Typhoid Carriers Research Articles

Antiquorum sensing and antibiofilm potential of biosynthesized silver nanoparticles of Myristica fragrans seed extract against MDR Salmonella enterica serovar Typhi isolates from asymptomatic typhoid carriers and typhoid patients

Globally, Salmonella infection poses a major public health problem. Here, we report antibiofilm activity and quorum sensing inhibition of aqueous seeds extract of Myristica fragrans (nutmeg) and biosynthesized silver nanoparticles (AgNPs) against multidrug resistant (MDR) Salmonella enterica serovar Typhi (S. Typhi) isolated from typhoid patients and asymptomatic carriers. S. Typhi isolates revealed higher percentage (46%) of biofilm production identified by tissue culture plate (TCP) than Congo red agar (CRA) and tube adherence (TA) methods. The inhibition of biofilm-producing MDR S. Typhi isolates and pigment production of Chromobacterium violaceum (indicator bacteria) demonstrated the quorum sensing potential of nutmeg. The aqueous seed extract of nutmeg exhibited 87% of antibiofilm activity, while the biosynthesized AgNPs showed 99.1% of antibiofilm activity. Molecular docking studies of bioactive compounds of nutmeg against transcriptional regulatory protein RcsB and sensor kinase protein RcsC revealed interaction with the target proteins. It is proposed that biosynthesized AgNPs could be used as one of the effective candidates in treating asymptomatic typhoid carriers or typhoid patients and to control the subsistence of biofilm-producing S. Typhi strains or other pathogenic bacteria in the environment or industrial settings.

Establishment of Chronic Typhoid Infection in a Mouse Carriage Model Involves a Type 2 Immune Shift and T and B Cell Recruitment to the Gallbladder.

Typhoid fever, caused primarily by Salmonella enterica serovar Typhi (S Typhi), is a life-threatening systemic disease responsible for significant morbidity and mortality worldwide. Three to 5% of individuals infected with S Typhi become chronic carriers due to bacterial persistence in the gallbladder. We have demonstrated that Salmonella forms biofilms on gallstones to establish gallbladder carriage. However, an in-depth molecular understanding of chronic carriage in the gallbladder, from the perspective of both the pathogen and host, is poorly defined. To examine the dynamics of the gallbladder in response to Salmonella infection, we performed transcriptional profiling in the mouse gallbladder at early (7 days) and chronic (21 days) time points. Transcriptome sequencing (RNA-Seq) revealed a shift from a Th1 proinflammatory response at 7 days postinfection (dpi) toward an anti-inflammatory Th2 response by 21 dpi, characterized by increased levels of immunoglobulins and the Th2 master transcriptional regulator, GATA3. Additionally, bioinformatic analysis predicted the upstream regulation of characteristic Th2 markers, including interleukin-4 (IL-4) and Stat6. Immunohistochemistry and fluorescence-activated cell sorter (FACS) analysis confirmed a significant increase in lymphocytes, including T and B cells, at 21 dpi in mice with gallstones. Interestingly, the levels of Salmonella-specific CD4 T cells were 10-fold higher in the gallbladder of mice with gallstones at 21 dpi. We speculate that the biofilm state allows Salmonella to resist the initial onslaught of the Th1 inflammatory response, while yet undefined events influence a switch in the host immunity toward a more permissive type 2 response, enabling the establishment of chronic infection.IMPORTANCE The existence of chronic typhoid carriers has been in the public eye for over 100 years in part because of the publicity around Typhoid Mary. Additionally, it has been known for decades that the gallbladder is the main site of persistence and recently that gallstones play a key role. Despite this, very little is known about the physiological conditions that allow Salmonella enterica serovar Typhi to persist in the gallbladder. In this study, we analyze the transcriptional profile of the gallbladder in a mouse model of chronic carriage. We found a shift from an early proinflammatory immune response toward a later anti-inflammatory response, which could explain the stalemate that allows Salmonella persistence. Interestingly, we found a 10-fold increase in the number of Salmonella-specific T cells in mice with gallstones. This work moves us closer to understanding the mechanistic basis of chronic carriage, with a goal toward eradication of the disease.

On-treatment improvement of an emerging psychosomatic depressive disorder among salmonella carriers: a multicenter experience from Egypt.

BackgroundAs physicians in a referral hospital, we observed the association between history of enteric fever and somatic disorders associated with low mood. At the Al-Hussein University Hospital, Cairo and the National Liver Institute Hospital, Menoufia, we receive patients from all over Egypt, including rural areas where enteric fever is endemic.AimHere in, 60 Egyptian patients referred to us for evaluation of different somatic disorders are reported.MethodsAfter extensive evaluations, the patients’ symptoms were function-related. Also, their typhoid carrier states were documented, and the severity of depression using Hamilton-D (HAM-D) questionnaire was evaluated and recorded. All patients were treated with ceftriaxone, 2 gm, IV, daily for 15 days. The clinical evaluation and Hamilton score were reassessed at the end of the treatment and 6 weeks thereafter. The patients did not receive any anti-depressant nor anti-anxiety treatment during their course. Typhoid carrier was defined by documenting the history of typhoid fever that was diagnosed by culturing the Salmonella species, and not by serology, isolated from stool culture along with febrile condition, plus the absence of fever in the past 3 weeks. The Widal test was not accepted as a criterion for enrollment.ResultsPatients showed clinically significant improvement in the somatic complaints, and their HAM-D score immediately post-treatment that was consolidated for 6 weeks post-treatment completion.ConclusionIn this study, the typhoid carrier was associated with the psychosomatic depression that improved by antibiotic therapy.

A Case Series for Salmonella Carriers Who Presented with Psychosomatic Depressive Disorder and Showed Improvement after Ceftriaxone Treatment for 15 Days

Background: Based on our observations, as physicians in a Referral Hospital, we have been noticing the association between history of enteric fever and somatic disorders associated with low mood. At our hospital, Al- Hussein University Hospital, Cairo, Egypt, we are receiving patients from all over Egypt, including rural areas where enteric fever is endemic. Here we report this series for 15 patients referred to us for evaluation of different somatic disorders. Clinical presentation: After extensive evaluations, the patients’ symptoms were proved to be functional, their typhoid carrier states were documented, they were evaluated for depression using Hamilton-D questionnaire and the severity of depression was recorded. All patients were treated by ceftriaxone, 2 g, IV, daily for 15 days. Clinical evaluation and Hamilton score were reassessed at the end of treatment and 6 weeks thereafter. The patients did not receive any anti-depressant nor anti-anxiety treatment during their course. Typhoid carrier was defined by documenting the history of typhoid fever that was diagnosed by culturing the Salmonella species not by serology, plus at least one occasion of Salmonella isolates from stool culture while afebrile, plus absence of fever in the past 3 weeks. The Widal test wasn’t accepted as a criterion for enrolment. Results: Patients showed clinically significant improvement in term of the presenting somatic complaints as well as their Hamilton-D score immediately post-treatment and consolidate for 6 weeks post-treatment completion. Conclusion: Typhoid carrier in our series was associated with psychosomatic depression that improved on antibiotic therapy.

Is Salmonella enterica serovar Typhi associated with carcinoma gall bladder?

Introduction: Gallbladder carcinoma is a common hepatobiliary malignancy with poor prognosis. It is 3rd commonest malignancy in north India. Salmonella typhi is one of risk factor for gallbladder cancer. India is high endemic area for typhoid in the world. Various authors reported association between the two but without doing testing for typhoid carrier, association cannot be proven. Aim: The present study was designed to explore the association of the chronic typhoid carrier state and carcinoma gall bladder by detecting Salmonella typhi in specimens of gallbladder from patients with malignant and benign gallbladder diseases using a Nested PCR. Methods and material: In this prospective case control study, we have got 39 samples from Carcinoma Gall Bladder (GBC) patients as cases and 75 samples from benign Gall Bladder Diseases (GBD) patients as controls in two years duration. We have done Indirect haemagglutination test for typhoid carrier from five milliliters of blood which was collected from each patient before surgery. Nested PCR was done from gall bladder tissue, which was taken at operation, from both GBC and GBD patients. Result: Nested PCR showed 59% positivity for Salmonella typhi in the GBC and 56% in GBD, so association of Salmonella typhi with GBC was not statistically significant. Vi antibody was present 33% in GBC and 37% in GBD by IHA. It is also not statistically significant. Conclusion: A large number of sample size is require for proving association between carcinoma gall bladder and Salmonella typhi by using definite marker for Vi antibodies.

Transcriptomic study of Salmonella enterica subspecies enterica serovar Typhi biofilm

BackgroundTyphoid fever is an acute systemic infection of humans caused by Salmonella enterica subspecies enterica serovar Typhi (S. Typhi). In chronic carriers, the bacteria survive the harsh environment of the gallbladder by producing biofilm. The phenotype of S. Typhi biofilm cells is significantly different from the free-swimming planktonic cells, and studies have shown that they are associated with antibiotic resistance, immune system evasion, and bacterial persistence. However, the mechanism of this transition and the events leading to biofilm formation are unknown. High throughput sequencing was performed to identify the genes involved in biofilm formation and to postulate the mechanism of action.ResultsPlanktonic S. Typhi cells were cultured using standard nutrient broth whereas biofilm cells were cultured in a stressful environment using high shearing-force and bile to mimic the gallbladder. Sequencing libraries were prepared from S. Typhi planktonic cells and mature biofilm cells using the Illumina HiSeq 2500 platform, and the transcriptome data obtained were processed using Cufflinks bioinformatics suite of programs to investigate differential gene expression between the two phenotypes. A total of 35 up-regulated and 29 down-regulated genes were identified. The identities of the differentially expressed genes were confirmed using NCBI BLAST and their functions were analyzed. The results showed that the genes associated with metabolic processes and biofilm regulations were down-regulated while those associated with the membrane matrix and antibiotic resistance were highly up-regulated.ConclusionsIt is proposed that the biofilm phenotype of S. Typhi allows the bacteria to increase production of the membrane matrix in order to serve as a physical shield and to adhere to surfaces, and enter an energy conservation state in response to the stressful environment. Conversely, the planktonic phenotype allows the bacteria to produce flagella and increase metabolic activity to enable the bacteria to migrate and form new colonies of infection. This data provide a basis for further studies to uncover the mechanism of biofilm formation in S. Typhi and to discover novel genes or pathways associated with the development of the typhoid carrier state.

Molecular and Phenotypic Characteristics of Salmonella enterica Serovar Typhi Isolated from Asymptomatic Carrier

Background: Salmonella enterica serovar typhi (S. typhi ) the cause of the acute febrile disease typhoid fever is the major public health problem in developing countries. Asymptomatic carriers are the main sources of typhoid. The aim of this study was to investigate methods for isolation and identification of S. typhi in asymptomatic carriers. Materials and Methods: Two hundred stool samples were collected from foodstuff workers and distributors. Then culture characterization, biochemical tests, and nested-PCR were done. Results: One hundred and seventy-one (85%) of the total cases were male and the mean age of cases was 35 years. Stool culture yielded bacterial colonies consistent with fecal flora but did not yield S. typhi . In nested PCR technique just one of the 200 samples (0.5%) was positive for the S. typhi capsular gene (vi gene). Conclusion: Due to the improvement in the health status of the country and the low typhoid carriers, it is recommended that efforts be focused on other hygienic issues.

Analysis of TLR polymorphisms in typhoid patients and asymptomatic typhoid carriers among the schoolchildren

BackgroundToll like receptor (TLR) plays a critical role in recognition and activation of both innate and adaptive immune responses against microbial pathogens. Several studies have implicated the genetic variations (polymorphisms) in TLR genes to influence the host susceptibility to infectious diseases. However, the available literature on TLR polymorphism and susceptibility to typhoid fever is unclear. AimThis study aimed to investigate the polymorphism of TLRs 1, 2, 4 and 5 in typhoid patients and convalescent phase asymptomatic typhoid carriers among the schoolchildren. Subjects and methodsTLR genes were amplified by PCR from peripheral blood leukocytes of schoolchildren with typhoid (n=20) or asymptomatic typhoid carrier (n=30) state, and normal healthy individuals (n=50). The RFLP analyses for TLR1, 2, 4 and 5 genes using restriction enzymes such as AluI, AciI, NcoI and DdeI, respectively, were performed to determine the single nucleotide polymorphism. ResultsTLR1 polymorphism was observed in 5% (1/20) of typhoid patients and 6.6% (2/30) of typhoid carriers. TLR2 polymorphism was observed in 10% (2/20) of typhoid patients and 6.6% (2/30) of carriers. TLR4 polymorphism was not observed in typhoid patients, but 6.6% (2/30) of typhoid carriers exhibited a polymorphism. As well, TLR5 polymorphism was not observed in typhoid patients, while 13.3% (4/30) of typhoid carriers had polymorphism. None of the control healthy individuals had evidence for TLR polymorphisms. ConclusionThe study reports polymorphisms of TLR genes in a lower proportion among the schoolchildren with typhoid or convalescent typhoid carrier state.

Complete Genome Sequence of Salmonella enterica subsp. enterica Serovar Typhi Isolate B/SF/13/03/195 Associated with a Typhoid Carrier in Pasir Mas, Kelantan, Malaysia.

We report here the complete genome sequence of Salmonella enterica subsp. enterica serovar Typhi B/SF/13/03/195 obtained from a typhoid carrier, who is a food handler in Pasir Mas, Kelantan.

Role of Gallstones in Typhoid Carriage in Egyptian Patients

Objectives: Salmonella typhi forms biofilm on the surface of gallstones promoting colonization and carrier state. The aims are to detect its frequency in chronic calcular cholecystitis patients, to find out their antibiotic resistance pattern, and also to examine biofilm on the surface of gallstones and detect its correlation to antibiotic susceptibility pattern. Materials and methods: The study group included 257 patients with chronic calcular cholecystitis. S. typhi was isolated from gall bladder specimens. Antibiotics susceptibility tests of the isolates were done. Biofilm on surface of gallstones were visualized using scanning electron microscopy. Virulence (Vi) antibodies against S. typhi were studied in sera of 257 healthy controls. Results: 10.9% of patients were chronic typhoid carriers compared to only 3.5% of the controls (OR= 3.37, p=0.002). Multidrug resistance was detected in 35.7% of isolates. S. typhi biofilms on the surface of the 21/28 (75%) gallstones were detected. Ninety percent of the strains that produced maximum amount of biofilm were multidrug-resistant. Conclusion: Chronic calcular cholecystitis patients are more prone to typhoid carriage due to biofilm formation of S. typhi on the surface of gallstones. J Microbiol Infect Dis 2012; 2(4): 142-149

A prevalence study of typhoid fever and convalescent phase asymptomatic typhoid carriers among the schoolchildren in the northern part of Tamil Nadu

This study reports, for the first time, the prevalence of typhoid fever and convalescent phase asymptomatic typhoid carriers among the schoolchildren in Vellore district of Tamil Nadu state in India. Blood and stool samples (n = 500) were collected from the schoolchildren, who were admitted to District Government hospitals for treatment of typhoid fever or other enteric disorders. Early morning stool and blood samples (n = 700) were collected from the schoolchildren, who had the previous history of typhoid fever. The blood and stool samples were subjected to immunological and bacteriological examination to confirm the cases of typhoid fever and typhoid carriers. Further, S. Typhi isolates from the typhoid patients and asymptomatic carriers were serogrouped by standard protocols at WHO Reference laboratory for Salmonella typing in India. A total of 360/500 (72%) children were positive for typhoid fever; while a total of 147/700 (21%) children were confirmed as convalescent phase asymptomatic typhoid carriers. All the S. Typhi isolates obtained from children positive from typhoid fever or typhoid carriers in this region were found to be serovars 9, 12, Vi: d and 4, 12: i: 1, 2. This study highlights the prevalence of typhoid fever among the schoolchildren and a possible role of convalescent phase asymptomatic typhoid carriers as a risk factor for the spread of infection in this locality.

Titer IgG anti-flagellum Antibody and Flagellin Gene Variants of Salmonella enterica Serovar Typhi as Risk Factor for Typhoid Fever Carriers

Background: Salmonella enterica serovar Typhi (S. Typhi) is a human-specific pathogen that causes typhoid fever. Typhoid fever remains a global health problem especially in developing countries. Pathogenesis of typhoid fever is complex and host response is poorly understood.There is an urgent need for adequate and efficient detection methods for the establishment of carrierstate of typhoid fever as a source of transmission. We compared IgG anti-flagellar antibody and fagellin gene variants of S. Typhi to explore risks factor of typhoid fever carriers. Method: Serum and fecal swab samples obtained from 379 suspected for typhoid carrier. Typhoid carriers were identified when home visits of patients who have recovered from typhoid fever at least 1 year.In-house indirect sandwich ELISA were established to detect anti-flagellum IgG.DNA Samples obtained directly from fecal swab were confirmed to be serovar Typhi by nested PCR. All specimens were examined for their Hd, Hj, z66 and z66 Ind flagellin genes by Polymerase Chain Reaction (PCR). Results: A total of 379 suspected patients, where examined by nested PCR to detect specific flagellin gene for S. typhi, and found 21 (5.28%) samples were positive. Serum samples from all suspected typhoid carrier were examined by ELISA to detect titer of anti-flagellum IgG. Of 21 typhoid carrier patients, there were 2 (9.5%) patients had Hd+ variant; one (4.8%) patient had Hj+ variant; 6 (28.6%) patients had Hd+Z66+ variant; one (4.8%) patient had Hj+ Z66+ variant and 11 (52.3%) patients had Hd+Z66IND+ variant. There were 34 patients positive for anti-flagellum IgG antibody after examine by ELISA. Among PCR positive patients there were 14 patients had high titer and 7 patients had low titer of anti-flagellum IgG antibody. Within PCR negative we found 13 patients with low titer of anti-flagellum IgG. Conclusions: We conclude that patient harboring Hd+Z66IND+ gene of S. Typhi and High titer of IgG antibody anti-flagellum S. Typhi considered to be risk factor for typhoid carriers development.

Induction of deletion mutation on ompR gene of Salmonella enterica serovar Typhi isolates from asymptomatic typhoid carriers to evolve attenuated strains for vaccine development.

To develop attenuated strains of Salmonella enterica serovar Typhi (S. typhi) for the candidate vaccine by osmolar stress. S. typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in Namakkal, Tamil Nadu, India. Both strains were grown in LB (Luria Bertani) medium supplemented with various concentration of NaCl (0.1-0.7M) respectively. The effect of osmolar stress was determined at molecular level by PCR using MGR 06 and MGR 07 primers corresponding to ompR with chromosomal DNA of S. typhi SS3 and SS5 strains. Attenuation by osmolar stress results in deletion mutation of the S. typhi strains was determined by agglutination assays, precipitation method, SDS PAGE analysis and by animal models. The 799 bp amplified ompR gene product from wild type S. typhi SS3 and SS5 illustrate the presence of virulent gene. Interestingly, there was only a 282 bp amplified product from S. typhi SS3 and SS5 grown in the presence of 0.5, 0.6 and 0.7 M NaCl. This illustrates the occurrence of deletion mutation in ompR gene at high concentration of NaCl. Furthermore, both the wild-type and mutant S. typhi outer membrane SDS-PAGE profile reveals the differences in the expression of ompF, ompC and ompA proteins. In mice, wild type and mutant strains lethal dose (LD50) were determined. The mice died within 72 h when both the wild type strains were injected intraperitoneally with 3 log CFU.mL(-1). When the mice were injected with the mutants in same dosage, no clinical symptoms were observed; whereas the serum antibody titre was elicited within two weeks indicated that the mutants have the ability to induce protective humoral immune response. These results suggest that S. typhi SS3 and SS5 may be used as good candidate strains for the development of live attenuated vaccine against salmonellosis. This study demonstrates that the S. typhi strains were attenuated and could be good vaccine candidates in future.

Acid exposure induces multiplication of Salmonella enterica serovar Typhi.

Salmonella enterica serovar Typhi faces several environmental stresses while going through the stomach (acidic pH) to the small intestine (basic pH) and intracellularly in macrophages (acidic pH) in humans. The acidic pH followed by alkaline pH in the small intestine might be responsible for expression of certain stress-induced genes, resulting in not only better survival but also induction of multiplication and invasion of the bacterium in the small intestine. Based on this hypothesis, we developed a process wherein we exposed the blood, urine, and stool specimens from 90 acute typhoid fever patients and 36 chronic typhoid carriers to acidic pH to see the effect on isolation rate of S. Typhi. About 5 g of freshly passed unpreserved stool, a centrifuged deposit of 15 ml of urine, and 5 ml of blood clot were subjected to 5 ml of Luria-Bertani (LB) broth (pH 3.5) for 20 min, followed by enrichment in bile broth-selenite F broth. When the combined isolation from all 3 specimens, i.e., blood, urine, and stool, after acid exposure was considered, a total of 77.7% of the acute typhoid patients were observed to be positive for the isolation of the S. Typhi serotype, compared to 8.8% by the conventional method. Similarly, 42% (15/36) of chronic carriers yielded positive for S. Typhi growth after acid exposure, compared to 5.5% (2/36) by the conventional method. It therefore can be concluded that acid shock triggers the multiplication of the bacteria, resulting in better isolation rates from blood clot, stool, and urine specimens.

Typhoid fever in Fiji: a reversible plague?

The country of Fiji, with a population of approximately 870 000 people, faces a growing burden of several communicable diseases including the bacterial infection typhoid fever. Surveillance data suggest that typhoid has become increasingly common in rural areas of Fiji and is more frequent amongst young adults. Transmission of the organisms that cause typhoid is facilitated by faecal contamination of food or water and may be influenced by local behavioural practices in Fiji. The Fijian Ministry of Health, with support from Australian Aid, hosted a meeting in August 2012 to develop comprehensive control and prevention strategies for typhoid fever in Fiji. International and local specialists were invited to share relevant data and discuss typhoid control options. The resultant recommendations focused on generating a clearer sense of the epidemiology of typhoid in Fiji and exploring the contribution of potential transmission pathways. Additionally, the panel suggested steps such as ensuring that recommended ciprofloxacin doses are appropriate to reduce the potential for relapse and reinfection in clinical cases, encouraging proper hand hygiene of food and drink handlers, working with water and sanitation agencies to review current sanitation practices and considering a vaccination policy targeting epidemiologically relevant populations.

A comparative analysis of TLR5 polymorphism and clinical parameters in typhoid patients and asymptomatic typhoid carriers

Aim Typhoid fever is a serious health problem in tropical and developing countries. Although asymptomatic typhoid carriers show no clinical signs, they can spread infection to others. This study investigated the Toll like receptor 5 (TLR5) polymorphism and various clinical parameters in typhoid patients and asymptomatic typhoid carriers.

Proteomics-based identification of plasma proteins and their association with the host–pathogen interaction in chronic typhoid carriers

SummaryBackgroundCurrent diagnostic tests are inadequate to detect typhoid cases, as well as the chronic carrier state, the sole reservoir of Salmonella enterica serovar Typhi. The current study was conducted to find new molecular signatures of pathogen/disease to understand the mechanism behind the host–pathogen interaction in enteric fever.MethodsProteomics-based studies were done to determine the expression of differentially expressed proteins in the plasma of controls, acute typhoid cases, and chronic typhoid carriers. Further, transcriptome-based analysis using reverse-transcriptase PCR (RT-PCR) was done in controls, acute typhoid cases, and chronic typhoid carriers.ResultsResults showed the upregulation of proprotein convertase subtilisin, furin, haptoglobin, and albumin in the plasma of chronic typhoid carriers. The elevation in mRNA expression of four differentially expressed proteins confirms the changes at the transcriptional level. Further, the increase in albumin and haptoglobin in chronic typhoid carriers shows their role in free radical generation, inflammation, and monocyte cell signaling.ConclusionThrough proteomics techniques, this study identified four proteins in the chronic typhoid carrier host that may have a role in the disease pathogenesis of enteric fever.

Targeting of putative fimbrial gene for detection of S. Typhi in typhoid fever and chronic typhoid carriers by nested PCR

It is important to identify Salmonella Typhi infection quickly to treat acute fever patients and to prevent transmission by chronic typhoid carriers; therefore, a very specific and sensitive diagnostic technique is highly desirable, especially in endemic areas. The objective of this study was to develop a PCR protocol targeting the putative fimbrial staA gene of S. Typhi. This is a preferred target gene that is specifically amplified in the S. Typhi serotype compared to the commonly targeted fliC gene which may also be amplified from the non-typhoidal Salmonella Munchen serotype. A new nested PCR primer methodology was designed to target the staA gene, which is a member of the fimbrial gene family specific to Salmonella Typhi only. The primers were found to be very specific as the desired amplicon (377 bp) could be generated exclusively from S. Typhi strains including the reference strain (MTCC 3216) and 78 clinical isolates . Restriction digestion with HinfI confirmed the identity of the amplified DNA fragment in clinical specimens of S. Typhi origin. Furthermore, these primers were able to detect a minimum of three colony forming units per ml (1fg) in spiked blood samples. The detection sensitivity of the described primers is comparable to that of previously published primers targeting fliC gene sequences. This study indicates that the primers targeting the putative fimbrial staA gene are very specific to the Typhi serotype and may be a better alternative to fliC targeted amplification based diagnosis.

The Genomic Blueprint of Salmonella enterica subspecies enterica serovar Typhi P-stx-12

Salmonella enterica subspecies enterica serovar Typhi is a rod-shaped, Gram-negative, facultatively anaerobic bacterium. It belongs to the family Enterobacteriaceae in the class Gammaproteobacteria, and has the capability of residing in the human gallbladder by forming a biofilm and hence causing the person to become a typhoid carrier. Here we present the complete genome of Salmonella enterica subspecies enterica serotype Typhi strain P-stx-12, which was isolated from a chronic carrier in Varanasi, India. The complete genome comprises a 4,768,352 bp chromosome with a total of 98 RNA genes, 4,691 protein-coding genes and a 181,431 bp plasmid. Genome analysis revealed that the organism is closely related to Salmonella enterica serovar Typhi strain Ty2 and Salmonella enterica serovar Typhi strain CT18, although their genome structure is slightly different.

Epidemiological factors in gall bladder cancer in eastern India-a single centre study.

India has high incidence of Gallbladder carcinoma with regional variation in incidence possibly due to environmental factors. Prospective study of all the gall bladder cancer in our hospital over 18months analysing how the epidemiological factors are influencing the disease. Incidence-Four cases per 100,000 populations per year. The peak incidence was in 41 to 50years group (49.20%). Male to female ratio was 1:3.8. Majority (69.84%) were in lower socio-economic group. 61 out of 63 patients (96.62%) were non-vegetarians. 60.34% and 19.04% patients weighed between 50 and 55kg and 55and 60kg respectively (p = 0.003). Male smokers had significantly higher risk (p = 0.000 1). Gall stones were present in 45 out of 63 cases(71.42%).45 out of 63 patients were typhoid carriers (p < 0.05). Pain abdomen was the commonest complaint (87.30%), followed by pallor, lump in right upper quadrant, nausea & vomiting and jaundice in 71.42%, 69.84%, 66.66%, 31.74% patients respectively. This data highlights high prevalence of gall bladder carcinoma in Eastern India. Better hygiene and water supply to prevent typhoid carriers, prevention of malnutrition, early intervention for cholelithiasis, importance of balanced diet, increase in awareness about risk of tobacco and alcohol consumption-all are highlighted as significant modifiable factors.