Nicholas P. J. Day

Recombination within natural populations of pathogenic bacteria: Short-term empirical estimates and long-term phylogenetic consequences

Feil, Edward J., Holmes, Edward C., Bessen, Debra E., Chan, Man-Suen, Day, Nicholas P. J., Enright, Mark C., ...

The identification of clones within bacterial populations is often taken as evidence for a low rate of recombination, but the validity of this inference is rarely examined. We have used statistical...

Epidemic Typhoid in Vietnam: Molecular Typing of Multiple-Antibiotic-Resistant Salmonella enterica Serotype Typhi from Four Outbreaks

Connerton, Phillippa, Wain, John, Hien, Tran T., Ali, Tahir, Parry, Christopher, Chinh, Nguyen T., ...

Multidrug-resistant Salmonella enterica serotype Typhi isolates from four outbreaks of typhoid fever in southern Vietnam between 1993 and 1997 were compared. Pulsed-field gel electrophoresis,...

Multilocus Sequence Typing for Characterization of Methicillin-Resistant and Methicillin-Susceptible Clones of Staphylococcus aureus

Enright, Mark C., Day, Nicholas P. J., Davies, Catrin E., Peacock, Sharon J., Spratt, Brian G.

A multilocus sequence typing (MLST) scheme has been developed for Staphylococcus aureus. The sequences of internal fragments of seven housekeeping genes were obtained for 155 S. aureus isolates from...

Quantitation of Bacteria in Bone Marrow from Patients with Typhoid Fever: Relationship between Counts and Clinical Features

Wain, John, Bay, Phan Van Be, Vinh, Ha, Duong, Nguyen M., Diep, To Song, Walsh, Amanda L., ...

Enteric fever is the only bacterial infection of humans for which bone marrow examination is routinely recommended. A prospective study of the concentrations of bacteria in the bone marrow and their...

Virulent Combinations of Adhesin and Toxin Genes in Natural Populations of Staphylococcus aureus

Peacock, Sharon J., Moore, Catrin E., Justice, Anita, Kantzanou, Maria, Story, Lisa, Mackie, Kathryn, ...

Most cases of severe Staphylococcus aureus disease cannot be explained by the action of a single virulence determinant, and it is likely that a number of factors act in combination during the...

Emergence in Vietnam of Streptococcus pneumoniae Resistant to Multiple Antimicrobial Agents as a Result of Dissemination of the Multiresistant Spain23F-1 Clone

Parry, Christopher M., Duong, Nguyen Minh, Zhou, Jiaji, Mai, Nguyen Thi Hoang, Diep, To Song, Thinh, Le Quoc, ...

Surveillance for Streptococcus pneumoniae resistant to penicillin and other antimicrobial agents is necessary to define the optimal empirical antibiotic therapy for meningitis in resource-poor...

Determinants of Acquisition and Carriage of Staphylococcus aureus in Infancy

Peacock, Sharon J., Justice, Anita, Griffiths, D., Kantzanou, M. N., Crook, Derrick, ...

Nasal carriage of Staphylococcus aureus is a major risk factor for invasive S. aureus disease. The aim of this study was to define factors associated with carriage. We conducted a prospective,...

Complete genomes of two clinical Staphylococcus aureus strains: Evidence for the rapid evolution of virulence and drug resistance

Holden, Matthew T. G., Feil, Edward J., Lindsay, Jodi A., Peacock, Sharon J., Day, Nicholas P. J., Enright, Mark C., ...

Staphylococcus aureus is an important nosocomial and community-acquired pathogen. Its genetic plasticity has facilitated the evolution of many virulent and drug-resistant strains, presenting a major...

Evaluation of Immunoglobulin M (IgM) and IgG Rapid Cassette Test Kits for Diagnosis of Melioidosis in an Area of Endemicity

Wuthiekanun, Vanaporn, Amornchai, Premjit, Chierakul, Wirongrong, Cheng, Allen C., White, Nicholas J., Peacock, Sharon J., ...

An enzyme-linked immunosorbent assay-based rapid cassette immunoglobulin G (IgG) and IgM immunochromogenic test kit was compared to the indirect hemagglutination test (IHA) for the diagnosis of acute...

Lack of Association between Toll-Like Receptor 2 Polymorphisms and Susceptibility to Severe Disease Caused by Staphylococcus aureus

Moore, Catrin E., Segal, Shelley, Berendt, Anthony R., Hill, Adrian V. S., Day, Nicholas P. J.

To investigate a putative link between genetically determined variations in Toll-like receptor 2 (TLR2) and the occurrence of severe Staphylococcus aureus infection, the functional Arg753Gln...

In Vivo Assessment of Drug Efficacy against Plasmodium falciparum Malaria: Duration of Follow-Up

Stepniewska, Kasia, Taylor, Walter R.J., Mayxay, Mayfong, Price, Ric, Smithuis, Frank, Guthmann, Jean-Paul, ...

To determine the optimum duration of follow-up for the assessment of drug efficacy against Plasmodium falciparum malaria, 96 trial arms from randomized controlled trials (RCTs) with follow-up of 28...

Detection of Burkholderia pseudomallei in Soil within the Lao People's Democratic Republic

Wuthiekanun, Vanaporn, Mayxay, Mayfong, Chierakul, Wirongrong, Phetsouvanh, Rattanaphone, Cheng, Allen C., White, Nicholas J, ...

Clinical cases of melioidosis caused by the saprophyte Burkholderia pseudomallei were first noted in the Lao People's Democratic Republic (PDR) in 1999. In this study, 36% of 110 soil samples in...

Rapid Immunofluorescence Microscopy for Diagnosis of Melioidosis

Wuthiekanun, Vanaporn, Desakorn, Varunee, Wongsuvan, Gumphol, Amornchai, Premjit, Cheng, Allen C., Maharjan, Bina, ...

An immunofluorescent (IF) method that detects Burkholderia pseudomallei in clinical specimens within 10 min was devised. The results of this rapid method and those of an existing IF method were...

Role and Significance of Quantitative Urine Cultures in Diagnosis of Melioidosis

Limmathurotsakul, Direk, Wuthiekanun, Vanaporn, Chierakul, Wirongrong, Cheng, Allen C., Maharjan, Bina, Chaowagul, Wipada, ...

Melioidosis is associated with significant mortality in countries in which it is endemic. Previous studies have demonstrated that quantitative Burkholderia pseudomallei counts in blood are predictive...

Estimation of the Total Parasite Biomass in Acute Falciparum Malaria from Plasma PfHRP2

Dondorp, Arjen M, Desakorn, Varunee, Pongtavornpinyo, Wirichada, Sahassananda, Duangjai, Silamut, Kamolrat, Chotivanich, Kesinee, ...

Measuring sequestered parasites using plasma PfHRP2 concentrations may provide a more accurate estimate of total parasite mass and hence severity in falciparum malaria.

Antibodies from Patients with Melioidosis Recognize Burkholderia mallei but Not Burkholderia thailandensis Antigens in the Indirect Hemagglutination Assay

Tiyawisutsri, Rachaneeporn, Peacock, Sharon J., Langa, Sayan, Limmathurotsakul, Direk, Cheng, Allen C., Chierakul, Wirongrong, ...

The indirect hemagglutination assay routinely used to detect antibodies to Burkholderia pseudomallei was modified to detect cross-reactivity of antibodies to B. pseudomallei, B. mallei, and B....

Comparison of Ashdown's Medium, Burkholderia cepacia Medium, and Burkholderia pseudomallei Selective Agar for Clinical Isolation of Burkholderia pseudomallei

Peacock, Sharon J., Chieng, Grace, Cheng, Allen C., Dance, David A. B., Amornchai, Premjit, Wongsuvan, Gumphol, ...

Ashdown's medium, Burkholderia pseudomallei selective agar (BPSA), and a commercial Burkholderia cepacia medium were compared for their abilities to grow B. pseudomallei from 155 clinical specimens...

Open-Label Randomized Trial of Oral Trimethoprim-Sulfamethoxazole, Doxycycline, and Chloramphenicol Compared with Trimethoprim-Sulfamethoxazole and Doxycycline for Maintenance Therapy of Melioidosis

Chaowagul, Wipada, Chierakul, Wirongrong, Simpson, Andrew J., Short, Jennifer M., Stepniewska, Kasia, Maharjan, Bina, ...

Melioidosis (infection caused by Burkholderia pseudomallei) requires a prolonged course of oral antibiotics following initial intravenous therapy to reduce the risk of relapse after cessation of...

Limited Polymorphism in the Dihydropteroate Synthetase Gene (dhps) of Plasmodium vivax Isolates from Thailand

Imwong, Mallika, Pukrittayakamee, Sasithon, Cheng, Qin, Moore, Catrin, Looareesuwan, Sornchai, Snounou, Georges, ...

The dhps sequences of 55 Plasmodium vivax isolates (39 from Thailand and 16 from elsewhere) revealed mutant Pvdhps at codons 383 and/or 553 (A → G) in 33 isolates, all from Thailand. Mutations of...

Pitfalls in Estimating Piperaquine Elimination

Tarning, Joel, Lindegårdh, Niklas, Annerberg, Anna, Singtoroj, Thida, Day, Nicholas P. J., Ashton, Michael, ...

By using a sensitive new assay, the terminal elimination half-life of the antimalarial piperaquine in a healthy volunteer was estimated to be 33 days, which is longer than estimated previously. This...

Recurrent Melioidosis in Patients in Northeast Thailand Is Frequently Due to Reinfection Rather than Relapse

Maharjan, Bina, Chantratita, Narisara, Vesaratchavest, Mongkol, Cheng, Allen, Wuthiekanun, Vanaporn, Chierakul, Wirongrong, ...

Human melioidosis is associated with a high rate of recurrent disease, despite adequate antimicrobial treatment. Here, we define the rate of relapse versus the rate of reinfection in 116 patients...

How Clonal Is Staphylococcus aureus?

Feil, Edward J., Cooper, Jessica E., Grundmann, Hajo, Robinson, D. Ashley, Enright, Mark C., Berendt, Tony, ...

Staphylococcus aureus is an important human pathogen and represents a growing public health burden owing to the emergence and spread of antibiotic-resistant clones, particularly within the hospital...

Manslaughter by Fake Artesunate in Asia—Will Africa Be Next?

Newton, Paul N, McGready, Rose, Fernandez, Facundo, Green, Michael D, Sunjio, Manuela, Bruneton, Carinne, ...

Fake artesunate could compromise the hope that artemisinin-based combination therapy offers for malaria control in Africa and Asia.

Transmission-Blocking Activities of Quinine, Primaquine, and Artesunate

Chotivanich, Kesinee, Sattabongkot, Jetsumon, Udomsangpetch, Rachanee, Looareesuwan, Sornchai, Day, Nicholas P. J., Coleman, Russell E., ...

The infectivity of Plasmodium falciparum gametocytes after exposure in vitro to quinine, artesunate, and primaquine was assessed in Anopheles dirus, a major vector of malaria in Southeast Asia....

Nonrandom Distribution of Burkholderia pseudomallei Clones in Relation to Geographical Location and Virulence

Vesaratchavest, Mongkol, Tumapa, Sarinna, Day, Nicholas P. J., Wuthiekanun, Vanaporn, Chierakul, Wirongrong, Holden, Matthew T. G., ...

Burkholderia pseudomallei is a soil-dwelling saprophyte and the causative agent of melioidosis, a life-threatening human infection. Most cases are reported from northeast Thailand and northern...

Recombination within natural populations of pathogenic bacteria: Short-term empirical estimates and long-term phylogenetic consequences

Feil, Edward J., Holmes, Edward C., Bessen, Debra E., Chan, Man-Suen, Day, Nicholas P. J., Enright, Mark C., ...

The identification of clones within bacterial populations is often taken as evidence for a low rate of recombination, but the validity of this inference is rarely examined. We have used statistical...

Epidemic Typhoid in Vietnam: Molecular Typing of Multiple-Antibiotic-Resistant Salmonella enterica Serotype Typhi from Four Outbreaks

Connerton, Phillippa, Wain, John, Hien, Tran T., Ali, Tahir, Parry, Christopher, Chinh, Nguyen T., ...

Multidrug-resistant Salmonella enterica serotype Typhi isolates from four outbreaks of typhoid fever in southern Vietnam between 1993 and 1997 were compared. Pulsed-field gel electrophoresis,...

Multilocus Sequence Typing for Characterization of Methicillin-Resistant and Methicillin-Susceptible Clones of Staphylococcus aureus

Enright, Mark C., Day, Nicholas P. J., Davies, Catrin E., Peacock, Sharon J., Spratt, Brian G.

A multilocus sequence typing (MLST) scheme has been developed for Staphylococcus aureus. The sequences of internal fragments of seven housekeeping genes were obtained for 155 S. aureus isolates from...

Quantitation of Bacteria in Bone Marrow from Patients with Typhoid Fever: Relationship between Counts and Clinical Features

Wain, John, Bay, Phan Van Be, Vinh, Ha, Duong, Nguyen M., Diep, To Song, Walsh, Amanda L., ...

Enteric fever is the only bacterial infection of humans for which bone marrow examination is routinely recommended. A prospective study of the concentrations of bacteria in the bone marrow and their...

Virulent Combinations of Adhesin and Toxin Genes in Natural Populations of Staphylococcus aureus

Peacock, Sharon J., Moore, Catrin E., Justice, Anita, Kantzanou, Maria, Story, Lisa, Mackie, Kathryn, ...

Most cases of severe Staphylococcus aureus disease cannot be explained by the action of a single virulence determinant, and it is likely that a number of factors act in combination during the...

Emergence in Vietnam of Streptococcus pneumoniae Resistant to Multiple Antimicrobial Agents as a Result of Dissemination of the Multiresistant Spain23F-1 Clone

Parry, Christopher M., Duong, Nguyen Minh, Zhou, Jiaji, Mai, Nguyen Thi Hoang, Diep, To Song, Thinh, Le Quoc, ...

Surveillance for Streptococcus pneumoniae resistant to penicillin and other antimicrobial agents is necessary to define the optimal empirical antibiotic therapy for meningitis in resource-poor...

How Clonal Is Staphylococcus aureus?

Feil, Edward J., Cooper, Jessica E., Grundmann, Hajo, Robinson, D. Ashley, Enright, Mark C., Berendt, Tony, ...

Staphylococcus aureus is an important human pathogen and represents a growing public health burden owing to the emergence and spread of antibiotic-resistant clones, particularly within the hospital...

Determinants of Acquisition and Carriage of Staphylococcus aureus in Infancy

Peacock, Sharon J., Justice, Anita, Griffiths, D., Kantzanou, M. N., Crook, Derrick, ...

Nasal carriage of Staphylococcus aureus is a major risk factor for invasive S. aureus disease. The aim of this study was to define factors associated with carriage. We conducted a prospective,...

Complete genomes of two clinical Staphylococcus aureus strains: Evidence for the rapid evolution of virulence and drug resistance

Holden, Matthew T. G., Feil, Edward J., Lindsay, Jodi A., Peacock, Sharon J., Day, Nicholas P. J., Enright, Mark C., ...

Staphylococcus aureus is an important nosocomial and community-acquired pathogen. Its genetic plasticity has facilitated the evolution of many virulent and drug-resistant strains, presenting a major...

Evaluation of Immunoglobulin M (IgM) and IgG Rapid Cassette Test Kits for Diagnosis of Melioidosis in an Area of Endemicity

Wuthiekanun, Vanaporn, Amornchai, Premjit, Chierakul, Wirongrong, Cheng, Allen C., White, Nicholas J., Peacock, Sharon J., ...

An enzyme-linked immunosorbent assay-based rapid cassette immunoglobulin G (IgG) and IgM immunochromogenic test kit was compared to the indirect hemagglutination test (IHA) for the diagnosis of acute...

Lack of Association between Toll-Like Receptor 2 Polymorphisms and Susceptibility to Severe Disease Caused by Staphylococcus aureus

Moore, Catrin E., Segal, Shelley, Berendt, Anthony R., Hill, Adrian V. S., Day, Nicholas P. J.

To investigate a putative link between genetically determined variations in Toll-like receptor 2 (TLR2) and the occurrence of severe Staphylococcus aureus infection, the functional Arg753Gln...

In Vivo Assessment of Drug Efficacy against Plasmodium falciparum Malaria: Duration of Follow-Up

Stepniewska, Kasia, Taylor, Walter R.J., Mayxay, Mayfong, Price, Ric, Smithuis, Frank, Guthmann, Jean-Paul, ...

To determine the optimum duration of follow-up for the assessment of drug efficacy against Plasmodium falciparum malaria, 96 trial arms from randomized controlled trials (RCTs) with follow-up of 28...

Detection of Burkholderia pseudomallei in Soil within the Lao People's Democratic Republic

Wuthiekanun, Vanaporn, Mayxay, Mayfong, Chierakul, Wirongrong, Phetsouvanh, Rattanaphone, Cheng, Allen C., White, Nicholas J, ...

Clinical cases of melioidosis caused by the saprophyte Burkholderia pseudomallei were first noted in the Lao People's Democratic Republic (PDR) in 1999. In this study, 36% of 110 soil samples in...

Rapid Immunofluorescence Microscopy for Diagnosis of Melioidosis

Wuthiekanun, Vanaporn, Desakorn, Varunee, Wongsuvan, Gumphol, Amornchai, Premjit, Cheng, Allen C., Maharjan, Bina, ...

An immunofluorescent (IF) method that detects Burkholderia pseudomallei in clinical specimens within 10 min was devised. The results of this rapid method and those of an existing IF method were...

Role and Significance of Quantitative Urine Cultures in Diagnosis of Melioidosis

Limmathurotsakul, Direk, Wuthiekanun, Vanaporn, Chierakul, Wirongrong, Cheng, Allen C., Maharjan, Bina, Chaowagul, Wipada, ...

Melioidosis is associated with significant mortality in countries in which it is endemic. Previous studies have demonstrated that quantitative Burkholderia pseudomallei counts in blood are predictive...

Estimation of the Total Parasite Biomass in Acute Falciparum Malaria from Plasma PfHRP2

Dondorp, Arjen M, Desakorn, Varunee, Pongtavornpinyo, Wirichada, Sahassananda, Duangjai, Silamut, Kamolrat, Chotivanich, Kesinee, ...

Measuring sequestered parasites using plasma PfHRP2 concentrations may provide a more accurate estimate of total parasite mass and hence severity in falciparum malaria.

Antibodies from Patients with Melioidosis Recognize Burkholderia mallei but Not Burkholderia thailandensis Antigens in the Indirect Hemagglutination Assay

Tiyawisutsri, Rachaneeporn, Peacock, Sharon J., Langa, Sayan, Limmathurotsakul, Direk, Cheng, Allen C., Chierakul, Wirongrong, ...

The indirect hemagglutination assay routinely used to detect antibodies to Burkholderia pseudomallei was modified to detect cross-reactivity of antibodies to B. pseudomallei, B. mallei, and B....

Comparison of Ashdown's Medium, Burkholderia cepacia Medium, and Burkholderia pseudomallei Selective Agar for Clinical Isolation of Burkholderia pseudomallei

Peacock, Sharon J., Chieng, Grace, Cheng, Allen C., Dance, David A. B., Amornchai, Premjit, Wongsuvan, Gumphol, ...

Ashdown's medium, Burkholderia pseudomallei selective agar (BPSA), and a commercial Burkholderia cepacia medium were compared for their abilities to grow B. pseudomallei from 155 clinical specimens...

Open-Label Randomized Trial of Oral Trimethoprim-Sulfamethoxazole, Doxycycline, and Chloramphenicol Compared with Trimethoprim-Sulfamethoxazole and Doxycycline for Maintenance Therapy of Melioidosis

Chaowagul, Wipada, Chierakul, Wirongrong, Simpson, Andrew J., Short, Jennifer M., Stepniewska, Kasia, Maharjan, Bina, ...

Melioidosis (infection caused by Burkholderia pseudomallei) requires a prolonged course of oral antibiotics following initial intravenous therapy to reduce the risk of relapse after cessation of...

Limited Polymorphism in the Dihydropteroate Synthetase Gene (dhps) of Plasmodium vivax Isolates from Thailand

Imwong, Mallika, Pukrittayakamee, Sasithon, Cheng, Qin, Moore, Catrin, Looareesuwan, Sornchai, Snounou, Georges, ...

The dhps sequences of 55 Plasmodium vivax isolates (39 from Thailand and 16 from elsewhere) revealed mutant Pvdhps at codons 383 and/or 553 (A → G) in 33 isolates, all from Thailand. Mutations of...

Pitfalls in Estimating Piperaquine Elimination

Tarning, Joel, Lindegårdh, Niklas, Annerberg, Anna, Singtoroj, Thida, Day, Nicholas P. J., Ashton, Michael, ...

By using a sensitive new assay, the terminal elimination half-life of the antimalarial piperaquine in a healthy volunteer was estimated to be 33 days, which is longer than estimated previously. This...

Recurrent Melioidosis in Patients in Northeast Thailand Is Frequently Due to Reinfection Rather than Relapse

Maharjan, Bina, Chantratita, Narisara, Vesaratchavest, Mongkol, Cheng, Allen, Wuthiekanun, Vanaporn, Chierakul, Wirongrong, ...

Human melioidosis is associated with a high rate of recurrent disease, despite adequate antimicrobial treatment. Here, we define the rate of relapse versus the rate of reinfection in 116 patients...

Manslaughter by Fake Artesunate in Asia—Will Africa Be Next?

Newton, Paul N, McGready, Rose, Fernandez, Facundo, Green, Michael D, Sunjio, Manuela, Bruneton, Carinne, ...

Fake artesunate could compromise the hope that artemisinin-based combination therapy offers for malaria control in Africa and Asia.

Transmission-Blocking Activities of Quinine, Primaquine, and Artesunate

Chotivanich, Kesinee, Sattabongkot, Jetsumon, Udomsangpetch, Rachanee, Looareesuwan, Sornchai, Day, Nicholas P. J., Coleman, Russell E., ...

The infectivity of Plasmodium falciparum gametocytes after exposure in vitro to quinine, artesunate, and primaquine was assessed in Anopheles dirus, a major vector of malaria in Southeast Asia....

Nonrandom Distribution of Burkholderia pseudomallei Clones in Relation to Geographical Location and Virulence

Vesaratchavest, Mongkol, Tumapa, Sarinna, Day, Nicholas P. J., Wuthiekanun, Vanaporn, Chierakul, Wirongrong, Holden, Matthew T. G., ...

Burkholderia pseudomallei is a soil-dwelling saprophyte and the causative agent of melioidosis, a life-threatening human infection. Most cases are reported from northeast Thailand and northern...