addition, SPI-1 genes were detected in 99% of the isolates, while the sifA gene (SPI-2) was not detected in 13.5% of the isolates. These results suggest that both the SPI-1 and SPI-2 virulence determinants are important for human infection. Moreover, we report the presence of a Multi-Drug (MDR) carbapenem resistant S. Kentucky isolate harboring the blaOXA−48 gene not reported previously in Saudi Arabia.

Synthesis, Characterization and Antimicrobial Activity of Cu (II), Co (II) and Ni (II) Histidine Complexes

Ternary complexes of histidine amino acid (Schiff base) were synthesized, characterized and tested against multi-drug resistant pathogens. The metal ion centers included Cu (II), Ni (II) and Co (II). These complexes were characterized using physico-chemical and spectroscopic analytical methods. All the complexes are found to be considerably soluble in both polar and non-polar solvents including methanol, ethanol, butanol, acetone, ethyl acetate, and benzene and di ethyl-ether. Electronic Absorption Studies using FT-IR spectrophotometer revealed ν (O-H), ν (C=O), ν (C=N), ν (M -N) and ν (M-O) occurred between 3410 - 3417, 1751 - 1753, 1519 – 1521, 671 – 678, 439 – 470 cm- 1 respectively in complexes and ligand. UV-Visible was further used to elucidate the complexes resulting in transitions characteristics of the ligand and complexes. The Schiff base showed no antimicrobial activity at various therapeutic concentrations. However, the metal complexes exhibited broad spectrum antibiotic activities against the multi-drug resistant pathogens at minimum inhibitory concentration (MIC ≤ 200 µg/ml). The metal complexes showed strong activity against the isolates at medium and high concentrations, the bacteria strains included E.coli , P. aeruginosa, S. typhi and S. aureus and the fungi strains of Candida albicans , Aspergillus flavus and Aspergillus niger . The bioactivity recorded against these multi drug resistant pathogens indicates the potentials of these complexes for further therapeutic studies. Keywords : Histidine complex, synthesis, characterisation, antimicrobial activity, pathogens.

2D carbon nano material based gentamicin nano composite for antibacterial activity against Escherichia coli: A novel strategy towards multidrug resistant bacteria

Multidrug resistance is one of the burning issues in medical sciences as it makes bacteria, able to stop antibiotic, working on it. These resistant strains of bacteria make treatment difficult, costly, with addition of prolonged hospital stay and increase rate of mortality. In the recent years 2D carbon nano composite based drugs has proved its potential, against microbial infections due to their high pay load, and site specific drug delivery. Novel nano composite: combination of-protein synthesis inhibitor: gentamicin, conjugated with efficient nano carrier: graphene could result better in antibiotic resistance, on topical infection caused by multi drug resistant E. coli 1614. This study was primarily based on two stages: conjugation of 2D carbon nano material based gentamicin nanocomposite and it’s drug-carrier interaction studies, using FTIR as a tool. There resulted spectra of FTIR showed no significant interaction of the drug with the chosen nano-carrier used in the nanocomposite formulation. In second phase, screening for antibacterial activity, proved gentamicin loaded graphene nanocomposite as an excellent tool against topical infection caused by multidrug resistance strain of E. coli 1614.

Expression of integrin α-6 is associated with multi drug resistance and prognosis in ovarian cancer.

Ovarian cancer is a serious threat to women's health. Multidrug resistance is a major cause of post-treatment relapse, metastasis, and even mortality. This characteristic severely restricts the survival of patients with ovarian cancer. Integrin α-6 (ITGA6) is a member of the adhesion molecule family that conducts signals through interactions between the extracellular domain and the matrix, serving important roles in cell adhesion-mediated drug resistance, which is considered to have a critical function in ovarian cancer drug resistance. The association between ITGA6 and ovarian cancer multidrug resistance has been investigated only rarely, to the best of our knowledge. Using RT-qPCR and immunohistochemistry, it was identified that ITGA6 is a central drug resistance gene, and that its expression was upregulated in cisplatin-resistant SKOV3 (SKOV3/DDP2), cisplatin-resistant A2780 (A2780/DDP) cells, and in 54 cases of drug-resistant tissues, as compared with in the controls. Furthermore, bioinformatics and text mining performed by Coremine Medical (http://www.coremine.com/medical/#search) confirmed that ITGA6 was significantly associated with ovarian cancer and drug resistance. Additionally, the high expression of ITGA6 is associated with a poor outcome. The present study provides the basis for further understanding the role of ITGA6 in the regulation of drug resistance in ovarian cancer, and demonstrates that it could be a potential marker for the prognosis of ovarian cancer.

Plasmid Curing in Multi-Drug Resistant Hospital and Community Uropathogenic <i>Escherichia coli</i>

Escherichia coli is the most prevalent organism responsible for urinary tract infections (UTIs) in hospital and community sources. The present study was carried out to detect multi drug resistant (MDR) E coli from urine samples and the role of plasmids in drug resistance. One hundred urine samples were collected from the hospital and community within the University of Port Harcourt. Microscopic and chemical examination was carried out on the urine samples. E coli were isolated and antibiotic sensitivity test was carried out on the isolates, the resistant E. coli were cured by acridine orange and further subjected susceptibility testing. Result obtained from the study showed 35% E. coli recovered from community samples and 65% from hospital samples. Antibiotic sensitivity testing before plasmid curing showed high level of resistance to Augmentin (99%), Cefuroxime (92%), Ceftazidime (78%) and Cefixime (71%). The lowest level of resistance was reported in Gentamicin (15%) and Nitrofurantoin (19%). All the isolates were resistant to Augmentin but upon plasmid curing the resistant rate ofisolates to eight antibiotics reduced. Our findings showed that Augmentin and Cefuroxime (62 and 31%) were still resistant after the plasmids of the isolates were cured. For hospital and community sources Nitrofurantoin (1; 0%), Ceftazidime (3; 8%), Ciprofloxacin (1%), Gentamicin (10%) and Ofloxacin (10%). Sixty-two (62) percent of the hospital isolates were resistant to three or more antibiotics while 60% of the community isolates were multidrug resistant. Our study thus concludes that plasmids alone are not responsible for the resistance to antibiotics exhibited by E,coli from urine samples. Antibiotics should be produced to target genes that are responsible for resistance to prevent the spread of drug resistant organisms.Keywords: Antibiotics, Escherichia coli, Multidrug resistant, Plasmid

Panrezistentan pseudomonas aeruginosa izolovan iz kvalitativnog trahealnog aspirata je verovatnije kontaminat nego uzročnik respiratornih infekcija kod pacijenata u intenzivnoj nezi - studija slučaja

Introduction: Differentiating colonization from infection is not straightforward, and sometimes antibiotics are prescribed unnecessarily if a clinician relies only on susceptibility report from microbiology lab, further promoting antimicrobial resistance. Aim: The aim of our study was to investigate whether pandrug-resistant Pseudomonas aeruginosa (PA) isolated from qualitative endotracheal aspirates of ICU patients was primarily external colonization from environmental reservoirs. Subjects and Methods: An instrumental case study was conducted using qualitative research methodology. An ICU with level 2 or 3 of intensive care from Clinical Center Kragujevac, Serbia, was chosen for the case, and research questions were triangulated by direct observation, interviewing personnel of the ICU and by epidemiological survey. Results: Pandrug-resistant PA was present in environment of the ICU because hygiene was not stringently kept. It eventually arrived to respiratory circuits of mechanically ventilated patients and gradually descended to endotracheal tube and trachea. Reliance on qualitative endotracheal aspirate in patients with suspected respiratory tract infection led to diagnosing colonization as infection in 50% of cases with isolation of PA. Inadequate hygiene and avoidance of aseptic working techniques together with understaffing and insufficient funding of the ICUs leads to contamination of personnel and environment with Pseudomonas aeruginosa coming from ill patients. It is then cross-transferred to other patients, who are over-treated with reserve antibiotics due to low specificity of qualitative microbiological analyses and the fact that 50% of patients are only colonized. Conclusions: Pressure made by antimicrobial treatment of colonization creates at first multi drug-, and then pandrug-resistant clones of PA which gradually populate environment of the ICU, becoming serious threat for new patients. This vicious spiral could be broken by improvement of hygiene, provision of enough trained personnel and necessary materials, continuous control of personnel's compliance to working standards for ICUs and by introduction of quantitative microbiological analysis of samples.

Clinical Use of Polymyxin B.

Polymyxin B is another clinically available polymyxin that hasre-emerged in clinical practice to treat infections caused by multi-drug (MDR) or extensively-drug-resistant (XDR) Gram-negative bacteria (GNB). Its chemical structure is very similar to the structure of polymyxin E (colistin). However, since the latter is administered as a prodrug, there are major pharmacokinetic differences between bothpolymyxins that may potentially determine different clinical and microbiological outcomes. Studies addressing clinical or microbiological outcomes in patients treated with polymyxin B for MDR or XDR GNB are reviewed in this chapter.

Frequency and antibiogram of multi-drug resistant pseudomonas aeruginosa in a Tertiary Care Hospital of Pakistan.

Objective:To determine pathogen burden and susceptibility pattern of multi-drug resistant (MDR) Pseudomonas aeruginosa isolates from clinical specimens in Karachi.Methods:It was In-vitro Clinical study, conducted in department of Pharmacology, Ziauddin University, and isolates were collected from various specimens such as pus, tracheal aspiration, wound swab, blood and urine in Microbiology department of Ziauddin Hospital, Nazimabad campus, Karachi. The antibiotic susceptibility pattern was determined by Kirby Bauer Disc diffusion method. Samples were processed as per procedures defined by Clinical and Laboratory Standards Institute (CLSI) guidelines 2018.Results:About 55% were found to be multi drug resistant P. aeruginosa. Majority of the isolates (35.4%) were recovered from the age range 60-80 years. Maximum number of MDR P. aeruginosa was isolated from pus (33.1%) followed by tracheal aspiration (20.6%). Highest sensitivity was seen by colistin (100%) followed by ceftolozane/tazobactam (60%). Least sensitivity was observed with imipenem (19%). However, increase trend of resistance was seen among all antipesudomonal drugs.Conclusion:Increasing frequency of infections due to MDR P. aeruginosa is an emerging threat in our set up which can be prevented by prescribing antibiotics judiciously. Consistent lab detection and surveillance regarding this resistant pathogen is compulsory for providing effective health care to community.

Transporter and Lysosomal Mediated (Multi)drug Resistance to Tyrosine Kinase Inhibitors and Potential Strategies to Overcome Resistance.

Tyrosine kinase inhibitors are a class of chemotherapeutic drugs that target specific protein kinases. These tyrosine kinase inhibitors constitute a relatively new class of drugs which target for instance Bcr-Abl, Epidermal Growth Factor Receptor (EGFR) and Vascular Endothelial Growth Factor Receptor (VEGFR). Despite some initial successes, the overall therapeutic benefit of tyrosine kinase inhibitors in the clinic has been mixed. Next to mutations in the target, multidrug resistance is a major obstacle for which still no clinically effective strategies have been developed. Major mechanisms of multidrug resistance are mediated by drug efflux transporter proteins. Moreover, there is accumulating evidence that multidrug resistance can also be caused by lysosomal sequestration of drugs, effectively trapping tyrosine kinase inhibitors and preventing them from reaching their target. Lysosomal drug sequestration seems to work together with ATP-binding cassette transporters, increasing the capacity of lysosomes to mediate sequestration. Both membrane efflux transporter proteins and lysosomes present potential therapeutic targets that could reverse multidrug resistance and increase drug efficacy in combination therapy. This review describes both mechanisms and discusses a number of proposed strategies to circumvent or reverse tyrosine kinase inhibitor-related multidrug resistance.

Multi drug resistance in severe burn patients by air isolation

Objective To study the difference between multi-drug resistant bacteria in patients with severe burns under air isolation and non-air isolation measures. Methods Sixty severe burn patients were selected and randomly divided into non air isolation group and air separation group by random digits table method with 30 cases each. At 0 days and 14 days in the group, the sputum, the air and the material table in the ward were sampled in the two sets of warp, the multidrug resistant bacteria and the drug resistance were identified. Results At the time of enrollment, 31.67%(19/60) patients were infected with Acinetobacter baumannii and 33.33%(20/60) with Klebsiella pneumoniae. There was no significant difference between the two groups (P > 0.05). Acinetobacter baumannii and Klebsiella pneumoniae were multidrug-resistant bacteria. The results of group, air, surface and sputum culture had significant influence on the infection of multidrug-resistant bacteria (odds ratio: 1.582, 1.265, 2.314, 0.100, 95% confidence interval, P < 0.05). At the 14th day, the infection rate of drug-resistant bacteria cultured in sputum was 50.00% (15/30) in air isolation group and 40.00% (12/30) in non-air isolation group. The difference between the two groups was statistically significant (χ2=-3.962, P < 0.05). Conclusions Air isolation measures can reduce multidrug-resistant bacteria in the surface and air of the ward, and air isolation measures can reduce the incidence of multidrug resistance in severe burn patients. Key words: Air isolation; Severe burn patients; Multidrug resistance

1169. Surveillance of Antibiotic-Resistant Bacteria Reported Among Healthcare-Associated Infections, California, 2011–2017

BackgroundAntibiotic-resistant healthcare-associated infections (HAI) threaten patient safety and public health. HAI reported by California hospitals to the National Healthcare Safety Network include pathogen and antibiotic susceptibility information. We analyzed HAI data to measure regional changes in antibiotic resistance (AR) over time among select bacteria.MethodsWe analyzed central line-associated bloodstream infection (CLABSI) data using log binomial regression models to estimate annual change in the proportion of pathogens resistant to carbapenems, extended-spectrum cephalosporins, methicillin/oxacillin, and multidrug (MDR) combinations for the reporting years 2011–2017. We aggregated HAI CLABSI, catheter-associated urinary tract infection (CAUTI), and surgical site infection (SSI) data in 2-year increments (i.e., 2014–2015, 2016–2017) to assess changes in percent resistance by county when data for 30 or more pathogens were available.ResultsAmong CLABSI reported from 2011 to 2017, there were no significant changes in the proportion of carbapenem-resistant Enterobacteriaceae (CRE) (Figure 1; risk ratio [RR]: 0.97, 95% CI: 0.92, 1.03; P = 0.32), methicillin/oxacillin-resistant S. aureus (MRSA) isolates (RR: 0.98, 95% CI: 0.96, 1.00; P = 0.06) or Pseudomonas aeruginosa with an MDR phenotype (RR: 1.02, 95% CI: 0.95, 1.10; P = 0.54). The proportion of E. coli with MDR and extended-spectrum β-lactamase (ESBL) phenotypes increased by 7% (RR: 1.07, 95% CI: 1.02, 1.12; P < 0.01) and 4% (RR: 1.04, 95% CI: 1.01, 1.08; P = 0.02) per year, respectively. Percentages of AR among aggregated CAUTI, CLABSI and SSI pathogens varied by county and time period (Figures 2 and 3).Figure 1.Figure 2.Figure 3.ConclusionIncreases in antibiotic resistant phenotypes among E. coli, and unchanged prevalence of MDR Pseudomonas aeruginosa, CRE, and MRSA among reported HAI underscore the need for continued infection prevention and antibiotic stewardship efforts in California. Local public health departments can use these analyses to target coordinated AR prevention initiatives with healthcare facilities in their regions.Disclosures All authors: No reported disclosures.

RETRACTED ARTICLE:Flavonoids modulate multidrug resistance through wnt signaling in P-glycoprotein overexpressing cell lines

BackgroundWnt signaling has been linked with P-glycoprotein (P-gp) overexpression and which was mainly mediated by β-catenin nuclear translocation. Flavonoids have already been reported as modulators of the Wnt/β-catenin pathway and hence they may serve as promising agents in the reversal of P-gp mediated cancer multi drug resistance (MDR).MethodsIn this study, we screened selected flavonoids against Wnt/β-catenin signaling molecules. The binding interaction of flavonoids (theaflavin, quercetin, rutin, epicatechin 3 gallate and tamarixetin) with GSK 3β was determined by molecular docking. Flavonoids on P-gp expression and the components of Wnt signaling in drug-resistant KBCHR8–5 cells were analyzed by western blotting and qRT-PCR. The MDR reversal potential of these selected flavonoids against P-gp mediated drug resistance was analyzed by cytotoxicity assay in KBCHR8–5 and MCF7/ADR cell lines. The chemosensitizing potential of flavonoids was further analyzed by observing cell cycle arrest in KBCHR8–5 cells.ResultsIn this study, we observed that the components of Wnt/β-catenin pathway such as Wnt and GSK 3β were activated in multidrug resistant KBCHR8–5 cell lines. All the flavonoids selected in this study significantly decreased the expression of Wnt and GSK 3β in KBCHR8–5 cells and subsequently modulates P-gp overexpression in this drug-resistant cell line. Further, we observed that these flavonoids considerably decreased the doxorubicin resistance in KBCHR8–5 and MCF7/ADR cell lines. The MDR reversal potential of flavonoids were found to be in the order of theaflavin > quercetin > rutin > epicatechin 3 gallate > tamarixetin. Moreover, we observed that flavonoids pretreatment significantly induced the doxorubicin-mediated arrest at the phase of G2/M. Further, the combinations of doxorubicin with flavonoids significantly modulate the expression of drug response genes in KBCHR8–5 cells.ConclusionThe present findings illustrate that the studied flavonoids significantly enhances doxorubicin-mediated cell death through modulating P-gp expression pattern by targeting Wnt/β-catenin signaling in drug-resistant KBCHR8–5 cells.

Phenotypic Assays for Detection of AmpC and MBL Producers among the Clinical Isolates of Multi Drug Resistant Pseudomonas aeruginosa

Objectives: In order to determine the prevalence of multi-drug resistance along with AmpC and metallo-β-lactamase producing P. aeruginosa, a six month cross-sectional study was carried out at Shahid Gangalal National Heart Center.Methods: A total of 756 clinical specimens were analyzed for bacteriological profile. The bacterial isolates were identified by cultural and biochemical techniques. Antibiotic susceptibility testing of the isolates was performed by Kirby-Bauer disc diffusion method. MDR isolates were screened and tested for MBL and AmpC production. Ceftazidime resistant isolates were tested for MBL and Cefoxitin resistant isolates for AmpC.Results: Among all the clinical samples analyzed, P. aeruginosa was detected in 75 samples (9.92%). Antibiotic susceptibility testing showed Imipenem as the most effective drug with susceptibility of 76% followed by Piperacillin-Tazobactam (74.7%) and Piperacillin (41.3%). Out of 75 P. aeruginosa isolates, 53 (70.6%) of them were found to be resistant to at least three out of four anti-pseudomonal agents, thus were considered as MDR. Out of 53 multi-drug resistant P. aeruginosa (MDRPA), all were resistant to ceftazidime whereas 85% (45/53) were resistant to cefoxitin. Out of 53 isolates, 11 (20.75%) showed positive result for MBL. Similarly, 7 out of 45 i.e. 13.2% were found to be AmpC producers.Conclusion: This study signified the high prevalence of MDRPA which is an alarming rate. Also multiple β-lactamase producing P. aeruginosa were detected which can further complicate the treatment options. Regular monitoring of antibiotic susceptibility and rational use of antibiotics would be helpful in eliminating the outbreaks of multiple β-lactamase producing MDRPA.

Association of Antibiotic and Heavy Metal Resistant Bacteria Screened from Wastewater

Wastewater treatment plant is a potential reservoir contributing to the evolution and spread of heavy metal and antibiotic resistant bacteria. The pollutants such as biocides, antibiotics, heavy metals are to be feared for as they have been known to evoke resistance in microorganisms in such polluted environment. The aim of this study was to the isolate bacteria from the treated wastewater and assess the resistance pattern of the isolates against antibiotics and heavy metals. Grab sampling was performed from April to June 2017, from the treated effluent from the secondary treatment plant. To assess the resistance pattern for antibiotic(s) and heavy metal(s), antibiotic susceptibility test and minimum inhibitory concentration by cup well method were performed respectively. Staphylococcus aureus, Enterococcus faecalis, Citrobacter freundii, Escherichia coli, Enterobacter aerogenes, Proteus mirabilis, P. vulgaris, Salmonella Typhi, Pseudomonas aeruginosa were isolated. Multi drug and heavy metal resistant isolates were screened. Fisher’s exact test revealed that there is a significant association (p&lt; 0.001) between antibiotic resistance pattern and resistance patterns at dilution of 2500 g/L (25%). Cramer’s V test revealed that the effect size of antibiotic resistance pattern and heavy metal resistance pattern at dilution 2500 g/L is medium. P. aeruginosa was able to resist the metal concentration up to 10000 g/L (100%) dilution of Fe++. Heavy metal resistant bacteria can be safely used to lower chemical concentration in the environment once their harmful genes are edited, knocked etc. so that risks of evoking antibiotic resistance could be minimized.

Targeting Nucleotide Binding Domain of Multidrug Resistance-associated Protein-1 (MRP1) for the Reversal of Multi Drug Resistance in Cancer

Multidrug resistance (MDR) is the major cause, by which cancer cells expel the drugs out, developing a challenge against the current chemotherapeutic drugs regime. This mechanism is attributed to the over expression of ABC transporters like MRP1 on the surface of cells. Since nucleotide binding domains (NBD) of ABC transporters are the site of ATP binding and hydrolysis, thereby in this study we have targeted NBD1 of MRP1using molecular docking and molecular dynamic simulations (MDS). The compounds present in the FDA approved library were docked against NBD1 of the human multidrug resistance associated protein 1 (PDB ID: 2CBZ). For the docking studies, Standard Precision and Extra Precision methods were employed. After the EP docking studies, ligands showed an extremely low docking score that was indicative of very high binding affinity of the ligands to the NBD. Apart from the low docking score, another short listing criterion in simulation studies was the interaction of incoming ligand with the desired conserved residues of NDB involved in ATP binding and hydrolysis. Based on these measures, potassium citrate (DB09125) and technetium Tc-99m medronate (DB09138) were chosen and subjected to 100 ns simulation studies. From the MDS study we concluded that between these two compounds, potassium citrate is a better candidate for targeting MRP1.