Measurement of energy and directional distribution of neutron ambient dose equivalent for the 7Li(p,n)7Be reaction

Double differential neutron fluence distributions were measured in the 7Li(p,n)7Be reaction for proton beam energies 7, 9 and 12 MeV. Seven liquid scintillator based detectors were employed to measure neutron fluence distributions using the Time of Flight technique. Neutron ambient dose equivalents were determined from the measured fluence distribution using ICRP (International Commission on Radiological Protection) recommended fluence to dose equivalent conversion coefficients. Neutron dose equivalents were also measured using a conventional BF3 detector based REM counter. Ambient dose equivalent measured by the REM counter is found to be in agreement with that determined from the neutron fluence spectra within their uncertainties. Angular distributions of the ambient dose equivalents were also determined from the measured fluence distributions at different angles.

Antibiotic Potentiation as a Promising Strategy to Combat Macrolide Resistance in Bacterial Pathogens

Antibiotics, which hit the market with astounding impact, were once called miracle drugs, as these were considered the ultimate cure for infectious diseases in the mid-20th century. However, today, nearly all bacteria that afflict humankind have become resistant to these wonder drugs once developed to stop them, imperiling the foundation of modern medicine. During the COVID-19 pandemic, there was a surge in macrolide use to treat secondary infections and this persistent use of macrolide antibiotics has provoked the emergence of macrolide resistance. In view of the current dearth of new antibiotics in the pipeline, it is essential to find an alternative way to combat drug resistance. Antibiotic potentiators or adjuvants are non-antibacterial active molecules that, when combined with antibiotics, increase their activity. Thus, potentiating the existing antibiotics is one of the promising approaches to tackle and minimize the impact of antimicrobial resistance (AMR). Several natural and synthetic compounds have demonstrated effectiveness in potentiating macrolide antibiotics against multidrug-resistant (MDR) pathogens. The present review summarizes the different resistance mechanisms adapted by bacteria to resist macrolides and further emphasizes the major macrolide potentiators identified which could serve to revive the antibiotic and can be used for the reversal of macrolide resistance.

Antimicrobial resistance heterogeneity among multidrug-resistant Gram-negative pathogens: Phenotypic, genotypic, and proteomic analysis

Microbes evolve rapidly by modifying their genomes through mutations or through the horizontal acquisition of mobile genetic elements (MGEs) linked with fitness traits such as antimicrobial resistance (AMR), virulence, and metabolic functions. We conducted a multicentric study in India and collected different clinical samples for decoding the genome sequences of bacterial pathogens associated with sepsis, urinary tract infections, and respiratory infections to understand the functional potency associated with AMR and its dynamics. Genomic analysis identified several acquired AMR genes (ARGs) that have a pathogen-specific signature. We observed that blaCTX-M-15, blaCMY-42, blaNDM-5, and aadA(2) were prevalent in Escherichia coli, and blaTEM-1B, blaOXA-232, blaNDM-1, rmtB, and rmtC were dominant in Klebsiella pneumoniae. In contrast, Pseudomonas aeruginosa and Acinetobacter baumannii harbored blaVEB, blaVIM-2, aph(3'), strA/B, blaOXA-23, aph(3') variants, and amrA, respectively. Regardless of the type of ARG, the MGEs linked with ARGs were also pathogen-specific. The sequence type of these pathogens was identified as high-risk international clones, with only a few lineages being predominant and region-specific. Whole-cell proteome analysis of extensively drug-resistant K. pneumoniae, A. baumannii, E. coli, and P. aeruginosa strains revealed differential abundances of resistance-associated proteins in the presence and absence of different classes of antibiotics. The pathogen-specific resistance signatures and differential abundance of AMR-associated proteins identified in this study should add value to AMR diagnostics and the choice of appropriate drug combinations for successful antimicrobial therapy.

Imipenem and meropenem influence the Las/Rhl quorum-sensing systems in clinical isolates of Pseudomonas aeruginosa

The present study was conducted to study the influence of imipenem and meropenem at subinhibitory concentration on the transcriptional response of Las/Rhl quorum-sensing systems in isolates of Pseudomonas aeruginosa. In the present study, six representative carbapenem nonsusceptible clinical isolates of P. aeruginosa were obtained. The agar dilution method was used to determine the minimum inhibitory concentration against imipenem and meropenem. The bacterial isolates were then cultured up to the early log phase in fresh Luria Bertani (LB) broths at 37°C with and without 2 µg mL-1 imipenem and meropenem, respectively. mRNA was then isolated from the bacterial isolates and was immediately reverse-transcribed to cDNA. The relative quantity of the expression of the lasI, lasR, rhlI, and rhlR genes was assessed by quantitative real-time Polymerase Chain Reaction (PCR) using the ΔΔCt method. The transcriptional response of the lasI and lasR genes was upregulated at subinhibitory concentration of meropenem. In contrast, the transcriptional response of the lasI, lasR, and rhlR genes was downregulated at subinhibitory concentration of imipenem as compared to the expression in untreated isolates. The data obtained in the current study showcased the ability of imipenem and meropenem to influence the response of the quorum-sensing genes at subinhibitory concentration.

Novel molecular hybrid geometric-harmonic-Zagreb degree based descriptors and their efficacy in QSPR studies of polycyclic aromatic hydrocarbons

The physicochemical characteristics of polycyclic aromatic compounds critical to environmental modelling such as octanol partition coefficients, solubility, lipophilicity, polarity and several equilibrium constants are functions of their underlying molecular structures, prompting the development of mathematical models to predict such characteristics for which experimental results are difficult to obtain. We propose twelve novel descriptors derived from geometric, harmonic and Zagreb degree-based descriptors and then test the effectiveness of these descriptors on a data set consisting of 55 benzenoid hydrocarbons of environmental importance. Our computations show that the proposed descriptors have a good linear correlation and predictive power when compared to the degree and distance type descriptors. We have also derived the QSPR expressions for four properties of a large series of polycyclic aromatics arising from circumscribing coronenes and show that a scaling factor can be deduced to derive physicochemical properties of such series up to 2D graphene sheets.

β-Lactam potentiators to re-sensitize resistant pathogens: Discovery, development, clinical use and the way forward

β-lactam antibiotics are one of the most widely used and diverse classes of antimicrobial agents for treating both Gram-negative and Gram-positive bacterial infections. The β-lactam antibiotics, which include penicillins, cephalosporins, monobactams and carbapenems, exert their antibacterial activity by inhibiting the bacterial cell wall synthesis and have a global positive impact in treating serious bacterial infections. Today, β-lactam antibiotics are the most frequently prescribed antimicrobial across the globe. However, due to the widespread use and misapplication of β-lactam antibiotics in fields such as human medicine and animal agriculture, resistance to this superlative drug class has emerged in the majority of clinically important bacterial pathogens. This heightened antibiotic resistance prompted researchers to explore novel strategies to restore the activity of β-lactam antibiotics, which led to the discovery of β-lactamase inhibitors (BLIs) and other β-lactam potentiators. Although there are several successful β-lactam-β-lactamase inhibitor combinations in use, the emergence of novel resistance mechanisms and variants of β-lactamases have put the quest of new β-lactam potentiators beyond precedence. This review summarizes the success stories of β-lactamase inhibitors in use, prospective β-lactam potentiators in various phases of clinical trials and the different strategies used to identify novel β-lactam potentiators. Furthermore, this review discusses the various challenges in taking these β-lactam potentiators from bench to bedside and expounds other mechanisms that could be investigated to reduce the global antimicrobial resistance (AMR) burden.

Chest HRCT Severity Scores among Hospitalized Patients with COVID-19

Corona Virus Disease 2019 (COVID-19) was declared a pandemic in March 2020. This global health crisis caused thousands of pneumonia related death all over the world since December 2019. RT-PCR is the primary test for diagnosis of COVID-19, though its sensitivity and specificity is variable. Several studies revealed that chest HRCT complements RT-PCR in highly suspected cases or in false negative RT-PCR and helps to gauge disease severity. This study was carried out with an aim to find out the severity scores of chest HRCT in hospitalized patients with COVID-19. This cross sectional descriptive type of observational study was carried out at COVID-19 unit of Sylhet Women's Medical College Hospital, Bangladesh from April 2021 to September 2021. Data were collected from purposively selected 204 patients with COVID-19 by face to face interview, chest HRCT and necessary laboratory investigations. Informed written consent was taken from the participants of the study at the beginning of the interview. Data were analyzed by using SPSS version 21.0. The results of the study showed that mean age of the patients with COVID-19 was 57.9 years with a standard deviation of ±15.8 years. Majority of them (121, 59.3%) were female and the remaining (83, 40.7%) were male. Regarding co-morbidities it was found that each 115 (56.4%) patients were hypertensive and diabetic. Thirty five (16.2%) had ischemic heart disease; 3(1.5%) had congestive cardiac failure and 2(1.0%) had asthma. One (0.5%) patient has atrial fibrillation. In case of 160(78.4%) RT-PCR confirmed patients with COVID-19, chest HRCT was found positive and in 44(21.6%) it was found negative. Among the positive cases mild (7 or less) chest HRCT score was found in 26(12.7%) patients; moderate (8-17) score was found in highest number of patients (128, 62.7%) and severe (18 or more) chest HRCT score was found in 6(2.9%) patients with COVID-19. Chi-square test was carried out to assess the relation of chest HRCT scores with age group, sex, troponin-I, D-Dimer and clinical outcomes within CCU but statistically significant relation was not found (p>0.05). The negative scans were highest (20, 9.8%) in the age group of 41-60 years. Mild, moderate and severe chest HRCT scores was found highest in the age group of 61-80 years (13, 6.4%; 51, 25.0% and 5, 2.5% respectively) (p=0.508). Chest HRCT scans were negative in 18(8.8%) male and 26(12.7%) female. Mild scores were equally distributed between each sex i.e. male 13(6.4%) and female 13(6.4%). Both moderate and severe scores were found more in female (77, 37.7% and 5, 2.5% respectively) than male (51, 25.0% and 1, 0.5% respectively) (p=0.492). Negative chest HRCT scans, mild, moderate and severe scores-all were found more in patients with elevated D-Dimer (p=0.194). Among 204 patients one (0.5%) died in the CCU who had mild score of chest HRCT (p=0.076) but highly elevated Troponin-I (21.70ng/mL). Chest HRCT was found positive among 78.4% of patients with COVID-19 confirmed by RT-PCR. Chest HRCT can help physicians to detect suspected cases and to assess the severity and outcome of the disease. However, further research is recommended to clarify the role of chest HRCT in assessing severity of COVID-19 and prediction of prognosis.

OP0095 SINGLE-CELL RNA SEQUENCING REVEALS POTENT ANTI-INFLAMMATORY AND ANTIFIBROTIC ACTIVITIES OF DIMETHYL-ALPHA-KETOGLUTARATE ON EXPLANTED SKIN FROM PATIENTS WITH SYSTEMIC SCLEROSIS

Background

Activated fibroblasts are the main drivers of skin fibrosis in SSc. We have recently identified dimethyl alpha-ketoglutarate (dm-aKG) as a potential repressor of myofibroblast differentiation and profibrotic activity in cultured skin fibroblasts.

Objectives

To further analyse the clinical translation of our findings by investigating the antifibrotic capacity of dm-aKG on explanted skin biopsies from SSc patients.

Methods

We cultured forearm punch skin biopsies from SSc patients (n=10) for 24h ex vivo in the presence/absence of 6 mM dm-aKG. Thereafter, skin biopsies (n=4) were dissociated into single cells using a combined mechanical-enzymatic dissociation protocol, followed by single cell (sc)RNA-seq library preparation (10x Genomics) and sequencing (Illumina, NovaSeq6000, 50,000 reads/cell). We mapped the scRNA-seq reads to the reference genome GRCh38.p13 and analysed the data with R/Bioconductor tools. We deconvoluted cell types in bulk skin transcriptomes from SSc cohorts (GSE: 45485, 59785, 9285, 32413) using human skin scRNA-seq data1. The secretion of IL-6, procollagen-1, PRO-C1 (N-terminal type I collagen pro-peptide), C1M (MMP-degradation fragment of type I collagen), and fibronectin (FBN-C) from cultured skin (n=10) was measured in supernatants by ELISA. We analysed gene and protein expression in TGFβ-activated healthy and SSc dermal fibroblasts (DF, n=10) treated or not with dm-aKG using qPCR, Western blot and ELISA. Contractile properties of DF were assessed by gel contraction assay. Traction forces generated by DF were determined by reference-free traction force microscopy.

Results

Dissociated cultured SSc skin exhibited comparable cell yield and viability in the presence (20,203; 89%) and absence (25,280; 93%) of dm-aKG, respectively. scRNA-seq skin analysis included 20,869 high quality single cell profiles segregating into 10 distinct skin cell populations (Figure 1A). This analysis demonstrated decreased proportion of fibroblasts and increased proportion of keratinocytes in dm-aKG treated skin (p<0.05; Figure 1B). Among skin cell types, skin fibroblasts exhibited the largest amount of differentially expressed genes upon dm-aKG treatment (44%, n=779, x-fold>0.5, FDR<0.05), suggesting that these cells are key targets of dm-aKG therapy in SSc skin. We identified inflammatory/cytokine signalling (hub genes IL6, STAT1) and extracellular matrix (ECM) organization (hub genes MMP1, ITGB3) as top downregulated biological processes in fibroblasts in dm-aKG treated SSc skin (Figure 1C), coinciding with a decreased abundance of proinflammatory skin fibroblast subpopulation. Specifically, these cells were identified as the main source of IL6 (Figure 1D) and were enriched in SSc skin as revealed by deconvolution analysis of skin transcriptomes. Furthermore, dm-aKG reduced the secretion of IL-6, procollagen-1 and C1M, but not pro-C1 and FBN-C, from cultured skin explants. In cultured DF, dm-aKG blocked the inflammatory (IL-6, pSTAT3), profibrotic (aSMA, Fibronectin, Procollagen-1, Pro-C1) and contractile activities, and significantly diminished traction forces exerted by DF on the matrix substrate.

Figure 1.

scRNA-seq – comparison of untreated and dm-aKG treated paired skin biopsies. (A) UMAP plot with annotated skin cells, (B) differential abundance of main skin cell types, (C) volcano plot of DE genes with top downregulated gene ontology (GO) pathways in dm-aKG treated skin fibroblasts, (D) IL6 expression in untreated (blue) and treated (pink) skin fibroblasts.

Conclusion

Dm-aKG broadly interferes with inflammatory and ECM organizational activities of skin fibroblasts in culture and in explanted skin from SSc patients. These results confirm that dm-aKG might represent a potential new therapeutic approach for efficient targeting of skin inflammation and fibrosis in SSc.

References

[1]He H et al. J Allergy Clin Immunol 2020

Acknowledgements

This work was supported by a research grant from FOREUM Foundation for Research in Rheumatology and University Medical Centre Ljubljana.

Disclosure of Interests

Blaž Burja: None declared, Dominique Paul: None declared, Reto Gerber: None declared, Sam G. Edalat: None declared, Muriel Elhai Speakers bureau: BMS, Elena Pachera: None declared, Rahel S. Zingg: None declared, Francesca Michela Pramotton: None declared, Sofie Falkenløve Madsen: None declared, Kristina Buerki: None declared, Giampietro Costanza: None declared, Michael Whitfield: None declared, Anne-Christine Bay-Jensen: None declared, Snežna Sodin-Šemrl: None declared, Matija Tomsic: None declared, Gabriela Kania: None declared, Hubert Rehrauer: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Ziga Rotar: None declared, Mark Robinson: None declared, Katja Lakota: None declared, Mojca Frank Bertoncelj: None declared.

Elevated expression of rsmI can act as a reporter of aminoglycoside resistance in Escherichia coli using kanamycin as signal molecule

We aimed to design and analyse expressional response of endogenous and exogenous 16S rRNA methyl transferase genes under sub inhibitory concentration stress of different clinically relevant aminoglycoside antibiotics in Escherichia coli to identify an endogenous marker. One hundred twenty nine aminoglycoside resistant E. coli of clinical origin were collected for detection of 16S rRNA methyl transferase genes by PCR assay and each gene type was cloned within E. coli JM107. Parent isolates were subjected to plasmid elimination by SDS treatment. Expression analysis of both acquired and endogenous 16S rRNA methyl transferase genes were performed by quantitative real-time PCR in clones and parent isolates under aminoglycoside stress (4 mg/L). Majority of the isolates were harbouring rmtC (35/129), followed by rmtB (32/129), rmtA (21/129), rmtE (13/129), armA (11/129) rmtF (9/129) and rmtH (8/129). Plasmid was successfully eliminated for all the isolates with 6% of SDS. Expression analysis indicates that kanamycin, tobramycin and netilmicin stress could increase the expression of 16S rRNA methyltransferese genes. In the presence of kanamycin stress the expression of rsmI was consistently elevated for all the wild type isolates and clones tested. Except for isolates harbouring rmtB and rmtC expression of rsmE and rsmF was increased in the presence of all aminoglycosides. For all the cured mutants it was apparently observed that expression of endogenous methyl transferases were marginally increased. Elevated expression of constitutive rsmI can be used as a potential biomarker for detection of acquired 16S rRNA methyl transferase mediated aminoglycoside resistance by using sub inhibitory concentration of kanamycin as signal molecule.

Antimicrobial resistance in patients with suspected urinary tract infections in primary care in Assam, India

Objectives

We investigated the prevalence and diversity of antimicrobial resistance in bacteria isolated from urine samples of community-onset urinary tract infection (UTI) patients in southern Assam, India.

Methods

Freshly voided midstream urine samples were collected from patients attending primary healthcare centres, with the patients’ epidemiological data also recorded. Species identification was confirmed using a VITEK 2 compact automated system. Phenotypic confirmation of ESBLs was performed using the combined disc diffusion method (CLSI 2017) and carbapenemase production was phenotypically characterized using a modified Hodge test. Common ESBLs and carbapenem-resistance mechanisms were determined in Escherichia coli isolates using PCR assays. Incompatibility typing of the conjugable plasmids was determined by PCR-based replicon typing; the phylotypes and MLSTs were also analysed.

Results

A total of 301 (59.7%) samples showed significant bacteriuria along with symptoms of UTI and among them 103 isolates were identified as E. coli of multiple STs (ST3268, ST3430, ST4671 and others). Among them, 26.2% (27/103) were phenotypically ESBL producers whereas 12.6% (13/103) were carbapenemase producers. This study describes the occurrence of diverse ESBL genes—bla_CTX-M-15, bla_SHV-148, bla_PER-1 and bla_TEM—and two E. coli isolates carrying the bla_NDM-1 carbapenemase gene. ESBL genes were located within transconjugable plasmids of IncP and IncF type whereas bla_NDM-1 was carried in an IncF_repB type plasmid.

Conclusions

This study illustrates the high rate of MDR in E. coli causing UTI in primary care in rural Assam. UTIs caused by ESBL- or MBL-producing bacteria are very difficult to treat and can often lead to treatment failure. Thus, future research should focus on rapid diagnostics to enable targeted treatment options and reduce the treatment failure likely to occur with commonly prescribed antibiotics, which will help to combat antimicrobial resistance and the burden of UTIs.

Comparative Analysis of Municipal Solid Waste Management in Kochi and Indore

Conventionally, the general understanding of Municipal Solid Waste (MSW) management is collecting solid waste and its disposal through its developed channels or outside contracts. However, depending upon the situation and context, the definition of MSW varies between countries across the globe. For instance, in countries like Singapore and Japan, Municipal Solid Waste is defined as general waste. However, while categorizing the general waste, the industrial waste component is considered for Singapore and not for Japan. Similarly, different countries associate different definitions for MSW and it becomes a difficult challenge to suggest a single unified definition applicable for all countries. This paper aims to do a comparative analysis of Waste management in Tier-II cities of India, Kochi and Indore. Kochi is ranked 372nd and the latter 1st according to the latest Swachh Survekshan undertaken as part of the Swachh Bharat Abhiyan (Urban) by the Ministry of Housing and Urban Affairs. This paper highlights what the key elements missing out in the management of waste in Kochi from the reference perspective of Indore and identifying the measures Kochi needs to undertake to improve its ranking among the cleanest city in India are.

Report of a carbapenemase gene blaIMP-4 in multi-drug resistant Escherichia coli from sewage water: A threat on clinical-environmental interphase

Acquired carbapenemases pose a significant role in the dissemination of antimicrobial-resistant Enterobacteriaceae and in this study we have identified the occurrence of bla_IMP-4 in E. coli isolate from a sewage outfall located nearby a secondary health Centre. It was found to co-existed with bla_CTX-M-15 located within a self-conjugable plasmid of IncF type. The current study underscores environment as a potential reservoir of carbapenem resistance and the need of the hour is to track and check dissemination of resistance in environment, human and agricultural settings.

Human carriage of cefotaxime-resistant Escherichia coli in North-East India: an analysis of STs and associated resistance mechanisms

OBJECTIVES

To determine the prevalence of Escherichia coli STs and associated resistance mechanisms carried by the community in North-East India.

METHODS

E. coli (108) were isolated from sewage collected from 19 sites across the city of Silchar by plating on MacConkey agar with/without selection (50 mg/L cefotaxime). Species identification was confirmed by MALDI-TOF MS for 82 isolates. Common resistance mechanisms were determined by WGS of pooled E. coli isolates. PFGE combined with specific probes determined the presence of common resistance mechanisms in all isolates. Phylotypes, multilocus STs, core-genome multilocus STs, resistance genes and virulence genes were determined by in silico analysis of 38 genomes.

RESULTS AND CONCLUSIONS

Analysis of isolates collected without selection (n=33) indicated that cefotaxime resistance in E. coli was 42% (14/33) and estimated meropenem resistance at 9%. The remaining 58% (19/33) were additionally susceptible to ampicillin, trimethoprim, ciprofloxacin and aminoglycosides. The most common ST among the cefotaxime-resistant E. coli was ST167 (29%), followed by ST410 (17%) and ST648 (10%). E. coli ST131 was absent from the collection. Sixty-three isolates were resistant to cefotaxime and harboured blaCTX-M-15 [54% (34/63)] or blaCMY-42 [46% (29/63)], of which 10% (6/63) harboured both genes. Carbapenem resistance was due to blaNDM-5, found in 10/63 cefotaxime-resistant isolates, and/or blaOXA-181, found in 4/63 isolates. NDM-5 was encoded by IncX3 and/or IncFII plasmids and CMY-42 was mostly encoded by IncI plasmids. NDM-5 appears to have replaced NDM-1 in this region and CMY-42 appears to be in the process of replacing CTX-M-15.

Transcriptional Analysis of IncFrepB-Mediated blaOXA-48-Positive Plasmid Characterized from Escherichia coli ST448

Objectives: To investigate the transcriptional response of bla_OXA-48 and the copy number alteration of IncF_repB plasmid carrying bla_OXA-48 under an antibiotic concentration gradient. Methods: Escherichia coli strains harboring bla_OXA-48 on an IncFrep_B plasmid were isolated from Silchar Medical College and Hospital, Silchar, India. Sequence type and common resistance determinants were determined by PCR assay. Plasmid copy number alteration and the transcriptional expression of bla_OXA-48 under different antibiotic pressures were determined by quantitative real-time PCR, and the relative fold change was measured by the ΔΔCT method. Results and Conclusion: The plasmid that carried bla_OXA-48 in E. coli ST448 was characterized as IncFrep_B and found to be conjugatively transferable. The isolates were found to coexist with bla_NDM-1 within the IncX3-type plasmid. It was observed that the copy number and transcriptional response of bla_OXA-48 were directly proportional to the increasing concentration of meropenem and ertapenem, whereas in the case of imipenem, it was reversed. The identification of bla_OXA-48 through IncF_repB-type plasmid in this study indicates the potential route of spread of this resistance determinant in this area and also the insights we gained from the transcriptional changes of bla_OXA-48 in response to different antibiotic pressures could also facilitate the development of novel or alternative therapeutic options needed for multidrug-resistant infections.

Use of fluorescence foldscope as an effective tool for detection of biofilm formation in Pseudomonas aeruginosa

Purpose

Pseudomonas aeruginosa is an opportunistic pathogen with biofilm-forming ability, by the virtue of which they can evade the immune response and antimicrobial chemotherapy. Several methods have been designed for the detection of biofilms but require sophisticated instrumentation and expertise. The present study, therefore, used an improvised device, 'fluorescence foldscope' which is an origami-based fluorescence microscope as an easy and effective tool to detect biofilm formation.

Methodology

Three representatives of P. aeruginosa of clinical origin were taken for the study along with two reference strains PA01 and ATCC27853. The strains were cultured in Luria Bertani (LB) broth with and without carbapenem (imipenem and meropenem) and cephalosporin (ceftazidime, cefotaxime and ceftriaxone) pressure, respectively. The cultures were diluted to 1:100 in LB; seeded with sterile glass slides at 90° angle and incubated for 5 consecutive days. The slides were observed with fluorescence foldscope.

Results

Fluorescence emission was observed in two test isolates CD1 and CD2 at 48 and 72 h, respectively, whereas no fluorescence was observed in CD3. The fluorescence observed in the isolates was not affected by 2 μg/ml carbapenem pressure, while with 2 μg/ml ceftazidime stress, a change in fluorescence was observed in CD2 in comparison to the fluorescence observed under normal growth condition.

Conclusion

Fluorescence foldscopy is an effective and reliable tool for the detection of biofilm formation in clinical isolates of P. aeruginosa under different laboratory conditions. Biofilm-forming P. aeruginosa worsens the medical condition and is difficult to eradicate. The present study came up with an effective and reliable tool for the detection of biofilm formation in clinical isolates of P. aeruginosa.

Rationale and study design for lifestyle intervention in preparation for pregnancy (LIPP): A randomized controlled trial

INTRODUCTION

Maternal obesity increases neonatal risk for obesity and metabolic syndrome later in life. Prior attempts to break this intergenerational obesity cycle by limiting excessive gestational weight gain have failed to reduce neonatal adiposity. Alternatively, pre-conception lifestyle interventions may improve the in utero metabolic milieu during early pregnancy leading to improved fetal outcomes. This randomized controlled trial (RCT) is evaluating whether a lifestyle intervention to reduce weight and improve maternal metabolism in preparation for pregnancy (LIPP) attenuates neonatal adiposity, compared to standard medical advice.

MATERIAL AND METHODS

Overweight/class 1 obese women after a previous pregnancy, ~12 weeks postpartum, preparing for a subsequent pregnancy, will be block randomized (1:1) to either LIPP or standard of care in a parallel design. Randomization is stratified by lactation status and overweight vs. class 1 obesity. The LIPP program consists of intensive short-term weight loss followed by weight maintenance until conception using supervised exercise and a low glycemic Mediterranean diet.

PRIMARY OUTCOMES

Group differences in neonatal adiposity at birth assessed by PEA POD and placental mitochondrial lipid metabolism.

SECONDARY OUTCOMES

Group differences in maternal pregravid and gestational body composition, insulin sensitivity, β-cell function, fasting metabolic and inflammatory biomarkers, and overall quality of life. Exploratory outcomes include umbilical cord blood insulin resistance, lipid profile and inflammation.

DISCUSSION

This RCT will determine the efficacy of maternal weight loss prior to pregnancy on reducing neonatal adiposity. Findings may change standard obstetrical care by providing Level 1 evidence on lifestyle interventions improving neonatal outcomes for women planning for pregnancy.

CLINICAL TRIAL REGISTRATION

NCT03146156.

Distribution of carbapenem resistant Acinetobacter baumannii with blaADC-30 and induction of ADC-30 in response to beta-lactam antibiotics

A wide range of intrinsic Acinetobacter-derived cephalosporinases (ADC) along with other carbapenemases has now been detected in Acinetobacter baumannii leaving clinicians with few treatment options. The present study reports the spread of ADC-30 co-producing KPC-2 along with other β-lactamases among carbapenem resistant A. baumannii strains obtained from ICU patients in two Indian hospitals. Primer extension analysis revealed higher transcript level of the ADC gene when induced with cefoxitin at 8 μg/ml (170 fold), ceftriaxone at 8 μg/ml (136 fold), ceftazidime at 4 μg/ml (65 fold), cefepime at 8 μg/ml (77 fold) and aztreonam at 8 μg/ml (21 fold) when compared with the basal level without antibiotic pressure. Slight increase in expression of bla_ADC-30 when induced with imipenem and meropenem at 0.25 μg/ml (3 and 6 fold) was observed and may help in conferring resistance to carbapenem. MLST analysis revealed the circulation of A. baumannii sequence types ST188, ST386, ST583 and ST390 in these hospitals.

DURABLE RESPONSE IN A CASE OF METASTATIC ANAPLASTIC THYROID CANCER USING A COMBINATION OF TYROSINE KINASE INHIBITORS AND A CHECK POINT INHIBITOR

Anaplastic thyroid cancer (ATC) is a highly uncommon (less than 2% of thyroid malignancies) and aggressive type of cancer, with aggressive behavior and, therefore, exhibiting poor prognosis. ATC tumors are automatically labeled as stage IV disease regardless of standard criteria such as tumor burden or metastasis. ATC tumors require a diversified treatment approach that includes surgical resection, followed by a complete an aggressive combination of radiation and chemotherapy and/or palliative care. Despite best efforts, 1-year overall survival of patients is 20% to 40% with nearly universal mortality rate. Consequently, novel approaches (targeted therapy, immunotherapy) have been studied, alone or in combination, to improve the dire prognosis of these patients. BRAF V600E mutation is the most common genetic mutation found in ATC. We report the case of a 57-year-old man diagnosed with stage IVc (undifferentiated) ATC with hepatic and osseous metastases. The molecular analysis of the tumor revealed a V600E BRAF-mutation. The patient was treated with Dabrafenib and Trametinib, and achieved remission 5 weeks after starting the treatment. Subsequently, he had a thyroidectomy, and pembrolizumab was added to the two tyrosine kinase inhibitors. 9 months later he is still in remission. This case illustrates the importance of obtaining molecular information in anaplastic thyroid cancer and the urgent need of studies investigating the combination of tyrosine kinase inhibitors and check-point inhibitors in patients with V600E BRAF- mutations.

Occurrence of diverse aminoglycoside modifying enzymes with co-existing extended-spectrum-β-lactamases within Enterobacteriaceae isolated in India

OBJECTIVE

The present study describes aminoglycoside modifying enzymes (AMEs) among clinical isolates with coexisting extended spectrum beta-lactamases.

METHODOLOGY

A total of 227 non duplicate enterobacterial isolates were collected and identified from patients who were admitted to different wards or attended OPD of a tertiary referral hospital of North-East India. Isolates were initially screened for antimicrobial susceptibility testing followed by PCR based screening of aminoglycosides modifying enzymes and co-existing ESBLs and carbapenemases. Horizontal transferability, incompatibility typing and stability of plasmids were also analyzed.

RESULTS

Diverse types of AMEs were observed namely; ant(3″)-I, ant(4')-Ia, aac(3)-IIc, ant(3')-I, aac(6')-Ib, ant(2″)-Ia and aac(6'). Majority of the AME positive isolates harboured bla_TEM followed by bla_CTX-M-15 and a combination of bla_TEM and bla_CTX-M-15 were also observed. Nine isolates were found to harbour carbapenemases genes. AME genes were found to be located within a self conjugative plasmid of Inc FIA, IncY, IncN, IncFIB and IncA/C incompatibility types. It was observed that most AME genes were stable over 50 days of serial passages whereas aph(3')-Via and aph(3')-IIb were completely lost within 50 days.

CONCLUSION

This study underscores the co-existence of AMEs and ESBLs within enterobacteriaceae which emphasize a reassessment of combination therapy in the health settings.

Adaptation of blaNDMthrough IncP plasmid within broad host range

Introduction

It was also known that the IncP-1 plasmids are ubiquitous in environmental bacteria and those reside in soil, sewage, marine sediments and in manure. The blaNDMis associated with resistance determinants along with various mobile elements such as plasmid, insertion sequences and transposons, which facilitates its horizontal dissemination. These plasmids, if tracked, can be a starting point for the control of infection due to multidrug-resistant pathogens. The aim of the study was to investigate that IncP-type plasmids carrying blaNDMis adapted in different hosts.

Materials and Methods

Thirteen of the isolates were harbouring IncP-type plasmid and they all were Escherichia coli isolated from hospitalised patients of Silchar Medical College and Hospital, India. The isolates were checked for susceptibility test, and the stability was assessed by a serial passage. These isolates were further subjected to transcriptional analysis of NDM gene as well as plasmid copy number alteration.

Results

The study isolates were highly stable, and the resistance gene (blaNDM) was retained within isolates till 55th subsequent serial passages. Plasmid copy number alteration was random in isolates when exposed to carbapenem antibiotics, whereas increasing trend in transcriptional expression was observed with the increase in imipenem concentration.

Conclusion

This study was able to underscore the presence of IncP plasmid that was harbouring blaNDMand was maintained within diverse host. The finding also highlights the adaptation of the broad-host-range plasmid that responds in terms of transcriptional expression under antibiotic exposure.

An insight into analysis and elimination of plasmids encoding metallo-β-lactamases in Pseudomonas aeruginosa

OBJECTIVES

The aim of this study was to characterise metallo-β-lactamase (MBL)-harbouring plasmids, their change in copy number in respect to different antibiotic pressure, and the efficiency of different curing agents in eliminating these resistance plasmids from nosocomial Pseudomonas aeruginosa isolates.

METHODS

Plasmids were extracted from four isolates harbouring bla_NDM-1 or bla_VIM-2 under four different concentrations of imipenem, meropenem, ertapenem, aztreonam and cefotaxime. Quantitative real-time PCR was performed to analyse the change in plasmid copy number under these different conditions. The effect of different physical and chemical curing agents in elimination of plasmids carrying bla_NDM-1 and bla_VIM-2 was examined, with meropenem resistance used as a selectable marker.

RESULTS

Conjugatively transferable MBL genes (bla_NDM-1 and bla_VIM-2) carried on plasmids were found to be highly stable. Sodium dodecyl sulfate (SDS) was the most effective agent in eliminating these resistance plasmids. The change in copy number of the bla_NDM-1-encoding plasmid was found to be similar to the bla_VIM-2-encoding plasmid, with a single exception under cefotaxime pressure.

CONCLUSION

The spread of multidrug resistance plasmids has been noted as a key factor associated with increasing carbapenem resistance. Successful curing of resistance plasmids can reverse the bacterial phenotype back to susceptible. This study revealed that different antibiotic pressure induces a change in copy number of MBL-encoding plasmids. SDS can be successfully used as an eliminating agent for these resistance determinants, although therapeutic application of this agent is not possible due to its high toxicity and mutagenic nature.

AcrAB-TolC efflux pump system plays a role in carbapenem non-susceptibility in Escherichia coli

Background

Efflux pump mediated antibiotic resistance is an unnoticed and undetected mechanism in clinical microbiology laboratory. RND efflux systems are known for aminoglycoside and tetracycline resistance whereas their role in carbapenem non-susceptibility is not established. The study was undertaken to investigate the role of efflux pump in providing resistance against carbapenems and their response against concentration gradient carbapenem stress on the transcriptional level of the AcrAB gene in the clinical isolates of Escherichia coli from a tertiary referral hospital of Northeast India.

Results

Out of 298 non-susceptible Escherichia coli isolates 98 isolates were found to have efflux pump mediated carbapenem non-susceptibility. Among them thirty-five were non carbapenemase producers and their expressional levels were verified using qRT-PCR under concentration gradient carbapenem stress. In this study, a strong correlation between ertapenem resistance and AcrA overexpression was observed which has not been reported previously. Further, it was observed that imipenem stress increased AcrB expression in Escherichia coli which holds the novelty of this study. Additionally, the transcription of AcrR was insistently increased which is much higher than the transcriptional level of AcrA under concentration gradient carbapenem stress condition.

Conclusion

The study established that AcrAB pump is a relevant antibiotic resistance determinant in bacterial pathogen, has an important role in developing resistance against carbapenem group of antibiotics.

Electronic supplementary material

The online version of this article (10.1186/s12866-019-1589-1) contains supplementary material, which is available to authorized users.

Prevention and reversal of Type 2 diabetes: highlights from a symposium at the 2019 Diabetes UK Annual Professional Conference

AIM

This symposium covers the gamut of Type 2 diabetes prevention, reversing established Type 2 diabetes, population-level delivery of weight loss programmes and personal insights into achieving and retaining substantial weight loss.

RESULTS

The NHS Diabetes Prevention Programme was launched in 2016 and rates of referral and attendance have both exceeded expectations. By March 2018, mean weight loss for completers (those attending more than 60% of sessions) was 3.2 kg reflecting considerable health benefits. Established Type 2 diabetes is now known to be a reversible condition in the early years, and the underlying mechanism is the removal of the excess fat from within liver and pancreas in these susceptible individuals. The Diabetes Remission Clinical Trial has shown that around half of a primary care population of people with Type 2 diabetes of less than 6 years' duration can be returned to non-diabetic blood glucose control which lasts at least 12 months. This raises the question of population-level intervention to achieve weight loss. The success of some mass weight loss programmes requires to be recognized. Reframing mass provision of weight loss support should be a vital part of our clinical strategy to prevent and treat Type 2 diabetes. However, the current obesogenic environment is a reality in which individuals must live. A personal account of achieving substantial and maintaining substantial weight loss provides an invaluable insight into practical problems encountered. All health professionals dealing with weight control should assimilate and reflect upon this understanding.

CONCLUSIONS

Effective prevention and long term reversal of Type 2 diabetes is feasible. The impact upon the individual must be considered during delivery of advice and support.

PREVALENCE OF GESTATIONAL DIABETES MELLITUS IN AN URBAN INDIAN COHORT USING DIABETES IN PREGNANCY STUDY GROUP IN INDIA (DIPSI) CRITERIA – VALIDATING ONE-STEP APPROACH

Background. India is the “World’s Diabetes capital”, with half the diabetic population being women. Early detection of glucose intolerance during pregnancy offers a timely opportunity for screening, management and prevention of gestational diabetes mellitus (GDM) and prevents fetal complications. Objective. The study assessed the prevalence of GDM in an Indian cohort using the Diabetes in Pregnancy Study group of India (DIPSI) criteria. Methods. 200 pregnant women underwent two-phase testing with non-fasting 75-gram glucose challenge under Diabetes in Pregnancy Study group of India (DIPSI) criteria at <20 weeks and between 24-28 weeks period of gestation. A 3-hour 100-gm oral glucose tolerance test (OGTT) was used for confirmation. Repeat testing was done for women negative during the first-phase. Results. Mean age was 24.26±3.75 years with 52.5% multigravidas. Mean Body Mass Index (BMI) was 20.7±3.07 kg/m2. The prevalence of GDM in study cohort was found to be 15.5% using the DIPSI criteria while the prevalence of GDM after 100 g OGTT was 13.0%. GDM was mostly seen to occur in women of 26-30-year age group. Statistically significant associations for age and GDM, and BMI and GDM were evidenced. Conclusions. Maternal age of ≥25 years should be adopted as a risk factor for the development of GDM. The DIPSI criteria offer a cost-effective and an evidence-based protocol for a single-step definitive glucose test for both screening and diagnosis of pregnant patients belonging to any socio-economic strata; furthering its implementation for public health obstetrics.

Observation of a new pattern of mutations in gyrA and parC within Escherichia coli exhibiting fluroquinolone resistance

Therapeutic options with quinolones are severely compromised in infections caused by members of Enterobacteriaceae family. Mutations in chromosomal region are one of the major reasons for bacterial resistance towards this group of antibiotic. The aim of the study is to detect the mutations in gyr A and par C responsible for quinolone resistance among clinical isolates of Escherichia coli. A total of 96 quinolone-resistant clinical isolates of E. coli were collected from a tertiary care hospital of North-east India during March 2015 to August 2015. All the quinolone-resistant E. coli strains were investigated for mutations in the topoisomerases genes gyrA and parC by amplifying and sequencing the quinolone resistance determining regions. Among the 96 E. coli isolates, 83.3% were resistant to nalidixic acid and 80.2%, 66.6%, 23.9% and 50% to ciprofloxacin, norfloxacin, levofloxacin and ofloxacin, respectively. Several alterations were detected in gyrA and parC genes. Three new patterns of amino acid substitution are reported in E. coli isolates. The findings of this study warrant a review in quinolone-based therapy in this region of the world to stop or slow down the irrational use this drug.