Asish K. Mukhopadhyay

AN EFFICIENT METHOD OF MOBILE IP BASED HANDOFF MECHANISM FOR WLAN-GPRS INTEGRATED NETWORK (2007)

Sibaram Khara,, Asish K. Mukhopadhyay

This paper proposes a new technique for Mobile IP (MIP) registration by WLAN host (WH) of the Internet through GPRS network. The home agent (HA) of WH resides in the Internet. The gateway GPRS...

Virulence Genes in Environmental Strains of Vibrio cholerae

Chakraborty, Soumen, Mukhopadhyay, Asish K., Bhadra, Rupak Kumar, Ghosh, Amar Nath, Mitra, Rupak, Shimada, Toshio, ...

The virulence of a pathogen is dependent on a discrete set of genetic determinants and their well-regulated expression. The ctxAB and tcpA genes are known to play a cardinal role in maintaining...

Differences in Genotypes of Helicobacter pylori from Different Human Populations

Kersulyte, Dangeruta, Mukhopadhyay, Asish K., Velapatiño, Billie, Su, WanWen, Pan, ZhiJun, Garcia, Claudia, ...

DNA motifs at several informative loci in more than 500 strains of Helicobacter pylori from five continents were studied by PCR and sequencing to gain insights into the evolution of this gastric...

Distinctiveness of Genotypes of Helicobacter pylori in Calcutta, India

Mukhopadhyay, Asish K., Kersulyte, Dangeruta, Jeong, Jin-Yong, Datta, Simanti, Ito, Yoshiyuki, Chowdhury, Abhijit, ...

The genotypes of 78 strains of Helicobacter pylori from Calcutta, India (55 from ulcer patients and 23 from more-benign infections), were studied, with a focus on putative virulence genes and neutral...

Sequential Inactivation of rdxA (HP0954) and frxA (HP0642) Nitroreductase Genes Causes Moderate and High-Level Metronidazole Resistance in Helicobacter pylori

Jeong, Jin-Yong, Mukhopadhyay, Asish K., Dailidiene, Daiva, Wang, Yipeng, Velapatiño, Billie, Gilman, Robert H., ...

Helicobacter pylori is a human-pathogenic bacterial species that is subdivided geographically, with different genotypes predominating in different parts of the world. Here we test and extend an...

Roles of FrxA and RdxA Nitroreductases of Helicobacter pylori in Susceptibility and Resistance to Metronidazole

Jeong, Jin-Yong, Mukhopadhyay, Asish K., Akada, Junko K., Dailidiene, Daiva, Hoffman, Paul S., Berg, Douglas E.

The relative importance of the frxA and rdxA nitroreductase genes of Helicobacter pylori in metronidazole (MTZ) susceptibility and resistance has been controversial. Jeong et al. (J. Bacteriol....

Cell Vacuolation, a Manifestation of the El Tor Hemolysin of Vibrio cholerae

Mitra, Rupak, Figueroa, Paula, Mukhopadhyay, Asish K., Shimada, Toshio, Takeda, Yoshifumi, Berg, Douglas E., ...

Culture supernatants of nontoxigenic nonepidemic clinical strains of Vibrio cholerae belonging to diverse serogroups were found to induce vacuolation of nonconfluent HeLa cells. The vacuoles became...

Characterization of VPI Pathogenicity Island and CTXφ Prophage in Environmental Strains of Vibrio cholerae

Mukhopadhyay, Asish K., Chakraborty, Soumen, Takeda, Yoshifumi, Nair, G. Balakrish, Berg, Douglas E.

Environmental isolates of Vibrio cholerae of eight randomly amplified polymorphic DNA (RAPD) fingerprint types from Calcutta, India, that were unusual in containing toxin-coregulated pilus or cholera...

Molecular Analysis of Non-O1, Non-O139 Vibrio cholerae Associated with an Unusual Upsurge in the Incidence of Cholera-Like Disease in Calcutta, India

Sharma, Charu, Thungapathra, M., Ghosh, A., Mukhopadhyay, Asish K., Basu, Arnab, Mitra, Rupak, ...

There was an inexplicable upsurge in the incidence of non-O1, non-O139 Vibrio cholerae among hospitalized patients admitted to the Infectious Diseases Hospital, Calcutta, India, between February and...

Functional Organization and Insertion Specificity of IS607, a Chimeric Element of Helicobacter pylori

Kersulyte, Dangeruta, Mukhopadhyay, Asish K., Shirai, Mutsinori, Nakazawa, Teruko, Berg, Douglas E.

A search by subtractive hybridization for sequences present in only certain strains of Helicobacter pylori led to the discovery of a 2-kb transposable element to be called IS607, which further PCR...

Virulence Genes in Helicobacter pylori Strains from West Bengal Residents with Overt H. pylori-Associated Disease and Healthy Volunteers

Chattopadhyay, Santanu, Datta, Simanti, Chowdhury, Abhijit, Chowdhury, Sujit, Mukhopadhyay, Asish K., Rajendran, K., ...

We compared putative molecular markers of virulence (vacA, cagA, and iceA) of Helicobacter pylori strains isolated from 52 adult duodenal ulcer patients from West Bengal, India, with those of H....

Enzymes Associated with Reductive Activation and Action of Nitazoxanide, Nitrofurans, and Metronidazole in Helicobacter pylori

Sisson, Gary, Goodwin, Avery, Raudonikiene, Ausra, Hughes, Nicky J., Mukhopadhyay, Asish K., Berg, Douglas E., ...

Nitazoxanide (NTZ) is a redox-active nitrothiazolyl-salicylamide prodrug that kills Helicobacter pylori and also many anaerobic bacterial, protozoan, and helminthic species. Here we describe...

Emergence of Tetracycline Resistance in Helicobacter pylori: Multiple Mutational Changes in 16S Ribosomal DNA and Other Genetic Loci

Dailidiene, Daiva, Bertoli, M. Teresita, Miciuleviciene, Jolanta, Mukhopadhyay, Asish K., Dailide, Giedrius, Pascasio, Mario Alberto, ...

Tetracycline is useful in combination therapies against the gastric pathogen Helicobacter pylori. We found 6 tetracycline-resistant (Tetr) strains among 159 clinical isolates (from El Salvador,...

Transposable Element ISHp608 of Helicobacter pylori: Nonrandom Geographic Distribution, Functional Organization, and Insertion Specificity

Kersulyte, Dangeruta, Velapatiño, Billie, Dailide, Giedrius, Mukhopadhyay, Asish K., Ito, Yoshiyuki, Cahuayme, Lizbeth, ...

A new member of the IS605 transposable element family, designated ISHp608, was found by subtractive hybridization in Helicobacter pylori. Like the three other insertion sequences (ISs) known in this...

The fdxA Ferredoxin Gene Can Down-Regulate frxA Nitroreductase Gene Expression and Is Essential in Many Strains of Helicobacter pylori

Mukhopadhyay, Asish K., Jeong, Jin-Yong, Dailidiene, Daiva, Hoffman, Paul S., Berg, Douglas E.

Very few examples of metabolic regulation are known in the gastric pathogen Helicobacter pylori. An unanticipated case was suggested, however, upon finding two types of metronidazole...

DNA-Level Characterization of Helicobacter pylori Strains from Patients with Overt Disease and with Benign Infections in Bangladesh

Rahman, Motiur, Mukhopadhyay, Asish K., Nahar, Shamsun, Datta, Simanti, Mashhud Ahmad, Milan, Sarker, Safique, ...

The complex relation between the genotype of Helicobacter pylori and its association with clinical outcome is not well understood. Studies in the West have showed that strains expressing certain...

Cluster of Type IV Secretion Genes in Helicobacter pylori's Plasticity Zone

Kersulyte, Dangeruta, Velapatiño, Billie, Mukhopadhyay, Asish K., Cahuayme, Lizbeth, Bussalleu, Alejandro, Combe, Juan, ...

Some genes present in only certain strains of the genetically diverse gastric pathogen Helicobacter pylori may affect its phenotype and/or evolutionary potential. Here we describe a new 16.3-kb...

Virulence Genes and Neutral DNA Markers of Helicobacter pylori Isolates from Different Ethnic Communities of West Bengal, India

Datta, Simanti, Chattopadhyay, Santanu, Balakrish Nair, G., Mukhopadhyay, Asish K., Hembram, Jabaranjan, Berg, Douglas E., ...

Virulence-associated genes and neutral DNA markers of Helicobacter pylori strains from the Santhal and Oroan ethnic minorities of West Bengal, India, were studied. These people have traditionally...

Helicobacter acinonychis: Genetic and Rodent Infection Studies of a Helicobacter pylori-Like Gastric Pathogen of Cheetahs and Other Big Cats

Dailidiene, Daiva, Dailide, Giedrius, Ogura, Keiji, Zhang, Maojun, Mukhopadhyay, Asish K., Eaton, Kathryn A., ...

Insights into bacterium-host interactions and genome evolution can emerge from comparisons among related species. Here we studied Helicobacter acinonychis (formerly H. acinonyx), a species closely...

Multiplex PCR Assay for Rapid Detection and Genotyping of Helicobacter pylori Directly from Biopsy Specimens

Chattopadhyay, Santanu, Patra, Rajashree, Ramamurthy, T., Chowdhury, Abhijit, Santra, Amal, Dhali, G. K., ...

We developed and evaluated a simple, novel multiplex PCR assay for rapid detection of Helicobacter pylori infection and for the determination of vacA and cagA genotypes directly from gastric biopsy...

Antimicrobial Susceptibility of Helicobacter pylori Strains Isolated in Bangladesh

Nahar, Shamsun, Mukhopadhyay, Asish K., Khan, Rasel, Ahmad, Mian Mashhud, Datta, Simanti, Chattopadhyay, Santanu, ...

Antimicrobial susceptibility of 120 Helicobacter pylori isolates to metronidazole, tetracycline, clarithromycin, and amoxicillin was determined, and 77.5, 15, 10, and 6.6% of the isolates,...

Evolutionary Dynamics of Insertion Sequences in Helicobacter pylori

Kalia, Awdhesh, Mukhopadhyay, Asish K., Dailide, Giedrius, Ito, Yoshiyki, Azuma, Takeshi, Wong, Benjamin C. Y., ...

Prokaryotic insertion sequence (IS) elements behave like parasites in terms of their ability to invade and proliferate in microbial gene pools and like symbionts when they coevolve with their...

Mechanism of Drug Resistance in Clonally Related Clinical Isolates of Vibrio fluvialis Isolated in Kolkata, India

Srinivasan, Vijaya Bharathi, Virk, Rupinder Kaur, Kaundal, Amita, Chakraborty, Rupa, Datta, Basabjit, Ramamurthy, T., ...

The molecular mechanisms of drug resistance in 19 strains of Vibrio fluvialis isolated from 1998 to 2002 in Kolkata, India, were investigated. Class 1 integrons were detected in eight strains, and...

Virulence Genes in Environmental Strains of Vibrio cholerae

Chakraborty, Soumen, Mukhopadhyay, Asish K., Bhadra, Rupak Kumar, Ghosh, Amar Nath, Mitra, Rupak, Shimada, Toshio, ...

The virulence of a pathogen is dependent on a discrete set of genetic determinants and their well-regulated expression. The ctxAB and tcpA genes are known to play a cardinal role in maintaining...

Differences in Genotypes of Helicobacter pylori from Different Human Populations

Kersulyte, Dangeruta, Mukhopadhyay, Asish K., Velapatiño, Billie, Su, WanWen, Pan, ZhiJun, Garcia, Claudia, ...

DNA motifs at several informative loci in more than 500 strains of Helicobacter pylori from five continents were studied by PCR and sequencing to gain insights into the evolution of this gastric...

Distinctiveness of Genotypes of Helicobacter pylori in Calcutta, India

Mukhopadhyay, Asish K., Kersulyte, Dangeruta, Jeong, Jin-Yong, Datta, Simanti, Ito, Yoshiyuki, Chowdhury, Abhijit, ...

The genotypes of 78 strains of Helicobacter pylori from Calcutta, India (55 from ulcer patients and 23 from more-benign infections), were studied, with a focus on putative virulence genes and neutral...

Sequential Inactivation of rdxA (HP0954) and frxA (HP0642) Nitroreductase Genes Causes Moderate and High-Level Metronidazole Resistance in Helicobacter pylori

Jeong, Jin-Yong, Mukhopadhyay, Asish K., Dailidiene, Daiva, Wang, Yipeng, Velapatiño, Billie, Gilman, Robert H., ...

Helicobacter pylori is a human-pathogenic bacterial species that is subdivided geographically, with different genotypes predominating in different parts of the world. Here we test and extend an...

Roles of FrxA and RdxA Nitroreductases of Helicobacter pylori in Susceptibility and Resistance to Metronidazole

Jeong, Jin-Yong, Mukhopadhyay, Asish K., Akada, Junko K., Dailidiene, Daiva, Hoffman, Paul S., Berg, Douglas E.

The relative importance of the frxA and rdxA nitroreductase genes of Helicobacter pylori in metronidazole (MTZ) susceptibility and resistance has been controversial. Jeong et al. (J. Bacteriol....

Cell Vacuolation, a Manifestation of the El Tor Hemolysin of Vibrio cholerae

Mitra, Rupak, Figueroa, Paula, Mukhopadhyay, Asish K., Shimada, Toshio, Takeda, Yoshifumi, Berg, Douglas E., ...

Culture supernatants of nontoxigenic nonepidemic clinical strains of Vibrio cholerae belonging to diverse serogroups were found to induce vacuolation of nonconfluent HeLa cells. The vacuoles became...

Characterization of VPI Pathogenicity Island and CTXφ Prophage in Environmental Strains of Vibrio cholerae

Mukhopadhyay, Asish K., Chakraborty, Soumen, Takeda, Yoshifumi, Nair, G. Balakrish, Berg, Douglas E.

Environmental isolates of Vibrio cholerae of eight randomly amplified polymorphic DNA (RAPD) fingerprint types from Calcutta, India, that were unusual in containing toxin-coregulated pilus or cholera...

Molecular Analysis of Non-O1, Non-O139 Vibrio cholerae Associated with an Unusual Upsurge in the Incidence of Cholera-Like Disease in Calcutta, India

Sharma, Charu, Thungapathra, M., Ghosh, A., Mukhopadhyay, Asish K., Basu, Arnab, Mitra, Rupak, ...

There was an inexplicable upsurge in the incidence of non-O1, non-O139 Vibrio cholerae among hospitalized patients admitted to the Infectious Diseases Hospital, Calcutta, India, between February and...

Functional Organization and Insertion Specificity of IS607, a Chimeric Element of Helicobacter pylori

Kersulyte, Dangeruta, Mukhopadhyay, Asish K., Shirai, Mutsinori, Nakazawa, Teruko, Berg, Douglas E.

A search by subtractive hybridization for sequences present in only certain strains of Helicobacter pylori led to the discovery of a 2-kb transposable element to be called IS607, which further PCR...

Virulence Genes in Helicobacter pylori Strains from West Bengal Residents with Overt H. pylori-Associated Disease and Healthy Volunteers

Chattopadhyay, Santanu, Datta, Simanti, Chowdhury, Abhijit, Chowdhury, Sujit, Mukhopadhyay, Asish K., Rajendran, K., ...

We compared putative molecular markers of virulence (vacA, cagA, and iceA) of Helicobacter pylori strains isolated from 52 adult duodenal ulcer patients from West Bengal, India, with those of H....

Enzymes Associated with Reductive Activation and Action of Nitazoxanide, Nitrofurans, and Metronidazole in Helicobacter pylori

Sisson, Gary, Goodwin, Avery, Raudonikiene, Ausra, Hughes, Nicky J., Mukhopadhyay, Asish K., Berg, Douglas E., ...

Nitazoxanide (NTZ) is a redox-active nitrothiazolyl-salicylamide prodrug that kills Helicobacter pylori and also many anaerobic bacterial, protozoan, and helminthic species. Here we describe...

Emergence of Tetracycline Resistance in Helicobacter pylori: Multiple Mutational Changes in 16S Ribosomal DNA and Other Genetic Loci

Dailidiene, Daiva, Bertoli, M. Teresita, Miciuleviciene, Jolanta, Mukhopadhyay, Asish K., Dailide, Giedrius, Pascasio, Mario Alberto, ...

Tetracycline is useful in combination therapies against the gastric pathogen Helicobacter pylori. We found 6 tetracycline-resistant (Tetr) strains among 159 clinical isolates (from El Salvador,...

Transposable Element ISHp608 of Helicobacter pylori: Nonrandom Geographic Distribution, Functional Organization, and Insertion Specificity

Kersulyte, Dangeruta, Velapatiño, Billie, Dailide, Giedrius, Mukhopadhyay, Asish K., Ito, Yoshiyuki, Cahuayme, Lizbeth, ...

A new member of the IS605 transposable element family, designated ISHp608, was found by subtractive hybridization in Helicobacter pylori. Like the three other insertion sequences (ISs) known in this...

The fdxA Ferredoxin Gene Can Down-Regulate frxA Nitroreductase Gene Expression and Is Essential in Many Strains of Helicobacter pylori

Mukhopadhyay, Asish K., Jeong, Jin-Yong, Dailidiene, Daiva, Hoffman, Paul S., Berg, Douglas E.

Very few examples of metabolic regulation are known in the gastric pathogen Helicobacter pylori. An unanticipated case was suggested, however, upon finding two types of metronidazole...

DNA-Level Characterization of Helicobacter pylori Strains from Patients with Overt Disease and with Benign Infections in Bangladesh

Rahman, Motiur, Mukhopadhyay, Asish K., Nahar, Shamsun, Datta, Simanti, Mashhud Ahmad, Milan, Sarker, Safique, ...

The complex relation between the genotype of Helicobacter pylori and its association with clinical outcome is not well understood. Studies in the West have showed that strains expressing certain...

Cluster of Type IV Secretion Genes in Helicobacter pylori's Plasticity Zone

Kersulyte, Dangeruta, Velapatiño, Billie, Mukhopadhyay, Asish K., Cahuayme, Lizbeth, Bussalleu, Alejandro, Combe, Juan, ...

Some genes present in only certain strains of the genetically diverse gastric pathogen Helicobacter pylori may affect its phenotype and/or evolutionary potential. Here we describe a new 16.3-kb...

Virulence Genes and Neutral DNA Markers of Helicobacter pylori Isolates from Different Ethnic Communities of West Bengal, India

Datta, Simanti, Chattopadhyay, Santanu, Balakrish Nair, G., Mukhopadhyay, Asish K., Hembram, Jabaranjan, Berg, Douglas E., ...

Virulence-associated genes and neutral DNA markers of Helicobacter pylori strains from the Santhal and Oroan ethnic minorities of West Bengal, India, were studied. These people have traditionally...

Helicobacter acinonychis: Genetic and Rodent Infection Studies of a Helicobacter pylori-Like Gastric Pathogen of Cheetahs and Other Big Cats

Dailidiene, Daiva, Dailide, Giedrius, Ogura, Keiji, Zhang, Maojun, Mukhopadhyay, Asish K., Eaton, Kathryn A., ...

Insights into bacterium-host interactions and genome evolution can emerge from comparisons among related species. Here we studied Helicobacter acinonychis (formerly H. acinonyx), a species closely...

Multiplex PCR Assay for Rapid Detection and Genotyping of Helicobacter pylori Directly from Biopsy Specimens

Chattopadhyay, Santanu, Patra, Rajashree, Ramamurthy, T., Chowdhury, Abhijit, Santra, Amal, Dhali, G. K., ...

We developed and evaluated a simple, novel multiplex PCR assay for rapid detection of Helicobacter pylori infection and for the determination of vacA and cagA genotypes directly from gastric biopsy...

Antimicrobial Susceptibility of Helicobacter pylori Strains Isolated in Bangladesh

Nahar, Shamsun, Mukhopadhyay, Asish K., Khan, Rasel, Ahmad, Mian Mashhud, Datta, Simanti, Chattopadhyay, Santanu, ...

Antimicrobial susceptibility of 120 Helicobacter pylori isolates to metronidazole, tetracycline, clarithromycin, and amoxicillin was determined, and 77.5, 15, 10, and 6.6% of the isolates,...

Evolutionary Dynamics of Insertion Sequences in Helicobacter pylori

Kalia, Awdhesh, Mukhopadhyay, Asish K., Dailide, Giedrius, Ito, Yoshiyki, Azuma, Takeshi, Wong, Benjamin C. Y., ...

Prokaryotic insertion sequence (IS) elements behave like parasites in terms of their ability to invade and proliferate in microbial gene pools and like symbionts when they coevolve with their...

Mechanism of Drug Resistance in Clonally Related Clinical Isolates of Vibrio fluvialis Isolated in Kolkata, India

Srinivasan, Vijaya Bharathi, Virk, Rupinder Kaur, Kaundal, Amita, Chakraborty, Rupa, Datta, Basabjit, Ramamurthy, T., ...

The molecular mechanisms of drug resistance in 19 strains of Vibrio fluvialis isolated from 1998 to 2002 in Kolkata, India, were investigated. Class 1 integrons were detected in eight strains, and...