J Med Microbiol, 2004 Jan, 53(Pt 1), 35 - 45 Identification and interrogation of highly informative single nucleotide polymorphism sets defined by bacterial multilocus sequence typing databases; Robertson GA et al.; A unified, bioinformatics-driven, single nucleotide polymorphism (SNP)-based approach to microbial genotyping has been developed . Multilocus sequence typing (MLST) databases consist of known variants of standardized housekeeping genes . Normally, seven fragments are defined; a sequence type (ST) consists of the variants of these fragments that are found in a particular isolate . A computer program that can identify highly informative sets of SNPs in entire MLST databases has been constructed . The SNPs either define a particular user-specified ST or provide a high value for Simpson's index of diversity (D), and may thus be generally applicable to that species . SNP sets that are diagnostic for Neisseria meningitidis ST-11 and ST-42, and high-D SNP sets for N . meningitidis and Staphylococcus aureus, were identified and real-time PCR methods to interrogate these SNPs were demonstrated . High-D SNP sets were also identified in other MLST databases . This widely applicable approach allows rapid genetic fingerprinting of infectious agents. Microbiology, 2003 Dec, 149(Pt 12), 3423 - 35 Identification of functionally important regions of a haemoglobin receptor from Neisseria meningitidis; Perkins-Balding D et al.; The HmbR outer-membrane receptor enables Neisseria meningitidis to use haemoglobin (Hb) as a source of iron . This protein functions by binding Hb, removing haem from it, and releasing the haem into the periplasm . Functionally important HmbR receptor domains were discerned using a series of HmbR deletions and site-directed mutations . Mutations exhibiting similar defective phenotypes in N . meningitidis fell into two groups . The first group of mutations affected Hb binding and were located in putative extracellular loops (L) L2 (amino acid residues (aa) 192-230) and L3 (aa 254-284) . The second group of mutations resulted in a failure to utilize Hb but proficiency in Hb binding was retained . These mutations localized to the putative extracellular loops L6 (aa 420-462) and L7 (aa 486-516) . A highly conserved protein motif found in all haem/Hb receptors, within putative extracellular loop L7 of HmbR, is essential for Hb utilization but not required for Hb binding . This finding suggests a mechanistic involvement of this motif in haem removal from Hb . In addition, an amino-terminal deletion in the putative cork-like domain of HmbR affected Hb usage but not Hb binding . This result supports a role of the cork domain in utilization steps that are subsequent to Hb binding. J Clin Microbiol, 2003 Dec, 41(12), 5783 - 6 First report of capsule replacement among electrophoretic type 37 Neisseria meningitidis strains in Italy; Stefanelli P et al.; This report describes the C-to-B capsular switching in four Neisseria meningitidis strains belonging to the electrophoretic type 37 (ET-37) complex . In particular, one strain belonged to the new sequence type 1860, which was first detected in the year 2000 in Italy and is now frequently isolated . The presence of switched serogroup B strains deserves special attention if they prove as able to spread as their serogroup C progenitors belonging to the hypervirulent ET-37 complex. J Clin Microbiol, 2003 Dec, 41(12), 5609 - 14 Persistence of two genotypes of Neisseria gonorrhoeae during transmission; Martin IM et al.; Isolates of Neisseria gonorrhoeae were tested using a highly discriminatory typing method, opa typing, to examine the genetic diversity over a 2-year study period of isolates from all consecutive patients with gonorrhea attending the Genitourinary Medicine clinic in Sheffield, United Kingdom . Two opa genotypes were detected throughout the 2-year time period and comprised 41% of all strains tested . The persistence of two opa types was investigated further to determine the apparent genetic stability, by examining the ability of isolates to undergo intragenic and intergenic recombination and mutation in vitro . Intragenic recombination or mutation involving the opa genes of N . gonorrhoeae in the selected isolates was not detected, but intergenic recombination did occur . opa genes of N . gonorrhoeae in vivo appear to diversify primarily through intergenic recombination . Intergenic recombination in vivo would require the presence of a mixed gonococcal infection, in which an individual is concurrently colonized with more than one strain of N . gonorrhoeae . We propose that the level of diversity of opa genotypes in a population is linked to the degree of sexual mixing of individuals and the incidence of mixed infections of N . gonorrhoeae. Biochemistry, 2003 Dec 16, 42(49), 14614 - 25 Neisseria gonorrhoeae penicillin-binding protein 3 exhibits exceptionally high carboxypeptidase and beta-lactam binding activities; Stefanova ME et al.; A soluble form of penicillin-binding protein 3 (PBP 3) from Neisseria gonorrhoeae was expressed and purified from Escherichia coli and characterized for its interaction with beta-lactam antibiotics, its catalytic properties with peptide and peptidoglycan substrates, and its role in cell viability and morphology . PBP 3 had an unusually high k(2)/K' value relative to other PBPs for acylation with penicillin (7.7 x 10(5) M(-1) s(-1)) at pH 8.5 at 25 degrees C and hydrolyzed bound antibiotic very slowly (k(3) < 4.6 x 10(-5) s(-1), t(1/2) > 230 min) . PBP 3 also demonstrated exceptionally high carboxypeptidase activity with a k(cat) of 580 s(-1) and a k(cat)/K(m) of 1.8 x 10(5) M(-1) s(-1) with the substrate N(alpha)-Boc-N(epsilon)-Cbz-L-Lys-D-Ala-D-Ala . This is the highest k(cat) value yet reported for a PBP or other serine peptidases . Activity against a approximately D-Ala-D-Lac peptide substrate was approximately 2-fold lower than against the analogous approximately D-Ala-D-Ala peptide substrate, indicating that deacylation is rate determining for both amide and ester hydrolysis . The pH dependence profiles of both carboxypeptidase activity and beta-lactam acylation were bell-shaped with maximal activity at pH 8.0-8.5 . PBP 3 displayed weak transpeptidase activity in a model transpeptidase reaction but was active as an endopeptidase, cleaving dimeric peptide cross-links . Deletion of PBP 3 alone had little effect on viability, growth rate, and morphology of N . gonorrhoeae, although deletion of both PBP 3 and PBP 4, the other low-molecular-mass PBP in N . gonorrhoeae, resulted in a decreased growth rate and marked morphological abnormalities. Br J Ophthalmol, 2003 Dec, 87(12), 1449 - 52 A double application approach to ophthalmia neonatorum prophylaxis; Isenberg SJ et al.; AIMS: To investigate if a second drop of 2.5% povidone-iodine ophthalmic solution placed within the first postnatal day would achieve better prophylaxis against ophthalmia neonatorum than a single drop applied at birth . METHODS: A masked, prospective, controlled trial was conducted over a 2 year period in a Kenyan hospital . Randomisation was achieved by alternating weeks of one or two eye drop application to both eyes . All 719 neonates received one drop of the povidone-iodine solution to both eyes at birth, while 317 received a second drop at hospital discharge or 24 (SD 4) hours after delivery, whichever was first . All infants developing conjunctivitis within a month after birth underwent microbiological analysis using Gram and Giemsa stains, direct fluorescent antibody assay for Chlamydia trachomatis, and culture . RESULTS: Of the neonates receiving the one eye drop application, 18.4% returned with a red eye with discharge, 4.0% had organisms found on the initial smear, and 8.2% had a positive culture . The corresponding proportions for the multidrop group were 24.3%, 4.7%, and 10.4% . Of those returning with an inflamed eye, there were no cases of Neisseria gonorrhoeae, 4.2% in the single dose group and 3.9% in the double dose group were positive for C trachomatis, and 5.4% and 6.5% respectively for Staphylococcus aureus . At discharge, the eyelid oedema score of the double dose group was mildly greater than the single dose group (1.4 (0.67) v 1.2 (0.73), p=0.0002) . There was no statistically significant difference between the groups in any other category . CONCLUSION: There is no advantage to administering povidone-iodine prophylaxis against ophthalmia neonatorum twice in the first postnatal day over a single application at birth. J Virol, 2003 Dec, 77(24), 13396 - 8 Neutralization of enteric coronaviruses with Escherichia coli cells expressing single-chain Fv-autotransporter fusions; Veiga E et al.; We report here that fusions of single-chain antibodies (scFvs) to the autotransporter beta domain of the IgA protease of Neisseria gonorrhoeae are instrumental in locating virus-neutralizing activity on the cell surface of Escherichia coli . E . coli cells displaying scFvs against the transmissible gastroenteritis coronavirus on their surface blocked in vivo the access of the infectious agent to cultured epithelial cells . This result raises prospects for antiviral strategies aimed at hindering the entry into target cells by bacteria that naturally colonize the same intestinal niches. J Bacteriol, 2003 Dec, 185(24), 7145 - 52 FarR regulates the farAB-encoded efflux pump of Neisseria gonorrhoeae via an MtrR regulatory mechanism; Lee EH et al.; The farAB operon of Neisseria gonorrhoeae encodes an efflux pump which mediates gonococcal resistance to antibacterial fatty acids . It was previously observed that expression of the farAB operon was positively regulated by MtrR, which is a repressor of the mtrCDE-encoded efflux pump system (E.-H . Lee and W . M . Shafer, Mol . Microbiol . 33:839-845, 1999) . This regulation was believed to be indirect since MtrR did not bind to the farAB promoter . In this study, computer analysis of the gonococcal genome sequence database, lacZ reporter fusions, and gel mobility shift assays were used to elucidate the regulatory mechanism by which expression of the farAB operon is modulated by MtrR in gonococci . We identified a regulatory protein belonging to the MarR family of transcriptional repressors and found that it negatively controls expression of farAB by directly binding to the farAB promoter . We designated this regulator FarR to signify its role in regulating the farAB operon . We found that MtrR binds to the farR promoter, thereby repressing farR expression . Hence, MtrR regulates farAB in a positive fashion by modulating farR expression . This MtrR regulatory cascade seems to play an important role in adjusting levels of the FarAB and MtrCDE efflux pumps to prevent their excess expression in gonococci. West Indian Med J, 2003 Sep, 52(3), 228 - 30 Decrease in the incidence of tetracycline resistance in strains of Neisseria gonorrhoeae in the nineties; Bodonaik NC; Antibiotic resistance determined by standard disc-diffusion method on GC agar with supplement B in 583 strains of Neisseria gonorrhoeae encountered between 1991 and 1996 at the University Hospital of the West Indies, Kingston, Jamaica, were analyzed . The level of penicillin resistance varied between 40% and 28% over the years . Tetracycline resistance fell from 44.2% in 1991 to 23.9% in 1996 . Twenty-one per cent of the isolates were resistant simultaneously to both penicillin and tetracycline in 1991 . The percentage of such strains decreased to 6.5% in 1996 . Ceftriaxone was introduced as a first line drug in treatment of gonococcal infections in the late 1980s . The declining trend of tetracycline resistance may be due to a decrease in the usage of tetracycline in recent years. Sex Transm Dis, 2003 Dec, 30(12), 896 - 900 Trends of chromosomally mediated antimicrobial resistance in Neisseria gonorrhoeae in Canada: 1994-1999; Ng LK et al.; BACKGROUND AND OBJECTIVES: We monitored the trends of chromosomally mediated resistant Neisseria gonorrhoeae (CMRNG) in Canada . Chromosomally resistant N . gonorrhoeae (CMRNG) were defined as having resistance to 3 antibiotics: penicillin (minimum inhibitory concentration {MIC} > or =2.0 mg/L), tetracycline (MIC > or =2.0 mg/L and < or =8.0 mg/L), and erythromycin (MIC > or =2.0 mg/L) . GOAL: The goal was to provide surveillance data for public health interventions for the control of gonococcal infections . STUDY DESIGN: Antibiotic susceptibility tests were performed on N . gonorrhoeae isolates obtained from 1994 to 1999 in Canada . Strains were further characterized by auxotype (A), serovar (S), and plasmid profile (P) . RESULTS: Between 1994 and 1999, 19.2% of strains were CMRNG, 12.9% had a combined resistance to tetracycline and erythromycin, and 4.7% were resistant to tetracycline . The incidence of ciprofloxacin resistance and azithromycin resistance was 2.3% and 0.8%, respectively . CONCLUSION: This survey of N . gonorrhoeae provides strain characterization data and temporal trends of strains in the Canadian population . CMRNG strains are on the rise, and the continual monitoring and characterization of these strains is important for the evaluation of current recommended antibiotic therapies used in Canada. Sex Transm Dis, 2003 Dec, 30(12), 886 - 9 Screening for Neisseria gonorrhoeae and Chlamydia trachomatis in men who have sex with men at male-only saunas; Lister NA et al.; BACKGROUND AND OBJECTIVES: In response to increases in sexually transmissible infections (STI) and HIV infection rates among men who have sex with men (MSM), the current study aimed to investigate the feasibility of a screening program at male-only saunas in Melbourne, Australia . GOAL: The goal was to determine (1) the participation rate, and the proportion whom obtain test results; (2) the prevalence of gonorrhea and chlamydia; and (3) to evaluate risk factors for STI acquisition . STUDY DESIGN: We used a cross-sectional design . Pharyngeal, rectal, and urethral specimens were collected from participants, and tested for Chlamydia trachomatis and Neisseria gonorrhoeae by polymerase chain reaction (PCR) . RESULTS: There was a participation rate of 24% (n=521), and 70% obtained their test results . The infection rate in those who failed to collect their results was no different than those seeking theirs . The proportion of participants with PCR-detected gonorrhea and/or chlamydia infection was high, 10.7% . The presence of infection was associated with seeking sexual health care in the last year . CONCLUSION: The high prevalence rate of gonorrhea and chlamydia supports the concept of a screening program in Melbourne male-only saunas . The low participation rate has highlighted the need to consider alternative methods for making contact with men in the saunas or offering incentives to participate in future screening programs . Although anonymous participation encouraged participation for some men, future programs should attempt to obtain contact details for follow up of positive test results. Infect Immun, 2003 Dec, 71(12), 6892 - 8 Identification and characterization of pptA: a gene involved in the phase-variable expression of phosphorylcholine on pili of Neisseria meningitidis; Warren MJ et al.; Pili of pathogenic Neisseria are major virulence factors associated with adhesion, cytotoxicity, twitching motility, autoaggregation, and DNA transformation . Pili are modified posttranslationally by the addition of phosphorylcholine . However, no genes involved in either the biosynthesis or the transfer of phosphorylcholine in Neisseria meningitidis have been identified . In this study, we identified five candidate open reading frames (ORFs) potentially involved in the biosynthesis or transfer of phosphorylcholine to pilin in N . meningitidis . Insertional mutants were constructed for each ORF in N . meningitidis strain C311#3 to determine their effect on phosphorylcholine expression . The effect of the mutant ORFs on the modification by phosphorylcholine was analyzed by Western analysis with phosphorylcholine-specific monoclonal antibody TEPC-15 . Analysis of the mutants showed that ORF NMB0415, now defined as pptA (pilin phosphorylcholine transferase A), is involved in the addition of phosphorylcholine to pilin in N . meningitidis . Additionally, the phase variation (high frequency on-off switching of expression) of phosphorylcholine on pilin is due to changes in a homopolymeric guanosine tract in pptA. Infect Immun, 2003 Dec, 71(12), 6844 - 9 Conformational epitopes recognized by protective anti-neisserial surface protein A antibodies; Hou VC et al.; NspA is a conserved membrane protein that elicits protective antibody responses in mice against Neisseria meningitidis . A recent crystallographic study showed that NspA adopts an eight-stranded beta-barrel structure when reconstituted in detergent . In order to define the segments of NspA-containing epitopes recognized by protective murine anti-NspA antibodies, we studied the binding of two bactericidal and protective anti-NspA monoclonal antibodies (MAbs), AL12 and 14C7 . Neither MAb binds to overlapping synthetic peptides (10-mers, 12-mers, and cyclic 12-mers) corresponding to the entire mature sequence of NspA, or to denatured recombinant NspA (rNspA), although binding to the protein can be restored by refolding in liposomes . Based on the ability of the two MAbs to bind to Escherichia coli microvesicles prepared from a set of rNspA variants created by site-specific mutagenesis, the most important contacts between the MAbs and NspA appear to be located within the LGG segment of loop 3 . The conformation of loop 2 also appears to be an important determinant, as particular combinations of residues in this segment resulted in loss of antibody binding . Thus, the two anti-NspA MAbs recognize discontinuous conformational epitopes that result from the close proximity of loops 2 and 3 in the three-dimensional structure of NspA . The data suggest that optimally immunogenic vaccines using rNspA will require formulations that permit proper folding of the protein. J Mol Biol, 2003 Dec 5, 334(4), 625 - 37 The crystal structure of murine CMP-5-N-acetylneuraminic acid synthetase; Krapp S et al.; Sialic acids are activated by CMP-5-N-acetylneuraminic acid synthetase prior to their transfer onto oligo- or polysaccharides . Here, we present the crystal structure of the N-terminal catalytically active domain of the murine 5-N-acetylneuraminic acid synthetase in complex with the reaction product . In contrast to the previously solved structure of 5-N-acetylneuraminic acid synthetase from Neisseria meningitidis and the related CMP-KDO-synthetase of Escherichia coli, the murine enzyme is a tetramer, which was observed with the active sites closed . In this conformation a loop is shifted by 6A towards the active site and thus an essential arginine residue can participate in catalysis . Furthermore, a network of intermolecular salt-bridges and hydrogen bonds in the dimer as well as hydrophobic interfaces between two dimers indicate a cooperative behaviour of the enzyme . In addition, a complex regulation of the enzyme activity is proposed that includes phosphorylation and dephosphorylation. Curr Issues Mol Biol, 2004 Jan, 6(1), 17 - 27 The genome revolution in vaccine research; Capecchi B et al.; The conventional approach to vaccine development is based on dissection of the pathogen using biochemical, immunological and microbiological methods . Although successful in several cases, this approach has failed to provide a solution to prevent several major bacterial infections . The availability of complete genome sequences in combination with novel advanced technologies, such as bioinformatics, microarrays and proteomics, have revolutionized the approach to vaccine development and provided a new impulse to microbial research . The genomic revolution allows the design of vaccines starting from the prediction of all antigens in silico, independently of their abundance and without the need to grow the pathogen in vitro . This new genome-based approach, which we have named "Reverse Vaccinology", has been successfully applied for Neisseria meningitidis serogroup B for which conventional strategies have failed to provide an efficacious vaccine . The concept of "Reverse Vaccinology" can be easily applied to all the pathogens for which vaccines are not yet available and can be extended to parasites and viruses. APMIS, 2003 Nov, 111(11), 1060 - 6 Molecular characterisation of group A Neisseria meningitidis isolated in Sudan 1985-2001; Jacobsson S et al.; A total of 33 group A Neisseria meningitidis (Mc) isolates, collected in Sudan between 1985 and 2001, were studied in order to describe the changes over time in a country within the meningitis belt of Africa . The isolates were characterised by traditional phenotypic methods (serogrouping, serotyping, serosubtyping and antibiogram) and molecular techniques (genosubtyping, pulsed-field gel electrophoresis {PFGE} with restriction endonucleases SpeI and NheI, and multilocus sequence typing {MLST}) . Three clones of group A Mc were identified: one before 1988 (sulphadiazine sensitive, serotype 4, genosubtype P1.7,13-1,35-1, sequence type 4 {ST-4}); another during and after the 1988 epidemic (sulphadiazine resistant, serotype 4, genosubtype P1.20,9,35-1, ST-5); and a third causing the 1999 epidemic (sulphadiazine resistant, serotype 4, genosubtype P1.20,9,35-1, ST-7) . The first clone showed major differences compared to the other two . The second and third clones had many similarities with differences in only a single gene (pgm) in the MLST (47 of the 450 bp) but significant other differences according to the PFGE patterns . Within the clones, genosubtyping and MLST gave identical information (except one base substitution in the aroE gene in one isolate) . However, the PFGE patterns showed changes over time within the clones, where SpeI revealed somewhat more diversity than NheI. Int J STD AIDS, 2003 Nov, 14(11), 727 - 31 Gonorrhoea resurgence in Canada; Hansen L et al.; After several years of decline, reported gonorrhoea rates in Canada have recently increased substantially . National goals for gonorrhoea control were developed in 1997, but it appears that reliance on secular trends is insufficient to attain the goal of eliminating locally transmitted infection by Neisseria gonorrhoeae by 2010 . We have examined disease surveillance reports from 1994 to 2001 inclusive to assess demographic and epidemiologic trends in reported cases of gonococcal infection . Since 1997, reported cases have increased by 53% among men and 33% among women . The largest proportion of cases in women is in those aged 15-24; the most dramatic increase in males has been among those aged 30-39 . Reasons for the resurgence remain unclear, but disease reports indicate that renewed attention to enhanced surveillance and targeted prevention are essential for gonorrhoea control in Canada. Scand J Infect Dis, 2003, 35(9), 614 - 8 Neisserial Opa proteins: impact on colonization, dissemination and immunity; Gray-Owen SD; The pathogenic Neisseria sp . encode a family of phase-variable and antigenically distinct Opa proteins that allow bacterial attachment to virtually every cell type encountered during infection . Some Opa variants bind cell surface-expressed heparan sulfate proteoglycans, including members of the syndecan family of receptors, and extracellular matrix proteins such as fibronectin and vitronectin . Other variants bind members of the carcinoembryonic antigen family of cellular adhesion molecules . Depending on the Opa variant(s) expressed, these receptor interactions can allow neisserial entry and transcellular transcytosis across polarized epithelial cell monolayers, entry into endothelial cells, suppression of lymphocyte function and/or bacterial engulfment and killing by neutrophils . Recent advances in our understanding of how these Opa protein-mediated interactions influence the host cellular response are discussed in the context of their impact on various stages of neisserial infection. Akush Ginekol (Sofiia), 2003, 42 Suppl 2, 3 - 5 {Is there a correlation between the vaginal colonization with group B streptococci and premature deliveries?}; Kovachev E et al.; The study covered 110 pregnant females during the period from January 1, 2002 till April 30, 2003 . Nine females (8.18%) delivered premature newborns . Samples were taken from the posterior vaginal fornix and canalis cervicalis in the 18th and 24th gestational week . The preparations stained after Gram were examined under light microscope . Microbial cultures on blood agar were examined, too . It was established that 18 or 16.36% of all the cases presented with cultures positive for group B streptococci (Str . agalactiae) and Ureaplasma urealythicum . Some other microbial flora representatives such as Chlamydia trachomatis, Neisseria gonorrhoea and Trichomonas vaginalis were additionally identified . The independent colonization with Str . agalactiae prior to the 18th gestational week does not relate to the spontaneous abortions and premature deliveries at all . On the other hand, the colonization with Group B streptococci or their symbiosis with other microorganisms after the 23rd-24th gestational week displays a certain correlation with the premature births. J Obstet Gynaecol, 2003 Nov, 23(6), 637 - 9 Prevalence of sexually transmitted diseases among pregnant women in Ilorin, Nigeria; Aboyeji AP et al.; In a cross-sectional study, 230 pregnant women attending the antenatal clinic of the University of Ilorin Teaching Hospital (UITH), Ilorin, Nigeria from January 2000 to December 2000 were screened randomly to determine the prevalence of common STDs among them, using conventional methods . One hundred and fourteen (49.4%) of the subjects harboured various agents including Candida spp . (37.8%), Trichomonas vaginalis (4.7%), Gardnerella vaginalis (3.9%), syphilis (1.7%) and Neisseria gonorrhea (1.3%) . Risk factors associated with significant infection were young age and level of education . The importance of routine STD screening in pregnancy especially among the young and illiterate is advocated . It is recommended that routine screening for STDs should be incorporated into antenatal care. Mol Microbiol, 2003 Nov, 50(3), 1055 - 67 NarE: a novel ADP-ribosyltransferase from Neisseria meningitidis; Masignani V et al.; Mono ADP-ribosyltransferases (ADPRTs) are a class of functionally conserved enzymes present in prokaryotic and eukaryotic organisms . In bacteria, these enzymes often act as potent toxins and play an important role in pathogenesis . Here we report a profile-based computational approach that, assisted by secondary structure predictions, has allowed the identification of a previously undiscovered ADP-ribosyltransferase in Neisseria meningitidis (NarE) . NarE shows structural homologies with E . coli heat-labile enterotoxin (LT) and cholera toxin (CT) and possesses ADP-ribosylating and NAD-glycohydrolase activities . As in the case of LT and CT, NarE catalyses the transfer of the ADP-ribose moiety to arginine residues . Despite the absence of a signal peptide, the protein is efficiently exported into the periplasm of Neisseria . The narE gene is present in 25 out of 43 strains analysed, is always present in ET-5 and Lineage 3 but absent in ET-37 and Cluster A4 hypervirulent lineages . When present, the gene is 100% conserved in sequence and is inserted upstream of and co-transcribed with the lipoamide dehydrogenase E3 gene . Possible roles in the pathogenesis of N . meningitidis are discussed. Clin Microbiol Infect, 2003 Sep, 9(9), 964 - 5 Infections by Neisseria meningitidis serogroup X in Spain; del Castillo CM et al.; We describe an atypical presentation of bacteremia caused by N . meningitidis serogroup X . By multilocus sequence typing the isolate was characterized to the sequence type 2139, which is not related with the clonal complex recently isolated in Africa . Since 1984, only six cases of serogroup X N . meningitidis infections have been diagnosed in Spain . Nevertheless, after the application of the conjugated vaccine, attention should be paid to the emergence of infections caused by unusual serogroups of N . meningitidis. FEMS Microbiol Lett, 2003 Nov 7, 228(1), 99 - 104 Prevalence and identification of tetracycline-resistant oral bacteria in children not receiving antibiotic therapy; Lancaster H et al.; The prevalence of tetracycline-resistant oral bacteria in healthy 4- and 6-year-old children who had not received antibiotics during the 3 months prior to sampling was investigated . Of the 47 children sampled, 46 harboured tetracycline-resistant bacteria . The median proportion of cultivable anaerobic and aerobic oral bacteria resistant to tetracycline was 1.1% and the MIC50 of these was 64 microg ml(-1) . The majority (56%) of tetracycline-resistant bacteria were resistant to at least one other antibiotic, usually erythromycin . The most commonly identified tetracycline-resistant bacteria were the oral streptococci (65%), the next most prevalent groups were Veillonella spp . (10%) and Neisseria spp . (9%) . The most frequently identified tetracycline resistance determinant was tet(M) . The results of this study have shown that tetracycline-resistant oral bacteria were widespread amongst the children studied. BMC Microbiol . 2003 Nov 12;3(1):23. Diversity in coding tandem repeats in related Neisseria spp; Jordan P et al.; BACKGROUND: Tandem repeats contained within coding regions can mediate phase variation when the repeated units change the reading frame of the coding sequence in a copy number dependent manner . Coding tandem repeats are those which do not alter the reading frame with copy number, and the changes in copy number of these repeats may then potentially alter the function or antigenicity of the protein encoded . Three complete neisserial genomes were analyzed and compared to identify coding tandem repeats where the number of copies of the repeat will have some structural consequence for the protein . This is the first study to address coding tandem repeats that may affect protein structures using comparative genomics, combined with a population survey to investigate which show interstrain variability . RESULTS: A total of 28 genes were identified . Of these, 22 contain coding tandem repeats that vary in copy number between the three sequenced strains, three strain specific genes were included for investigation on the basis of having >90% identity between repeated units, and three genes with repeated elements of >250 bp were included although no length variations were seen in the genomes . Amplification, and sequencing of repeats showing altered copy number, of these 28 coding tandem repeat containing regions, from a set of largely unrelated strains, revealed further repeat length variation in several cases . CONCLUSION: Eighteen genes were identified which have variation in repeat copy number between strains of the same species, twelve of which show greater diversity in repeat copy number than is present in the sequenced genomes . In some cases, this may reflect a mechanism for the generation of antigenic variation, as previously described in other species . However, some of the genes identified encode proteins with cytoplasmic functions, including sugar metabolism, DNA repair, and protein production, in which repeat length variation may have other functions . Coding tandem repeats appear to represent a largely unexplored mechanism of generating diversity in the Neisseria spp. Sex Transm Dis, 2003 Nov, 30(11), 866 - 70 Predictive value of clinical diagnostic codes for the CDC case definition of pelvic inflammatory disease (PID): implications for surveillance; Ratelle S et al.; BACKGROUND: Reporting of pelvic inflammatory disease (PID) from private providers could be incomplete because of time and staff constraints, lack of knowledge of reporting requirements and of case definitions . Reporting burden can be alleviated with the use of administrative data . GOAL: The goal of this study was to determine the validity of clinical diagnostic codes assigned in electronic medical records (EMR) for identifying PID and their use in enhancing surveillance . STUDY DESIGN: A random sample of 296 records with a PID International Classification of Diseases, 9th Revision (ICD-9), code (614.9) were reviewed to assess for the presence of the Centers for Disease Control and Prevention (CDC) criteria for the case definition of PID . We used the records meeting the CDC clinical case definition criteria as the reference standard to determine the sensitivity, specificity, and predictive values of various data elements . RESULTS: Used alone, the positive predictive value (PPV) of ICD-9 code 614.9 for a CDC case definition of PID was 18.1% . The PPV increased to 100% and 56% when the ICD-9 code visit was associated with a positive test for Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT), respectively . CONCLUSION: In this multispecialty group practice, a positive test for GC and CT coupled with ICD-9 code 614.9 could be used to enhance reporting of cases of PID. Sex Transm Dis, 2003 Nov, 30(11), 850 - 3 Acceptability of urine screening for Neisseria gonorrheae and Chlamydia trachomatis in adolescents at an urban emergency department; Monroe KW et al.; OBJECTIVE: The objective of this study was to determine the acceptability of urine screening for Neisseria gonorrhoeae and Chlamydia trachomatis in adolescents in a pediatric emergency department . STUDY DESIGN: We used a prospective enrollment of adolescents aged 14-20 visiting an urban pediatric emergency department . MAIN OUTCOME MEASURES: The main outcome measure was acceptance of urine STD screening rates . RESULTS: Of 1231 potential participants, 879 (71%) agreed to participate and 352 (29%) declined screening . Participants were similar to those refusing to participate in terms of gender . In multivariate analysis, age, race/ethnicity, and insurance status were associated with variation in sexually transmitted disease (STD) test acceptance, whereas the presence of a parent was not . Despite similar training, 1 of 3 recruiters had significantly lower acceptance rates than her peers . Overall, 10% of patients enrolled were found to have one or both infections . CONCLUSION: Urine screening for STDs can be efficiently conducted in an emergency department setting . This screening appears to be acceptable to most patients. Otol Neurotol, 2003 Nov, 24(6), 907 - 12 Sensorineural hearing loss in postmeningitic children; Wellman MB et al.; OBJECTIVE: To establish the proportion of children who develop sensorineural hearing loss after bacterial meningitis and to correlate such loss with patient factors . STUDY DESIGN: Retrospective case review . SETTING: McMaster University Children's Hospital, a tertiary referral center . PATIENTS: Children between the ages of 1 day and 18 years admitted to McMaster University Children's Hospital with a confirmed diagnosis of bacterial meningitis between January 1, 1991 and December 30, 2000 . INTERVENTIONS: Audiological assessment including auditory brainstem responses and cortical electric-response audiometry or standard audiometry . MAIN OUTCOME MEASURES: The nature of sensorineural hearing loss was assessed according to the degree (mild to profound) and course (transient versus permanent) . Correlations between sensorineural hearing loss and the patient's age, sex, duration of illness before admission, use of dexamethasone, concurrent neurologic complications, and types of pathogens were evaluated . Patterns of inpatient and outpatient audiological assessment were determined . RESULTS: Seventy-nine children had confirmed bacterial meningitis . Streptococcus pneumoniae accounted for 36.7 percent of all cases, followed-up by Neisseria meningitides (16.5%), group B Streptococcus (15.2%), and Hemophilus influenzae (13.9%) . Sixty-eight (86.1%) children underwent hearing assessment, either as inpatients or after discharge . Of the remaining 11 (13.9%) in whom audiological evaluation could not be confirmed, only two made mention of a referral . As such, a nonreferral rate of 11.4 percent was identified . Abnormal auditory brainstem response findings were present in 22 cases (32.3%), with 11 cases (13.9%) of permanent sensorineural hearing loss identified . A statistically significant association between sensorineural hearing loss and Streptococcus pneumoniae was found (p < 0.001) . No association between age, sex, duration of illness before admission, use of dexamethasone, and number of concurrent neurologic complications could be established . CONCLUSIONS: In our series, 11 children (13.9%) experienced permanent sensorineural hearing loss, consistent with previously reported rates of 5 to 35 percent within the pediatric population . Since introduction of the Hemophilus influenzae type B vaccine, Streptococcus pneumoniae has emerged as the dominant causative organism of bacterial meningitis in children . Our study additionally confirms the role of Streptococcus pneumoniae as a precipitant of sensorineural hearing loss (p < 0.001) . Audiological assessment in our series (86.1%) exceeds most of the screening rates previously reported in the literature . Because of compliance problems with outpatient audiological assessment and because early identification and expedient amplification lead to better academic and language outcomes, routine inpatient audiological screening of postmeningitic children is advocated. Microbiology, 2003 Nov, 149(Pt 11), 3311 - 9 Tetra-amino-acid tandem repeats are involved in HsdS complementation in type IC restriction-modification systems; Adamczyk-Poplawska M et al.; All known type I restriction and modification (R-M) systems of Escherichia coli and Salmonella enterica belong to one of four discrete families: type IA, IB, IC or ID . The classification of type I systems from a wide range of other genera is mainly based on complementation and molecular evidence derived from the comparison of the amino acid similarity of the corresponding subunits . This affiliation was seldom based on the strictest requirement for membership of a family, which depends on relatedness as demonstrated by complementation tests . This paper presents data indicating that the type I NgoAV R-M system from Neisseria gonorrhoeae, despite the very high identity of HsdM and HsdR subunits with members of the type IC family, does not show complementation with E . coli type IC R-M systems . Sequence analysis of the HsdS subunit of several different potential type IC R-M systems shows that the presence of different tetra-amino-acid sequence repeats, e.g . TAEL, LEAT, SEAL, TSEL, is characteristic for type IC R-M systems encoded by distantly related bacteria . The other regions of the HsdS subunits potentially responsible for subunit interaction are also different between a group of distantly related bacteria, but show high similarity within these bacteria . Complementation between the NgoAV R-M system and members of the EcoR124 R-M family can be restored by changing the tetra-amino-acid repeat within the HsdS subunit . The authors propose that the type IC family of R-M systems could consist of several complementation subgroups whose specificity would depend on differences in the conserved regions of the HsdS polypeptide. J Exp Med, 2003 Nov 3, 198(9), 1313 - 22 Down-regulation of CD46 by piliated Neisseria gonorrhoeae; Gill DB et al.; Human membrane cofactor protein (CD46) protects host cells against complement attack and may function as a receptor for pathogenic Neisseriae . We assessed CD46 expression in the human cervical cell line ME-180 after exposure to Neisseria gonorrhoeae . Piliated but not nonpiliated gonococci adhered to cells and produced up to an 80% reduction in CD46 surface expression by 6 h that persisted for at least 24 h . This response required a minimum multiplicity of infection of 10 and was not prevented by antibodies to CD46 . CD46 down-regulation was not attributable to intracellular retention or a global or specific shutdown of mRNA or protein synthesis . Substantial quantities of CD46 were found in the supernatants, indicating a specific shedding of this protein . Adherent gonococci lacking the pilus retraction protein PilT did not down-regulate CD46 but de-repression of pilT expression restored CD46 down-regulation . After experimental infection of human volunteers with a gonococcal variant incapable of inducing CD46 down-regulation, variants of this strain were reisolated that exhibited CD46 down-regulation . Pilus-mediated interactions of gonococci with human epithelial cells results in a pathogen-induced manipulation of the host cell environment in which a membrane protein is removed from epithelial cells by liberation into the surrounding milieu. Ophthalmology, 2003 Nov, 110(11), 2134 - 6 Polymerase chain reaction detection of Neisseria meningitidis in the intraocular fluid of a patient with endogenous endophthalmitis but without associated meningitis; Kerkhoff FT et al.; PURPOSE: To report a patient with Neisseria meningitidis endophthalmitis without associated meningitis with full visual recovery, with early detection of the microorganism using polymerase chain reaction (PCR) analysis . DESIGN: Retrospective, observational case report . PARTICIPANTS: One patient with endogenous endophthalmitis . METHODS: Polymerase chain reaction analysis and culture of the intraocular fluid sample . Polymerase chain reaction analysis was performed with a universal (16S rRNA) primer set to detect bacterial DNA, and subsequently a specific probe was used to detect Neisseria species DNA . RESULTS: The 16S rRNA primers detected bacterial DNA, the specific probe detected Neisseria species DNA, and culture was positive for Neisseria meningitidis serotype C . CONCLUSIONS: A universal bacterial PCR can be very helpful for the diagnosis of endogenous bacterial endophthalmitis at an early stage of the disease. Eur J Obstet Gynecol Reprod Biol, 2003 Dec 10, 111(2), 183 - 8 Planning of empirical antibiotic therapy for women with pelvic inflammatory diseases: a geographical area-specific study; Skapinyecz J et al.; OBJECTIVE: Elaboration of an empiric antibiotic regimen for women with pelvic inflammatory disease (PID) for a geographical area in eastern Hungary . STUDY DESIGN: Pathogens were identified by culturing or polymerase chain reaction (PCR) from 2215 patients with suspected PID between 1 January 1999 and 31 December 2001 . Empiric guidelines for PID treatment were based on susceptibility testing of the recovered bacteria, patient acceptance and cost-effectiveness of drugs and recommendations of earlier studies . RESULTS: Chlamydia trachomatis was detected in 11%, Neisseria gonorrhoeae in 2%, Streptococcus spp . in 17%, Enterococcus spp . 9%, genital mycoplasmas in 25%, all obligate anaerobic pathogens in 30% of the patients . All antibiotics chosen for our regimen were effective in vitro against one or more recovered pathogens at least in 80%; this regimen produced 98% clinical cure rate in mild cases of PID . CONCLUSION: Early detection and prompt empirical antimicrobial therapy adapted to the local microflora and its resistance pattern can lead to good clinical results. FEBS Lett, 2003 Nov 6, 554(1-2), 149 - 53 Molecular and catalytic properties of a peroxiredoxin-glutaredoxin hybrid from Neisseria meningitidis; Rouhier N et al.; A hybrid protein from Neisseria meningitidis, which contains both a peroxiredoxin and a glutaredoxin domain, has been isolated . The enzyme was active in the reduction of various peroxides and dehydroascorbate in the presence of reduced glutathione . These findings suggest that both the peroxiredoxin and glutaredoxin domains are biochemically active in the fusion . Moreover, when expressed separately, the glutaredoxin domain was catalytically active and the peroxiredoxin domain possessed a weak activity when supplemented with exogenous glutaredoxin. Int J STD AIDS, 2003 Oct, 14(10), 681 - 7 The Bali STD/AIDS study: human papillomavirus infection among female sex workers; Ford K et al.; Female sex workers in low priced brothel areas in Denpasar, Bali, Indonesia participated in an intervention study designed to promote condom use and sexually transmitted disease (STD)/AIDS prevention . The intervention provided educational sessions for sex workers, STD treatment for sex workers, condom distribution, and media for clients . The brothel areas were divided into high and low areas for programme effort . The high effort areas received a more intensive behavioural intervention than the low effort areas . A clinic was available for STD treatment in both areas . Behavioural surveys and STD testing were used to evaluate the programmes . About 600 were evaluated for several STDs and completed personal interviews at enrolment and at six-month intervals during the 18-month study . About 50% of women were new to the study at each round . Human papillomavirus (HPV) testing of cervical swabbed specimens, using polymerase chain reaction methodology, was performed at the beginning of the study and 18 months later . Human papillomavirus infection was initially high in these women (38.3%) and declined to 29.7% after 18 months (P <0.01) . The prevalence of HPV infection declined with age (P <0.01) . HPV infection was associated with a number of STD symptoms that were reported in personal interviews . These associations were stronger in the first time period . Infection with Neisseria gonorrhoeae was associated with HPV infection at baseline (P =0.03) . HPV infection declined in the study area with the more intensive educational programme (P <0.01) . The prevalence of HPV infection declined over time and was associated with study area and age of woman. Int J STD AIDS, 2003 Oct, 14(10), 665 - 71 Do STD clinics correctly diagnose STDs? An assessment of STD management in Hefei, China; Liu H et al.; The main purposes of the study were to assess the accuracy of laboratory testing and the diagnosis by physicians in sexually transmitted disease (STD) clinics in Hefei, China . Among 347 men complaining of urethral discharge or dysuria, 240 tested positive at the National Centre for either Neisseria gonorrhoeae or Chlamydia trachomatis, 310 tested positive according to the clinic laboratories, and 347 were diagnosed by the physicians . For chlamydia, the sensitivity and positive predictive value (PPV) of the clinic laboratories were 55% and 26%, and for the diagnosis by the physicians were 61% and 24% . Laboratory testing and the diagnosis by the physicians had low power to detect mixed infection . The PPVs for the diagnosis by the physicians were 50% for syphilis and 43% for herpes simplex virus (HSV), indicating that both syphilis and HSV were over-diagnosed . Over half of those previously infected had not received education to prevent reinfection . Thus, the quality of clinic laboratory testing was not high and physicians often misdiagnosed STDs. Sex Transm Infect, 2003 Oct, 79(5), 399 - 402 Antimicrobial susceptibility of Neisseria gonorrhoeae strains isolated in Guangzhou, China, 1996-2001; Zheng HP et al.; OBJECTIVE: To investigate the in vitro antimicrobial susceptibility and resistant trends of Neisseria gonorrhoeae strains isolated in Guangzhou, from 1996 to 2001 . METHODS: The agar dilution method was used to determine the minimum inhibitory concentrations (MICs) to four antimicrobials, penicillin G, ciprofloxacin, ceftriaxone, and spectinomycin . The resistance of all strains to four antibiotics was interpreted according to criteria used in the project of surveillance of gonococcal antibiotic susceptibility in the WHO Western Pacific Region . Penicillinase producing N gonorrhoeae (PPNG) was analysed by the paper acidometric method . RESULTS: 793 consecutive N gonorrhoeae isolates collected in Guangzhou were studied from 1996 to 2001 . A total of 55 strains of PPNG were identified and the prevalence rapidly spread from 2% to 21.8% . Of the four antibiotics examined, ceftriaxone and spectinomycin appeared to be the most effective agents although two spectinomycin resistant strains were isolated in 1996 . Their MIC(50), MIC(90), and geometric mean MIC (MICmean) were all between the sensitive ranges of the interpretative criteria and remained stable over the years . However, resistance increased continuously to penicillin G and dramatically to ciprofloxacin . In 1996-2001, MIC(50), MIC(90), and MICmean of penicillin G increased from 1 micro g/ml to 2 micro g/ml, 4 micro g/ml to 32 micro g/ml, and 0.68 micro g/ml to 2.35 micro g/ml, respectively; those of ciprofloxacin steeply increased from 0.12 micro g/ml to 4 micro g/ml, 2 micro g/ml to 32 micro g/ml, and 0.14 micro g/ml to 2.62 micro g/ml in 1996-9, respectively, and then declined slightly in 2000-1 . The prevalence of resistant isolates spread from 57.2% to 81.8% for penicillin G and from 17.6% to 72.7% for ciprofloxacin over the 6 years . CONCLUSION: Resistance to penicillin and ciprofloxacin increased greatly during 1996-2001 . Ceftriaxone and spectinomycin should be used as the first line agents in treating gonorrhoea . It is of great importance to continuously survey the susceptibilities of N gonorrhoeae to antibiotics in controlling the spread of gonococcal infections. Sex Transm Infect, 2003 Oct, 79(5), 388 - 92 Sexually transmitted infections in male clients of female sex workers in Benin: risk factors and reassessment of the leucocyte esterase dipstick for screening of urethral infections; Alary M et al.; OBJECTIVES: (1) To assess risk factors for urethral infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among male clients of female sex workers (FSWs) in Benin; (2) to study the validity of LED testing of male urine samples compared to a highly sensitive gold standard (PCR) for the diagnosis of urethral infections with the organisms cited above . METHODS: Male clients of FSWs (n=404) were recruited on site at prostitution venues in Cotonou, Benin, between 28 May and 18 August 1998 . A urine sample was obtained from each participant just before he visited the FSW, and tested immediately using a leucocyte esterase dipstick (LED) test . It was then tested for HIV using the Calypte EIA with western blot confirmation, and for C . trachomatis, N . gonorrhoeae, and T . vaginalis by PCR . After leaving the FSW's room, participants were interviewed about demographics, sexual behaviour, STI history and current symptoms and signs, and were examined for urethral discharge, genital ulcers, and inguinal lymphadenopathies . RESULTS: STI prevalences were: C . trachomatis, 2.7%; N . gonorrhoeae, 5.4%; either chlamydia or gonorrhoea 7.7%; T . vaginalis 2.7%; HIV, 8.4% . Lack of condom use with FSWs and a history of STI were independently associated with C . trachomatis and/or N . gonorrhoeae infection . Over 80% of these infections were in asymptomatic subjects . The overall sensitivity, specificity, positive and negative predictive values of the LED test for detection of either C . trachomatis or N . gonorrhoeae were 48.4%, 94.9%, 44.1%, and 95.7%, respectively . In symptomatic participants (n=22), all these parameters were 100% while they were 47.4%, 94.7%, 37.5%, and 96.4% in asymptomatic men (n=304) . CONCLUSIONS: Since most STIs are asymptomatic in this population, case finding programmes for gonorrhoea and chlamydia could be useful . The performance characteristics of the LED test in this study suggest that it could be useful to detect asymptomatic infection by either C . trachomatis or N . gonorrhoeae in high risk men. Sex Transm Infect, 2003 Oct, 79(5), 363 - 7 Sensitivity requirements for the point of care diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae in women; Vickerman P et al.; BACKGROUND/OBJECTIVES: Most current tests for Neisseria gonorrhoeae and Chlmydia trachomatis require the support of a laboratory, and results are not usually available before the patient has left the clinic . This delay can lead to patients not returning for treatment and may allow further STI transmission to occur . Current rapid point of care (POC) STI tests and the syndromic approach are less sensitive than gold standard tests, but allow treatment at the initial visit . This study estimates the required sensitivity of POC tests that ensures as many STIs are averted as with current gold standard tests . METHODS: A mathematical model is developed to compare the STIs averted using different STI diagnostic methods . Data from Benin, South Africa, Tanzania, and England are used to explore how the required sensitivity differs between settings . RESULTS: The required sensitivity of a POC test is low if there is significant STI transmission during the delay in treatment for the gold standard test and/or few women return for treatment . For example, the required sensitivity of a POC test for C trachomatis is 50% (gold standard test sensitivity is 90%) if either 55% return for treatment and there is no STI transmission, or 80% return for treatment and 50% of infected women infect their partner during the delay in treatment . Furthermore, in these settings a POC test of moderate sensitivity can lead to significantly more STI averted than the gold standard test . CONCLUSIONS: These results support the use of moderate sensitivity POC tests in scenarios where many women will not return for treatment, and in populations where the delay in treatment would result in significant STI transmission. Infect Immun, 2003 Nov, 71(11), 6381 - 91 Gonococcal phospholipase d modulates the expression and function of complement receptor 3 in primary cervical epithelial cells; Edwards JL et al.; CR3-mediated endocytosis is a primary mechanism by which Neisseria gonorrhoeae elicits membrane ruffling and cellular invasion of the cervical epithelia . Our data indicate that, upon infection of cervical epithelia, N . gonorrhoeae specifically releases proteins, including a phospholipase D (PLD) homolog, which facilitate membrane ruffling . To elucidate the function of gonococcal PLD in infection of the cervical epithelia, we constructed an N . gonorrhoeae PLD mutant . By comparative association and/or invasion assays, we demonstrated that PLD mutant gonococci are impaired in their ability to adhere to and to invade primary cervical cells . This defect can be rescued by the addition of supernatants obtained from wild-type-infected cell monolayers but not by exogenously added Streptomyces PLD . The decreased level of total cell association (i.e., adherence and invasion) observed for mutant gonococci is, in part, attributed to the inability of these bacteria to recruit CR3 to the cervical cell surface with extended infection . Using electron microscopy, we demonstrate that gonococcal PLD may be necessary to potentiate membrane ruffling and clustering of gonococci on the cervical cell surface . These data may be indicative of the inability of PLD mutant gonococci to recruit CR3 to the cervical cell surface . Alternatively, in the absence of gonococcal PLD, signal transduction events required for CR3 clustering may not be activated . Collectively, our data indicate that PLD augments CR3-mediated gonococcus invasion of and survival within cervical epithelia. Infect Immun, 2003 Nov, 71(11), 6279 - 91 Low-level pilin expression allows for substantial DNA transformation competence in Neisseria gonorrhoeae; Long CD et al.; The gonococcal pilus is a major virulence factor that has well-established roles in mediating epithelial cell adherence and DNA transformation . Gonococci expressing four gonococcal pilin variants with distinct piliation properties under control of the lac regulatory system were grown in different levels of the inducer isopropyl-beta-D-thiogalactopyranoside (IPTG) . These pilin variants expressed various levels of pilin message and pilin protein in response to the level of IPTG in the growth medium . Moreover, posttranslational modifications of the variant pilin proteins were detected, including S-pilin production and glycosylation . The ratio of the modified and unmodified pilin forms did not substantially change with different levels of pilin expression, showing that these modifications are not linked to pilin expression levels . DNA transformation competence was also influenced by IPTG levels in the growth medium . Substantial increases in transformation competence over an isogenic, nonpiliated mutant were observed when limited amounts of three of the pilin variants were expressed . Immunoelectron microscopy showed that when limited amounts of pilin are expressed, pili are rare and do not explain the pilin-dependent transformation competence . This pilin-dependent transformation competence required prepilin processing, the outer membrane secretin PilQ, and the twitching-motility-regulating protein PilT . These requirements show that a fully functional pilus assembly apparatus is required for DNA uptake when limited pilin is produced . We conclude that the pilus assembly apparatus functions to import DNA into the bacterial cell in a pilin-dependent manner but that extended pili are not required for transformation competence. J Biol Chem, 2004 Jan 2, 279(1), 726 - 34 Epub 2003 Oct 21. Molecular basis of the amylose-like polymer formation catalyzed by Neisseria polysaccharea amylosucrase; Albenne C et al.; Amylosucrase from Neisseria polysaccharea is a remarkable transglucosidase from family 13 of the glycoside-hydrolases that synthesizes an insoluble amylose-like polymer from sucrose in the absence of any primer . Amylosucrase shares strong structural similarities with alpha-amylases . Exactly how this enzyme catalyzes the formation of alpha-1,4-glucan and which structural features are involved in this unique functionality existing in family 13 are important questions still not fully answered . Here, we provide evidence that amylosucrase initializes polymer formation by releasing, through sucrose hydrolysis, a glucose molecule that is subsequently used as the first acceptor molecule . Maltooligosaccharides of increasing size were produced and successively elongated at their nonreducing ends until they reached a critical size and concentration, causing precipitation . The ability of amylosucrase to bind and to elongate maltooligosaccharides is notably due to the presence of key residues at the OB1 acceptor binding site that contribute strongly to the guidance (Arg415, subsite +4) and the correct positioning (Asp394 and Arg446, subsite +1) of acceptor molecules . On the other hand, Arg226 (subsites +2/+3) limits the binding of maltooligosaccharides, resulting in the accumulation of small products (G to G3) in the medium . A remarkable mutant (R226A), activated by the products it forms, was generated . It yields twice as much insoluble glucan as the wild-type enzyme and leads to the production of lower quantities of by-products. Biochem Cell Biol, 2003 Aug, 81(4), 275 - 83 The bacterial receptor protein, transferrin-binding protein B, does not independently facilitate the release of metal ion from human transferrin; Nemish U et al.; Pathogenic Gram-negative bacteria of the Pasteurellaceae and Neisseriaceae acquire iron for growth from host transferrin through the action of specific surface receptors . Iron is removed from transferrin by the receptor at the cell surface and is transported across the outer membrane to the periplasm . A periplasmic binding protein-dependent pathway subsequently transports iron into the cell . The transferrin receptor is composed of a largely surface-exposed lipoprotein, transferrin binding protein B, and a TonB-dependent integral outer membrane protein, transferrin binding protein A . To examine the role of transferrin binding protein B in the iron removal process, complexes of recombinant transferrin binding protein B and transferrin were prepared and compared with transferrin in metal-binding and -removal experiments . A polyhistidine-tagged form of recombinant transferrin binding protein B was able to purify a complex with transferrin that was largely monodisperse by dynamic light scattering analysis . Gallium was used instead of iron in the metal-binding studies, since it resulted in increased stability of recombinant transferrin binding protein B in the complex . Difference absorption spectra were used to monitor removal of gallium by nitrilotriacetic acid . Kinetic and equilibrium binding studies indicated that transferrin binds gallium more tightly in the presence of transferrin binding protein B . Thus, transferrin binding protein B does not facilitate metal ion removal and additional components are required for this process. Di Yi Jun Yi Da Xue Xue Bao, 2003 Oct, 23(10), 1099 - 100 {Resistance of Neisseria gonorrhoeae to 4 antibiotics: an analysis of the situation in Guangzhou in 2002}; Fei S et al.; OBJECTIVE: To survey the antibiotic resistance and the prevalence of penicillinase-producing and highly tetracycline-resistant Neisseria gonorrhoeae (PPNG and TRNG) in Guangzhou in 2002 . METHODS: Minimum inhibitory concentrations (MIC) of the 4 antimicrobial agents, tetracycline, spectinomycin, ciprofloxacin and ceftriaxone, to 100 strains of Neisseria gonorrhoeae were determined by agar dilution method, and beta-lactamase was detected by iodine quantification method . RESULTS: There were 15 (15%) strains of PPNG and 28 (28%) strains of TRNG among the 100 strains of Neisseriae gonorrhoeae examined, with a resistant rate to ciprofloxacin as high as 98% and 32 (32%) strains identified to be highly resistant to the antibiotics (MIC >or=16 mg/L) . No resistant strains to ceftriaxone and specitinomycin were identified, but ceftriaxone susceptibility of the strains was declining . CONCLUSIONS: The current antibiotic resistance of gonococci strains are still serious in Guangzhou, especially in the case of ciprofloxacin resistance . The strains are sensitive to spectinomycin and ceftriaxone, and continuous monitoring of the bacteria for their antibiotic resistance is necessary. J Biol Inorg Chem, 2003 Nov, 8(8), 881 - 92 Epub 2003 Oct 09. Kinetics and mechanism of iron release from the bacterial ferric binding protein nFbp: exogenous anion influence and comparison with mammalian transferrin; Boukhalfa H et al.; Ferric binding protein, Fbp, serves an essential biological function in shuttling naked (hydrated) Fe(3+) across the periplasmic space of many Gram-negative bacteria . In this process, iron must be released at the cytoplasmic membrane to a permease . How iron is released from Fbp has yet to be resolved . Consequently, understanding the dynamics of iron release from Fbp is of both biological and chemical interest . Fbp requires an exogenous anion, e.g . phosphate when isolated from cell lysates, for tight iron sequestration . To address the role of exogenous anion identity and lability on Fe(aq)(3+) dissociation from Fbp, the kinetics of PO(4)(3-) exchange in Fe(3+) nFbp(PO(4)) ( nFbp=recombinant Fbp from Neisseria meningitidis) were investigated by dynamic (31)P NMR and the kinetics of Fe(3+) dissociation from Fe(3+) nFbp(X) (X=PO(4)(3-), citrate anion) were investigated by stopped-flow pH-jump measurements . We justify the use of non-physiological low-pH conditions because a high {H(+)} will drive the Fe(aq)(3+) dissociation reaction to completion without using competing chelators, whose presence may complicate or influence the dissociation mechanism . For perspective, these studies of nFbp (which has been referred to as a bacterial transferrin) are compared to new and previously published kinetic and thermodynamic data for mammalian transferrin . Significantly, we address the lability of the Fe(3+) coordination shell in nFbp, Fe(3+) nFbp(X) (X=PO(4)(3-), citrate), with respect to exogenous anion (X(n-)) exchange and dissociation, and ultimately complete dissociation of the protein to yield naked (hydrated) Fe(aq)(3+) . These findings are a first step in understanding the process of iron donation to the bacterial permease for transport across the cytoplasmic membrane. Pediatr Infect Dis J, 2003 Oct, 22(10 Suppl), S223 - 7 Influenza A community-acquired pneumonia in East London infants and young children; Laundy M et al.; BACKGROUND: Community-acquired pneumonia (CAP) is common in young children, but there are few data in Europe on influenza A virus as a cause of childhood CAP . The aim of this study was to determine the relative contributions of different etiologic agents to CAP in children . METHODS: This was a 6-month prospective study of pediatric accident and emergency and general practice consultations with a diagnosis of CAP . Nasopharyngeal aspirates for viral immunofluorescence and PCR studies and blood cultures for bacterial studies were taken from 51 children with symptoms, signs and chest radiographic features that satisfied a diagnosis of pneumonia . RESULTS: An etiologic agent was isolated from 25 patients (49%) . A viral cause was identified in 22 patients (43%), and influenza A virus and respiratory syncytial virus (RSV) were detected in 16 and 18% of all cases, respectively . Only four patients (8%) had a positive bacterial blood culture; three had Streptococcus pneumoniae and one had Neisseria meningitidis W135 . Mycoplasma pneumoniae was detected in 2 children, and mixed infections were detected in 5 (10%) . The use of viral PCR increased the detection rate of influenza A virus by 100% . CONCLUSION: Influenza A virus caused more than one-third of all viral CAP cases, a rate comparable with that of RSV CAP . Viral PCR doubled the diagnostic yield of influenza A virus . The clinical burden of influenza A CAP was comparable with that of RSV CAP, as measured by the duration of fever, hospital stay and total duration of illness. J Immunol, 2003 Oct 15, 171(8), 4263 - 70 Evidence for naturally acquired T cell-mediated mucosal immunity to Neisseria meningitidis; Davenport V et al.; Naturally acquired protective immunity against Neisseria meningitidis is thought to partially explain the disparity between the high levels of carriage in the human nasopharynx and the rare incidence of disease . To investigate this immunity to Neisseria meningitidis at the mucosal level, in vitro cellular responses to outer membrane vesicle preparations derived from this pathogen were examined using mononuclear cells from the palatine tonsils of adults and children . Characterization of these responses was achieved by depletion of CD45RA(+), CD45RO(+), and CD19(+) populations and outer membrane vesicles derived from isogenic mutants expressing different serosubtypes of the major outer membrane protein, porin A (PorA), no PorA and membrane preparations from a mutant with no LPS (LpxA(-)) . The magnitude of cellular proliferative responses against the outer membrane vesicles were strongly associated with age and were largely T cell mediated, involving both CD45RO(+) and CD45RA(+) T cell phenotypes . Responses were not dependent on LPS but consisted of both PorA cross-specific and non-PorA-dependent responses . Cellular immunity against Neisseria meningitidis was found to be frequently associated with systemic IgG Abs but was not associated with serum bactericidal Abs . For the first time our results demonstrate an age-associated acquisition of mucosal T effector/memory cell responses to Neisseria meningitidis . This mucosal cellular immunity can be present in the absence of serum bactericidal Abs, a classical marker of protective immunity. J Infect Chemother, 2003 Sep, 9(3), 248 - 53 Sexually transmitted diseases in Japanese female commercial sex workers working in massage parlors with cell baths; Miyazaki M et al.; A cross-sectional study of Japanese female commercial sex workers (FCSWs) working in massage parlors with cell baths (MPCBs) was conducted between July 1999 and December 2001 . The study subjects were 171 FCSWs aged from 19 to 36 years . A questionnaire included sexual characteristics in addition to working name and date of birth . We serologically or bacteriologically confirmed the prevalence of HIV-1, HIV-2, hepatitis B virus (HBV), hepatitis C virus (HCV), Chlamydia trachomatis, Neisseria gonorrhoeae, syphilis, and trichomoniasis . There were no differences in the clinical characteristics of FCSWs working in standard-class MPCBs (group A) and those working in expensive-class MPCBs (group B) . With respect to sexual characteristics, HIV-1 and HIV-2 were not confirmed in any subjects, but N . gonorrhoeae was detected in 1.2% . Use of condoms was 98.4% in group A and 83.3% in group B ( P < 0.01) . No HIV infection and an extremely low prevalence of sexually transmitted diseases (STDs) were recognized in Japanese FCSWs working in standard- and expensive-class MPCBs. Int J STD AIDS, 2003 Sep, 14(9), 614 - 21 Sexually transmitted infections prevalence rates in slum communities of Dhaka, Bangladesh; Sabin KM et al.; The study objective was to estimate the prevalence of selected sexually transmitted infections (STIs) and associated factors among Dhaka slum dwellers . Blood and urine specimens were collected from 1534 men and women . Participants in this cross-sectional study responded to a questionnaire, providing socioeconomic data, symptomatology and treatment-seeking behaviour . Specimens were tested for syphilis, hepatitis B (HBsAg), Neisseria gonorrhoeae, Chlamydia trachomatis, and HIV . Serologic evidence of syphilis infection was found in 6.0% of respondents, HBsAg in 3.8% . Prevalence rates of gonorrhoea and chlamydia were 1.7% and <1%, respectively . No HIV infections were found . Men were more than twice as likely as women to be infected with syphilis or HBsAg carriers . Behaviours facilitating STI transmission were common among men . Syphilis infection is prevalent enough to warrant the initiation of screening programmes in this population . The prevalence rate of hepatitis B carriage suggests that this population would benefit from universal vaccination against hepatitis B. Int J STD AIDS, 2003 Sep, 14(9), 609 - 13 High rates of sexually transmitted diseases among male transvestites in Jakarta, Indonesia; Joesoef MR et al.; Many male transvestites (waria) in Jakarta, Indonesia engage in unprotected receptive anal and oral intercourse with homosexual and bisexual men for pay . Although this behaviour clearly puts them at risk of sexually transmitted diseases (STDs), including HIV infection, little is known about the prevalence of STD among them . To learn the STD prevalence and its risk factors, we conducted an STD prevalence survey among waria in North Jakarta, Indonesia . From August to December 1999 we offered screening for rectal and pharyngeal infections with Neisseria gonorrhoeae (Ng), Chlamydia trachomatis (Ct) by DNA probe (GenProbe PACE 2) and for Treponema pallidum (Tp) by non-treponemal and treponemal serological tests . Of 296 participants (median age 28 years), 93% reported having been paid for sex . A total of 96% reported having had oral sex (median five times/week) and/or anal sex (median three times/week) in the last week . Ng was found in the rectum of 12.8% and the pharynx of 4.2%; Ct was found in 3.8% and 2.4%, respectively . A total of 43.6% had reactive non-treponemal and treponemal tests . Of the 129 with positive treponemal tests, 42.6% had non-treponemal test titres greater than 1:8 . In the logistic regression model, waria who were younger (< or =25 years old) had a significantly 3.5 times risk of Ng and/or Ct infections than older waria (>25 years old) . Because only 12% of waria stated that they consistently used condoms during any sex act, it is important to warn them that STD/HIV transmission can occur with either anal or oral sex and that the risk of either anal or oral transmission can be reduced by condom use . In addition, high rates of asymptomatic syphilis and rectal gonorrhoea warrant a periodic screening and treatment for these infections in this population . Because waria have the highest rates of HIV and their clients consist of homosexual and bisexual men, successful prevention efforts in waria could help curb the spread of the epidemic. Afr J Med Med Sci, 2001 Sep, 30(3), 199 - 205 Reproductive health needs of young persons in markets and motor parks in south west Nigeria; Dare OO et al.; The aim of the study was to assess the reproductive health needs of out-of-school males and females aged 12-26 years working in markets and motor parks in Ibadan using Focus Group Discussions (FGD) and a survey questionnaire . Result revealed that sexual experience was higher among males (80%) compared to females (66%) . Multiple concurrent sexual partnerships were found to be common among unmarried young men (71%) than women (51%) but means to prevent pregnancy or sexually transmitted disease (STD) were rarely employed . The knowledge of HIV was high (70%) though very few (12%) were aware that an infected individual would remain asymtomatic . Moreover, 36.5% thought that condoms make sex less enjoyable . Between 6 and 9% used a method for disease prevention within marriage or regular partnerships compared to 16% in casual contacts . Despite high exposure to risk, the prevalence of STDs was low as only 4% of the sexually experienced males and 9% of females were infected with Candida Albicans, Chlamydia trachomatis and Trichomonas vaginitis or Neisseria gonorrhea . The ready availability of antibiotics may account for this apparent discrepancy . These findings suggest that out of school adolescents working in motor parks needs sexuality education and counseling backed up with clinical services. Afr J Med Med Sci, 2001 Dec, 30(4), 281 - 3 Non-penicillinase producing Neisseria gonnorhoeae: are they still in existence in Ibadan, Nigeria? Bakare RA, Oni AA, Umar US, Kehinde AO, Fayemiwo SA, Alli OO. In an attempt to evaluate the current prevalence rate of penicillinase producing Neisseria gonorrhoeae (PPNG) and whether non-PPNG strains are still in existence in Ibadan, Nigeria, all isolates of Neisseria gonorrhoeae from patients that attended our clinic between January and December 1997 were studied . Of the 155 patients that had gonococcal infections, 118 were male (76.1%) and 37 (23.9%) were female with 31 (83.8%) being the partners of infected men . Sixty-four (54.2%) of the male and 19 (51.4%) of the female were aged between 20 and29 years while 21.2% of the male and 16.2% of the female were in the age of 40 and above . The sex difference is not statistically significant (chi2=1.47,P=-0.69) . The present study revealed that non-PPNG strains have reduced considerably to 5.4% from 100% in 1977 . This has posed a great threat to the usefulness of penicillin and ampicillin as the drugs of choice in gonococcal therapy in Nigeria. Commun Dis Intell, 2003, 27(3), 373 - 9 An assessment of the Roche Amplicor Chlamydia trachomatis/Neisseria gonorrhoeae multiplex PCR assay in routine diagnostic use on a variety of specimen types; Leslie DE et al.; The Roche Cobas Amplicor Chlamydia trachomatis/Neisseria gonorrhoeae polymerase chain reaction (PCR) assay can simultaneously detect both C . trachomatis and N . gonorrhoeae, and has been cleared by United States Food and Drug Administration (FDA) for the testing of endocervical and urethral swabs and urine specimens . The Amplicor N . gonorrhoeae PCR target sequence is known to be present in some strains of commensal Neisseria species, including N . cinerea and N . subflava, necessitating the use of a second PCR assay to confirm positive results . This study analyses the performance of the assay on 7,007 unselected specimens submitted to the laboratory for the PCR diagnosis of N . gonorrhoeae and C . trachomatis; compares the PCR assay with culture for the detection of N . gonorrhoeae; examines the performance of the assay with specimens from different body sites; and briefly compares two confirmatory PCR assays . Confirmation rates for an initial Amplicor N . gonorrhoeae positive result varied widely by specimen type, ranging from 86.2 per cent for penile/urethral swabs to 5.6 per cent for oropharyngeal swabs, indicating all positive Amplicor N . gonorrhoeae results should be confirmed by a second method to maintain adequate specificity . Overall there was 98.1 per cent agreement between the confirmed PCR assay and culture, with confirmed PCR showing a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 81.7 per cent, 99.5 per cent, 92.7 per cent and 98.5 per cent respectively, compared with N . gonorrhoeae culture . When confirmed C . trachomatis/N . gonorrhoeae PCR assay performance was analysed against culture using only FDA-cleared specimens (553 penile/ urethral swabs, urines and cervical/vaginal swabs), sensitivity, specificity, PPV and NPV and percent agreement were 96.7 per cent, 99.8 per cent, 98.9 per cent, 99.4 per cent and 99.3 per cent respectively . No significant differences were found between the two confirmatory PCR assays used during the study period . Limitations of Amplicor for the detection of N . gonorrhoeae and the appropriate use of combined C . trachomatis/N . gonorrhoeae PCR in a routine diagnostic setting are discussed. Mol Microbiol, 2003 Oct, 50(1), 245 - 57 Experimentally revised repertoire of putative contingency loci in Neisseria meningitidis strain MC58: evidence for a novel mechanism of phase variation; Martin P et al.; Analysis of the genome sequence of Neisseria meningitidis strain MC58 revealed 65 genes associated with simple sequence repeats . Experimental evidence of phase variation exists for only 14 of these 65 putatively phase variable genes . We investigated the phase variable potential of the remaining 51 genes . The repeat tract associated with 20 of these 51 genes was sequenced in 26 genetically distinct strains . This analysis provided circumstantial evidence for or against the phase variability of the candidate genes, based on the sequence and the length of the repeated motif . These predictions of phase variability were substantiated for three of these candidate genes using colony immunoblotting or beta-galactosidase as a reporter . This investigation identified a novel phase variable gene (NMB1994 or nadA) associated with a repeat tract (TAAA) not previously reported to be associated with phase variable genes in N . meningitidis . Analysis of the nadA transcript revealed that the repeat tract was located upstream of the putative -35 element of the nadA promoter . Semiquantitative RT-PCR showed that variation in the number of repeats was associated with changes in the level of expression of nadA, findings consistent with a model whereby the variable number of (TAAA) repeats modulates the promoter strength. Mol Microbiol, 2003 Oct, 50(1), 3 - 13 Recombination, repair and replication in the pathogenic Neisseriae: the 3 R's of molecular genetics of two human-specific bacterial pathogens; Kline KA et al.; Most of the detailed mechanisms that have been established for the molecular biological processes that mediate recombination, repair and replication of DNA have come from studies of the Escherichia coli paradigm . The human specific pathogens, Neisseria gonorrhoeae and N . meningitidis, are Gram-negative bacteria that have some molecular processes that are similar to E . coli and others that appear to be divergent . We propose that the pathogenic Neisseriae have evolved a specialized collection of molecular mechanisms to adapt to life limited to human hosts . In this MicroReview, we explore what is known about the basic processes of DNA repair, DNA recombination (genetic exchange and pilin variation) and DNA replication in these human specific pathogens. Antimicrob Agents Chemother, 2003 Oct, 47(10), 3336 - 8 PCR and restriction endonuclease assay for detection of a novel mutation associated with sulfonamide resistance in Neisseria meningitidis; Bennett DE et al.; We identified a previously undocumented mutation in the dihydropteroate synthase (folP) gene associated with Neisseria meningitidis sulfonamide resistance . A PCR-based assay to detect this mutation, which is 100% predictive of sulfonamide resistance, was developed. Spinal Cord, 2003 Oct, 41(10), 590 - 1 Infective discitis with Neisseria sicca/subflava in a previously healthy adult; Roberts PJ et al.; STUDY DESIGN: A case report of Neisseria sicca/subflava discitis in a healthy elderly female . OBJECTIVE: To report a rare case, which is usually seen exclusively in children . SETTING: Stoke on Trent, England . METHOD: Case report, a 65-year-old female with a 6 month history of back and bilateral leg pain . X-rays showed collapse of L4/5 disc . No neurological deficit . Magnetic resonance imaging supported the clinical suspicion of discitis . Percutaneous biopsy followed 2 weeks later by open biopsy with bilateral root decompression was performed . Culture of L4/5 disc tissue produced Neisseria sicca/subflava . The patient was treated with a 4-week course of intravenous amoxycillin . Follow-up at 3 months confirmed clinical resolution of original symptoms . CONCLUSION: Any organism cultured from biopsy needs to be interpreted within the context of the clinical case . If clinical suspicion is high, further weight must be added to the finding of unusual or environmental organisms and culture of a repeat aspirate or biopsy may clarify the significance. Infect Immun, 2003 Oct, 71(10), 6019 - 26 Streptococcus pyogenes infection induces septic arthritis with increased production of the receptor activator of the NF-kappaB ligand; Sakurai A et al.; Bacterial arthritis is a rapidly progressive and highly destructive joint disease in humans, with Staphylococcus aureus and Neisseria gonorrhoeae the major causative agents, although beta-hemolytic streptococci as well often induce the disease . We demonstrate here that intravenous inoculation of CD-1 mice with the group A streptococcus (GAS) species Streptococcus pyogenes resulted in a high incidence of septic arthritis . Signs of arthritis emerged within the first few days after injection, and bacterial examinations revealed that colonization of the inoculated GAS in the arthritic joints persisted for 21 days . Induction of persistent septic arthritis was dependent on the number of microorganisms inoculated . Immunohistochemical staining of GAS with anti-GAS antibodies revealed colonization in the joints of infected mice . Cytokine levels were quantified in the joints and sera of infected mice by using an enzyme-linked immunosorbent assay . High levels of interleukin-1beta (IL-1beta) and IL-6 were detected in the joints from 3 to 20 days after infection . We noted that an increase in the amount of receptor activator of NF-kappaB ligand (RANKL), which is a key cytokine in osteoclastogenesis, was also evident in the joints of the infected mice . RANKL was not detected in sera, indicating local production of RANKL in the infected joints . Blocking of RANKL by osteoprotegerin, a decoy receptor of RANKL, prevented bone destruction in the infected joints . These results suggest that GAS can colonize in the joints and induce bacterial arthritis . Local RANKL production in the infected joints may be involved in bone destruction. Infect Immun, 2003 Oct, 71(10), 5576 - 82 A gonococcal efflux pump system enhances bacterial survival in a female mouse model of genital tract infection; Jerse AE et al.; Active efflux of antimicrobial substances is likely to be an important bacterial defense against inhibitory host factors inherent to different body sites . Two well-characterized multidrug resistance efflux systems (MtrCDE and FarAB-MtrE) exist in Neisseria gonorrhoeae, a bacterial pathogen of the human genital mucosae . In vitro studies suggest that the MtrCDE and FarAB-MtrE efflux systems protect the gonococcus from hydrophobic antimicrobial substances that are likely to be present on mucosal surfaces . Here we report that a functional MtrCDE efflux system, but not a functional FarAB-MtrE system, enhances experimental gonococcal genital tract infection in female mice . Specifically, the recovery of mtrD and mtrE mutants, but not a farB mutant, from mice inoculated with mutant or wild-type gonococci was reduced compared with that of the wild-type strain . Competitive-infection experiments confirmed the survival disadvantage of MtrCDE-deficient gonococci . This report is the first direct evidence that a multidrug resistance efflux system enhances survival of a bacterial pathogen in the genital tract . Additionally, experiments using ovariectomized mice showed that MtrCDE-deficient gonococci were more rapidly cleared from mice that were capable of secreting gonadal hormones . MtrCDE-deficient gonococci were more sensitive to nonphysiological concentrations of progesterone in vitro than were wild-type or FarAB-MtrE-deficient gonococci . These results suggest that progesterone may play an inhibitory role in vivo . However, hormonally regulated factors rather than progesterone itself may be responsible for the more rapid clearance of mtr-deficient gonococci from intact mice. Biochem J, 2003 Nov 15, 376(Pt 1), 35 - 41 Oxo-iron clusters in a bacterial iron-trafficking protein: new roles for a conserved motif; Zhu H et al.; We report a set of three 1.8-1.9 A resolution X-ray crystal structures of Neisseria gonorrhoeae Fbp (ferric-ion binding protein): (i) open-cleft apo-Fbp containing bound phosphate, (ii) open-cleft mono-Fe Fbp capped by nitrilotriacetate, and (iii) open-cleft trinuclear oxo-iron Fbp, the first structure of an iron-cluster adduct of a transferrin . The nine independent molecules in the unit cells provide 'snapshots' of the versatile dynamic structural roles of the conserved dityrosyl iron-binding motif (Tyr195-Tyr196) which control the capture and, possibly, processing of iron . These findings have implications for understanding bacterial iron acquisition and dissimilation, and organic/mineral interfaces. Sex Transm Dis, 2003 Sep, 30(9), 671 - 9 Sexually transmitted infections among female sex workers in Kupang, Indonesia: searching for a screening algorithm to detect cervical gonococcal and chlamydial infections; Davies SC et al.; BACKGROUND AND GOAL: Notifications of HIV infection in Indonesia are increasing, but there are few data on other sexually transmitted infections (STIs), especially in the eastern islands of Indonesia . We aimed to measure the prevalence of STIs among female sex workers (FSWs) in Kupang, West Timor, and to develop screening algorithms to detect cervical infections with Neisseria gonorrhoeae and/or Chlamydia trachomatis (NG/CT) . STUDY DESIGN: During 6 months in 1999, we recruited all the FSWs at Kupang's only brothel complex and a smaller number of independent FSWs . The women were examined at dedicated clinics and most laboratory tests were performed at provincial laboratories . Algorithms based on the strongest associations of variables with NG/CT were compared with the laboratory diagnoses . RESULTS: We recruited 288 women . The prevalence of N gonorrhoeae infection was 31%, that of C trachomatis infection was 24%, that of Trichomonas vaginalis infection was 5%, and that of syphilis was 13% . No case of HIV infection was detected . Few women had symptoms of STI . The only variables significantly associated with NG/CT after logistic regression analysis were the presence of cervical discharge (either yellow or clear) and a high count of polymorphonuclear leukocytes on gram-stained endocervical smear . Several algorithms to screen for NG/CT achieved high (>80%) sensitivity, but the highest specificity among these was only 50% . CONCLUSIONS: Although several of the generated algorithms may be useful in the absence of simple, accurate, affordable diagnostic tests, the high rates of STIs in this population could justify a more aggressive strategy incorporating periodic presumptive treatment to rapidly reduce prevalence. J Med Microbiol, 2003 Oct, 52(Pt 10), 853 - 9 Comparison of Moraxella catarrhalis isolates from children and adults for growth on modified New York City medium and potential virulence factors; El-Ahmer OR et al.; Initial studies found that Moraxella catarrhalis isolates from adults that grew on modified New York City medium (MNYC(+)) that contained antibiotics selective for pathogenic neisseriae differed from strains that did not grow on this medium (MNYC(-)) in their potential virulence properties . It was predicted that higher usage of antibiotics to treat respiratory illness in children might result in higher proportions of MNYC(+) isolates if antibiotics were an important selective pressure for this phenotype . Two of 100 adult isolates (2 %) were MNYC(+), compared to 88 of 88 isolates (100 %) from children (P = 0.000) . MNYC(+) strains were serum-resistant and bound in higher numbers to HEp-2 cells that were infected with respiratory syncytial virus (RSV) . Endotoxin from an MNYC(+) isolate induced significantly higher pro-inflammatory response levels than endotoxin from an MNYC(-) strain . MNYC(-) adult isolates expressed haemagglutinins and bound in lower numbers to RSV-infected cells, but serum resistance was variable . All isolates from children were MNYC(+), serum-resistant and bound in greater numbers to RSV-infected cells . These results indicate that both RSV infection and antibiotic usage select for the MNYC(+) phenotype. Southeast Asian J Trop Med Public Health, 2003 Jun, 34(2), 367 - 73 Prevalence of lower genital tract infection among women attending maternal and child health and family planning clinics in Hanoi, Vietnam; Anh PK et al.; To determine the prevalence of lower genital tract infection (LGTI) with Candida spp, Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, and bacterial vaginosis among symptomatic and asymptomatic women attending maternal and child health and family planning (MCH/FP) clinics in Hanoi, Vietnam . A multi-centered, cross-sectional descriptive study stratified by reported symptoms of vaginal discharge was carried out in three MCH/FP clinics among 1,000 women aged 18-44 years in 1998 . Of these, 89.1% lived in Hanoi, 97.6% were currently married, and 99.2% had only one sexual partner in the past 12 months . Regarding their contraceptive use, 28.2% did not use any contraception, 25.6% used an intrauterine device (IUD), 22.8% used condoms, and 23.4% used other methods . The overall prevalence of Candida spp was 11.1% (95% CI = 9.1-13.1%); T . vaginalis, 1.3% (95% CI = 0.6-2.0%); no gonococcal infection was found; the prevalence of C . trachomatis was 4.4% (95% CI = 3.1-5.7%); and of bacterial vaginosis, 3.5% (95% CI = 2.4-4.6%) . The presence of LGTI was not associated with reported symptom of vaginal discharge . LGTI was common among married and monogamous women attending MCH/FP clinics in Hanoi, of whom many used IUDs and may have an increased risk of complications in the presence of LGTI . The lack of association between symptoms and laboratory-confirmed infection underscores the challenge of diagnosing LGTI when laboratory testing is not available. Am J Ophthalmol, 2003 Sep, 136(3), 554 - 5 Post traumatic polymicrobial endophthalmitis, including Neisseria subflava; Sharma S et al.; DESIGN: To report the second known case of post-traumatic endophthalmitis caused by Neisseria subflava . DESIGN: Interventional case report . METHODS: A two-year-old child with post-traumatic corneal laceration and uveal prolapse required medical and surgical therapy for endophthalmitis caused by multiple organisms including N . subflava . RESULTS: After aggressive therapy, patient had a favorable outcome without vision compromise . CONCLUSIONS: As there is still not a standard protocol for therapy for post-traumatic endopthalmitis, we recommend the use of broad-spectrum antibiotics via intravitreal, intravenous, and topical routes . Consideration of typical and unusual bacteria that have been reported to cause endopthalmitis, as well as the source of injury, should guide antibiotic choice. Ned Tijdschr Geneeskd, 2003 Aug 23, 147(34), 1621 - 4 {Transient cardiac failure due to infectious myocarditis}; Blom JR et al.; Two men aged 19 (patient A) and 37 (patient B) years respectively, presented with symptoms of general malaise, fever and nonspecific ECG abnormalities . After admission both patients developed shock . Cardiac ultrasound revealed severe left ventricle dysfunction . On the basis of these findings, infectious myocarditis was suspected . Patient B was placed on artificial ventilation and haemodialysis due to respiratory and renal failure . Both patients were treated with inotropic drugs and antibiotics . Neisseria meningitidis was established as the cause of the myocarditis in patient A but in patient B no cause was found despite microbiological and autoimmune investigations . PCR tests and a biopsy of the myocardium were not performed . There was a satisfactory recovery in the left ventricle function of both patients during admission . These two cases illustrate that (infectious) myocarditis should be suspected in patients presenting with symptoms of general malaise, fever and nonspecific ECG abnormalities . If (infectious) myocarditis is diagnosed, the patient should be monitored for severe heart failure. J Biol Chem, 2003 Nov 21, 278(47), 46252 - 60 Epub 2003 Sep 09. The Lip lipoprotein from Neisseria gonorrhoeae stimulates cytokine release and NF-kappaB activation in epithelial cells in a Toll-like receptor 2-dependent manner; Fisette PL et al.; The human pathogen Neisseria gonorrhoeae produces an array of diseases ranging from urethritis to disseminated gonococcal infections . Early events in the establishment of infection involve interactions between N . gonorrhoeae and the mucosal epithelium, which leads to the local release of inflammatory mediators . Because of this, it is important to identify the bacterial virulence factors and host cell components that contribute to inflammation . Using a series of column chromatography steps, we purified a lipoprotein from N . gonorrhoeae strain F62 called Lip . This outer membrane antigen expresses a conserved epitope known as H.8, which is common to all pathogenic Neisseria species . We found the purified preparation of Lip to be a potent inflammatory mediator capable of inducing the release of the chemokine interleukin (IL)-8 and the cytokine IL-6 by immortalized human endocervical epithelial cells and the production of IL-8 and the activation of the transcription factor NF-kappaB by human embryonic kidney 293 (HEK) cells transfected with toll-like receptor (TLR) 2 . Upon removal of Lip by immunoprecipitation, the ability of the H.8/Lip preparation to stimulate NF-kappaB activation was abolished . In addition to TLR2, the activation of NF-kappaB by H.8/Lip in HEK cells was enhanced upon coexpression of TLR1 but not TLR6 . These observations provide evidence that Lip is capable of inducing the release of inflammatory mediators from epithelial cells in a TLR2-dependent manner. J Clin Microbiol, 2003 Sep, 41(9), 4395 - 9 Comparing first-void urine specimens, self-collected vaginal swabs, and endocervical specimens to detect Chlamydia trachomatis and Neisseria gonorrhoeae by a nucleic acid amplification test; Shafer MA et al.; We set out to determine the prevalences of Chlamydia trachomatis and Neisseria gonorrhoeae by ligase chain reaction as well as to determine the prevalence of Trichomonas vaginalis by culture in a large and diverse national sample of non-health-care-seeking young women entering the military; we also sought to compare the abilities of three different techniques of collecting specimens (first-void urine, self-collected vaginal swab, and clinician-collected endocervical swab) to identify a positive specimen . A cross-sectional sample of young women was voluntarily recruited; as a part of their routine entry pelvic examination visit, they completed a self-administered reproductive health questionnaire and provided first-void urine (used to detect C . trachomatis and N . gonorrhoeae) and self-collected vaginal swabs (used to detect C . trachomatis, N . gonorrhoeae, and T . vaginalis) . The number of positive tests divided by the number of sexually active women screened by each sampling method determined the rates of prevalence . The rate of infection with any of the three sexually transmitted diseases (STDs) tested was 14.1% . The total positive rates for each STD (identified by >/=1 specimen) were the following: for C . trachomatis, 11.6%; N . gonorrhoeae, 2.4%; and T . vaginalis, 1.7% . The proportions of positives identified by specimen type were, for C . trachomatis and N . gonorrhoeae, respectively, endocervix, 65 and 40%; urine, 72 and 24%; and vagina, 81 and 72% . The proportions of positives when specimen results were combined were, for C . trachomatis and N . gonorrhoeae, respectively, cervix plus urine, 86 and 49%; cervix plus vagina, 91 and 93%; and vagina plus urine, 94 and 79% . We concluded that STDs were epidemic in this population . Self-collected vaginal swabs identified the highest number of positive test results among single specimens, with the combined cervix-vagina results identifying the highest number of positive results . Self-collected vaginal swab collections are a feasible alternative to cervical specimen collections in this population, and the use of multiple types of specimens increases the positive yield markedly. J Clin Microbiol, 2003 Sep, 41(9), 4141 - 7 Comparison of serologic and genetic porB-based typing of Neisseria gonorrhoeae: consequences for future characterization; Unemo M et al.; Due to temporal changes in the epidemiology of gonorrhea, a precise characterization of Neisseria gonorrhoeae is essential . In the present study genetic heterogeneity in the porB genes of N . gonorrhoeae was examined, and serovar determination was compared to porB gene sequencing . Among 108 N . gonorrhoeae isolates, phylogenetic analysis of the entire porB alleles (924 to 993 bp) identified 87 unique sequences . By analyzing only the four to six most heterogeneous porB gene regions (174 to 363 bp), 86 out of these 87 genetic variants were identified . Consequently, analysis of shorter highly variable regions of the porB gene generates high-level discriminatory ability as well as fast, objective, reproducible, and portable data for epidemiological characterization of N . gonorrhoeae . Regarding putative antigenic epitopes of PorB for Genetic Systems monoclonal antibodies (MAbs), some of the previous findings were confirmed, but new findings were also observed . For several of the MAbs, however, the precise amino acid residues of PorB critical for single-MAb reactivity were difficult to identify . In addition, repeated serovar determination of 108 N . gonorrhoeae isolates revealed discrepancies for 34 isolates, mostly due to nonreproducible reactivity with single MAbs . Thus, the prospects of a genetic typing system with congruent translation of the serovar determination seem to be limited . In conclusion, analysis of short highly variable regions of the porB gene could form the basis for a fast molecular epidemiological tool for the examination of emergence and transmission of N . gonorrhoeae strains within the community. Front Biosci, 2003 Sep 01, 8, d1186 - 218 Mechanisms of iron acquisition by the human pathogens Neisseria meningitidis and Neisseria gonorrhoeae; Rohde KH et al.; It is well established that bacterial pathogenesis is dependent on the ability to acquire iron within the host . The success of the highly adapted obligate human pathogens Neisseria meningitidis (NM) and Neisseria gonorrhoeae (NG) can be attributed in part to the efficient utilization of multiple host iron (Fe) sources, allowing replication on mucosal surfaces, in the bloodstream, and intracellularly . Most Gram-negative bacterial strategies for scavenging iron from the human host rely on the TonB protein to energize active iron transport across the outer membrane . Pathogenic Neisseria express multiple high-affinity iron transporters including a family of two-component TonB-dependent receptors as well as multiple single-component TonB-dependent Fe transporters . This review describes our current understanding of the mechanisms Neisseria have evolved to utilize various iron sources encountered during infection of the human host . Recent studies have provided insight into the interaction of neisserial outer membrane receptors with host iron carrier proteins . Emerging structural information on neisserial iron transporters will be compared with the crystal structures and biochemical data available for homologous Escherichia coli TonB-dependent Fe-siderophore receptors . In the process, we will highlight the aspects of the iron transport process that are unique and those that remain to be experimentally demonstrated in Neisseria . These include receptor structure/function, the mechanism of iron removal from protein ligands, the fate of Fe and heme-Fe after traversing the outer membrane, and the role of TonB-associated energy in receptor functions . Finally, we will discuss regulatory mechanisms that control the expression of iron scavenging systems . The investigation of iron metabolism in NM and NG is important for understanding the biochemistry of this virulence factor, the development of vaccines targeted at outer membrane iron receptors, and therapeutic interventions exploiting these transporters as high affinity drug delivery systems. Clin Infect Dis, 2003 Sep 15, 37(6), 849 - 52 Epub 2003 Aug 28. Multidrug-resistant Neisseria gonorrhoeae with decreased susceptibility to cefixime-Hawaii, 2001; Wang SA et al.; We report 4 urogenital Neisseria gonorrhoeae isolates recovered from 3 patients that demonstrated resistance to penicillin, tetracycline, and ciprofloxacin and reduced susceptibility to cefixime . This report of the first 3 patients in the United States identified with this multidrug-resistant strain may portend an emerging problem for clinicians and public health officials. J Biol Chem, 2003 Nov 14, 278(46), 45352 - 7 Epub 2003 Sep 03. Kinetic characterization of the chemical steps involved in the catalytic mechanism of methionine sulfoxide reductase A from Neisseria meningitidis; Antoine M et al.; Oxidation of methionine into methionine sulfoxide is associated with many pathologies and is described to exert regulatory effects on protein functions . Two classes of methionine sulfoxide reductases, called MsrA and MsrB, have been described to reduce the S and the R isomers of the sulfoxide of methionine sulfoxide back to methionine, respectively . Although MsrAs and MsrBs display quite different x-ray structures, they share a similar, new catalytic mechanism that proceeds via the sulfenic acid chemistry and that includes at least three chemical steps with 1) the formation of a sulfenic acid intermediate and the concomitant release of methionine; 2) the formation of an intra-disulfide bond; and 3) the reduction of the disulfide bond by thioredoxin . In the present study, it is shown that for the Neisseria meningitidis MsrA, 1) the rate-limiting step is associated with the reduction of the Cys-51/Cys-198 disulfide MsrA bond by thioredoxin; 2) the formation of the sulfenic acid intermediate is very efficient, thus suggesting catalytic assistance via amino acids of the active site; 3) the rate-determining step in the formation of the Cys-51/Cys-198 disulfide bond is that leading to the formation of the sulfenic intermediate on Cys-51; and 4) the apparent affinity constant for methionine sulfoxide in the methionine sulfoxide reductase step is 80-fold higher than the Km value determined under steady-state conditions. FEMS Microbiol Lett, 2003 Aug 29, 225(2), 279 - 84 Molecular cloning and characterization of a 79-kDa iron-repressible outer-membrane protein of Moraxella bovis; Kakuda T et al.; Moraxella bovis expresses an iron-repressible 79-kDa outer-membrane protein, IrpA . DNA and N-terminal amino acid sequence analysis indicate that IrpA is closely related to FrpB of Neisseria meningitidis, FetA of Neisseria gonorrhoeae and CopB of Moraxella catarrhalis . The results of manganese mutagenesis and a gel-shift assay suggested that the transcription of irpA is negatively regulated by the ferric uptake regulator . The insertion of an antibiotic resistance cassette into the irpA gene affected the strain's ability to utilize bovine transferrin and lactoferrin . IrpA was detected in geographically diverse clinical isolates, and the antigenicity of IrpA was conserved in all the isolates tested . Therefore, IrpA may have potential as a candidate vaccine. J Bacteriol, 2003 Sep, 185(18), 5585 - 90 Autotransporters as scaffolds for novel bacterial adhesins: surface properties of Escherichia coli cells displaying Jun/Fos dimerization domains; Veiga E et al.; Hybrid proteins containing the beta-autotransporter domain of the immunoglobulin A (IgA) protease of Neisseria gonorrhoea (IgA beta) and the partner leucine zippers of the eukaryotic transcriptional factors Fos and Jun were expressed in Escherichia coli . Such fusion proteins targeted the leucine zipper modules to the cell surface . Cells displaying the Jun beta sequence flocculated shortly after induction of the hybrid protein . E . coli cells expressing separately Fos beta and Junbeta chimeras formed stable bacterial consortia . These associations were physically held by tight intercell ties caused by the protein-protein interactions of matching dimerization domains . The role of autotransporters in the emergence of new adhesins is discussed. Biologicals, 2003 Sep, 31(3), 209 - 12 Validation of colorimetric assay to detect complement-mediated antibody-dependent bactericidal activity against serogroups B and C Neisseria meningitidis; Rodriguez T et al.; Colorimetric serum bactericidal assay (cSBA), based on the addition of glucose and a pH indicator to the culture medium after the bactericidal reaction, was validated . The precision measured as repeatability, intermediated precision, and reproducibility was determined as a percentage in titer coincidence between replicas >/=50 . Moreover the use of the freeze-dried complement was evaluated in comparison to the traditionally stored by freezing . The results were the following: precision: titer +/-1 two-fold dilution (except for the highly positive serum against serogroup B, where there was titer +/-2 dilutions) percentage in titer coincidence: >/=50 . The known titer or +/-1 two-fold dilution was found in the sera titrated with the complement either frozen or freeze-dried . Concluding, cSBA showed to be highly precise, allowing also the use of freeze-dried complement which is another important advantage for this kind of assay. Hunan Yi Ke Da Xue Xue Bao, 2003 Feb 28, 28(1), 53 - 5 {Antibiotic susceptibility of Neisseria gonorrhoeae epidemic strains in Changsha}; Zou MX et al.; OBJECTIVE: To evaluate the antibiotic susceptibility of Neisseria gonorrhoeae epidemic strains in Changsha and to provide a reference for the prevention and treatment of gonorrhea . METHODS: beta-Lactamase was determined by a modified iodometric method and the susceptibility to 9 antibiotic agents was tested by the disc diffusion method in 86 isolates . RESULTS: Plasmid-mediated penicillinase-producing Neisseria gonorrhoeae and plasmid-mediated tetracycline-resistant Neisseria gonorrhoeae were 40.69% and 23.26%, respectively . Of all the 9 antibiotic agents, tetracycline, cefmetazole, penicillin, ciprofloxacin, and ofloxacin had a higher resistance and the percentages of resistance were 45.35%, 50.00%, 62.79%, 77.91%, and 87.21%, respectively . On the other hand, cefuroxime, ceftriaxone, cefepime, and spectinomycin had a higher susceptibility and the percentages of susceptibility were 77.91%, 80.23%, 86.05%, and 98.84%, respectively . CONCLUSION: Penicillin, tetracycline and fluoroquinolone can not be used as routine agents to cure gonorrhea; and spectinomycin can be used as primary medicine to cure gonorrhea in Changsha, but clinical doctors need to pay more attention to it because resistant strains have come into existence. Hunan Yi Ke Da Xue Xue Bao, 2003 Apr, 28(2), 177 - 9 {Infectious distribution and resistant of Neisseria gonorrhoeae, Mycoplasma, and Chlamydia trachomatis in the chronic prostatitis}; Cao W et al.; OBJECTIVE: To investigate the infectious distribution and resistant of Neisseria gonorrhoeae, Mycoplasma, and Chlamydia trachomatis in the chronic prostatitis . METHODS: The identification and susceptibility of Neisseria gonorrhoeaes and Mycoplasmas were detected by a cultural method . The nitrocefin test was used to detect the beta-lactamase in Neisseria gonorrhoeae strains . Chlamydia trachomatis was identificated by a monoclonal gold labeled antibody method . RESULTS: A total of 2,900 prostatic fluids were detected and the rates of isolation of Neisseria gonorrhoeae, Mycoplasma, and Chlamydia trachomatis were 3.3%, 12.8%, and 0.9%, respectively . The prevalence of beta-lactamase in Neisseria gonorrhoeae strains was 12.6% . The resistant percentages of Neisseria gonorrhoeae strains were 73.7% to penicillin and 91.6% to ciprofloxacin and ofloxacin respectively, but the susceptibility to spectinomycin, cephalosporin and cefoxitin was good . The resistant rates of Mycoplasma to tetracycline, acetylspiramycin, erythromycin, and ofloxacin were 50.0% or more, but the susceptibilities to roxithromycin, doxycyclin, levofloxacin, minocyclin, josamycin, and azithromycin were about 70.0%-80.0% . CONCLUSION: The isolation rate of Mycoplasma is higher than that of Neisseria gonorrhoeae and Chlamydia trachomatis in the chronic prostatitis . It is important to detect the susceptibility of Neisseria gonorrhoeae and Mycoplasma for the use of antibiotics in reason. Infect Immun, 2003 Sep, 71(9), 5427 - 31 Characterization of a ComE3 homologue essential for DNA transformation in Helicobacter pylori; Yeh YC et al.; To find genes involved in natural competence in Helicobacter pylori, we used a bioinformatics database search and found two transformation-related open reading frames (ORFs): a comE3 homologue (HP1361 ORF) of Bacillus subtilis and a comL homologue (HP1378 ORF) of Neisseria gonorrhoeae . We failed to obtain an HP1378 ORF knockout mutant, while an HP1361 ORF knockout mutant was obtained by transposon shuttle mutagenesis . The DNA transformation abilities of both natural transformation and electroporation were severely impaired (frequency, <10(-9)) in the HP1361(-) mutant . Complementation with a pHel2 vector carrying the HP1361 ORF restored the capabilities of natural competence (to a frequency of 4.21 x 10(-7)) and electroporation (to 3.62 x 10(-7)) . The HP1361(-) mutant showed impairment in DNA binding and uptake . The results suggest that HP1361 is a comE3 homologue and is required for DNA binding and uptake during DNA transformation. Biostatistics, 2000 Sep, 1(3), 341 - 54 Product limit estimation for infectious disease data when the diagnostic test for the outcome is measured with uncertainty; Richardson BA et al.; Low sensitivity and/or specificity of a diagnostic test for outcome results in biased estimates of the time to first event using product limit estimation . For example, if a test has low specificity, estimates of the cumulative distribution function (cdf) are biased towards time zero, while estimates of the cdf are biased away from time zero if a test has low sensitivity . In the context of discrete time survival analysis for infectious disease data, we develop self-consistent algorithms to obtain unbiased estimates of the time to first event when the sensitivity and/or specificity of the diagnosti