Reactividad de sueros de ratones inmunizados con vesículas de membrana externa derivadas de Salmonella entérica / Reactivity of sera from mice immunized with outer membrane vesicles derived from Salmonella enterica

La fiebre tifoidea causada por Salmonella Paratyphi A (fiebre paratifoidea) es indistinguible de la producida por Salmonella Typhi y el grado de incidencia ha aumentado en los últimos años, especialmente en el sudeste asiático. Por otro lado, la diarrea y otras complicaciones entéricas causadas por Salmonella Enteritidis y Salmonella Typhimurium continúan siendo un problema de salud grave, especialmente en países subdesarrollados. Las vacunas continúan siendo la forma más efectiva de prevenir estas enfermedades. Existen vacunas basadas en el polisacárido capsular de Salmonella Typhi que protegen contra la fiebre tifoidea; sin embargo, no hay vacunas efectivas licenciadas para uso en humanos que prevengan las enfermedades producidas por los serotipos de Salmonella no tifoideas. El desarrollo de una formulación con capacidad para proteger contra estas enfermedades sigue siendo un desafío para la comunidad científica. En este trabajo se evaluó, mediante Western blot, la reactividad de los sueros de ratones inmunizados por vía subcutánea con formulaciones basadas en vesículas de membrana externa derivadas de Salmonella Paratyphi A, Salmonella Enteritidis y Salmonella Typhimurium, contra los respectivos lisados celulares, para identificar la formulación que induce la mejor respuesta inmunológica cruzada. Los resultados obtenidos indicaron una alta reactividad de todos los sueros a los lisados, sin una diferencia aparente entre ellos. Sin lugar a dudas, se deberán realizar pruebas de inmunogenicidad seguidas de pruebas de retos cruzados para identificar un candidato vacunal. Estos resultados sugieren que las vesículas de membrana externa empleadas en este estudio están compuestas por antígenos posiblemente conservados en los tres serotipos de Salmonella y que pueden inducir una respuesta inmune de amplio espectro y protección cruzada(AU)

Typhoid fever caused by Salmonella Paratyphi A (paratyphoid fever) is indistinguishable from that caused by Salmonella Typhi and the degree of incidence has increased in recent years, especially in Southeast Asia. On the other hand, diarrhea and other enteric complications caused by Salmonella Enteritidis and Salmonella Typhimurium continue to be a serious health problem, especially in underdeveloped countries. Vaccines continue to be the most effective way to prevent these diseases. There are vaccines based on Salmonella Typhi capsular polysaccharide, which protects against typhoid fever; however, there are no effective vaccines licensed for use in humans to prevent disease caused by nontyphoidal Salmonella serotypes. Developing a formulation capable of protecting against these diseases remains a challenge for the scientific community. In this work, the reactivity of the sera of mice immunized subcutaneously with formulations based on Outer Membrane Vesicles (OMV) derived from Salmonella Paratyphi A, Salmonella Enteritidis and Salmonella Typhimurium, was evaluated by Western blot, against the respective cell lysates to identify the formulation that induces the best cross immune response. The results obtained indicated a high reactivity of all the sera to the lysates; without an apparent difference between them. Undoubtedly, immunogenicity tests followed by cross-challenge tests should be performed to identify a vaccine candidate. These results suggest that the OMV used in this study are composed of possibly conserved antigens in the three Salmonella serotypes and that they can induce a broad-spectrum immune response and cross protection(AU)

Estandarización de un ELISA para la cuantificación de anticuerpos IgG contra vesículas de membrana externa de Salmonella Paratyphi A / Standardization of an ELISA for the quantification of IgG antibodies against outer membrane vesicle of Salmonella Paratyphi A

Salmonella Paratyphi A es un patógeno exclusivo de humanos, siendo la segunda causa más común de fiebre entérica en el sudeste asiático. Recientemente la incidencia en este continente ha aumentado, desplazando a Salmonella entérica serotipo Typhi como la primera causa de fiebre entérica. En la actualidad no existen vacunas licenciadas contra S. Paratyphi A. El Instituto Finlay de Vacunas se encuentra trabajando en la obtención de un candidato vacunal basado en vesículas de membrana externa (VME) contra S. Paratyphi A, por lo que se hizo necesario contar con una técnica para la evaluación de su inmunogenicidad. El objetivo de este trabajo fue la estandarización de un ELISA para la cuantificación de anticuerpos IgG contra VME de S. Paratyphi A. Para ello, se determinaron las mejores condiciones de este ensayo en cuanto a concentración óptima de recubrimiento y dilución de trabajo del conjugado. Además, se definió el intervalo y linealidad de la curva, la precisión intra e interensayo, la especificidad y el límite de detección. La curva de calibración se generó con un suero estándar interno y presentó un buen ajuste lineal con un R² =0.98. Los coeficientes de variación en los ensayos de precisión intra e interensayo estuvieron en los intervalos establecidos para cada uno (=10 por ciento, =20 por ciento respectivamente). Los resultados obtenidos avalan el empleo de este ELISA cuantitativo para la evaluación de la inmunogenicidad de formulaciones de VME de S. Paratyphi A en fases de investigación y desarrollo(AU)

Salmonella Paratyphi A, is an exclusive pathogen of humans, being the second most common cause of enteric fever in Southeast Asia. Recently the incidence of this disease in this continent has increased, displacing Salmonella enterica serotype Typhi as the first cause of enteric fever. Currently there are no vaccines licensed against S. Paratyphi A. The Finlay Institute of Vaccines is working on obtaining a vaccine candidate based on outer membrane vesicles (VME) against S. Paratyphi A, so it became necessary to develop a technique for the evaluation of its immunogenicity. The objective of this work was the standardization of an ELISA for the quantification of IgG antibodies against VME of S. Paratyphi A. The best conditions of this assay were determined in terms of optimum concentration of coating and working dilution of the conjugate. In addition, the interval and linearity of the curve, the intra- and inter-assay precision, the specificity and the limit of detection were defined. The calibration curve was generated with an internal standard serum and presented a good linear fit with an R² =0.98. The coefficients of variation in the intra- and interassay precision tests were in the intervals established for each one (=10 percent, =20 percent respectively). The results obtained support the use of this quantitative ELISA for the evaluation of the immunogenicity of VME formulations of S. Paratyphi A in research and development phases(AU)

Enteric Fever in a Tertiary Paediatric Hospital: A Retrospective Six-Year Review

<p><b>INTRODUCTION</b>Enteric fever is a multisystemic infection which largely affects children. This study aimed to analyse the epidemiology, clinical presentation, treatment and outcome of paediatric enteric fever in Singapore.</p><p><b>MATERIALS AND METHODS</b>A retrospective review of children diagnosed with enteric fever in a tertiary paediatric hospital in Singapore was conducted from January 2006 to January 2012. Patients with positive blood cultures for Salmonella typhi or paratyphi were identified from the microbiology laboratory information system. Data was extracted from their case records.</p><p><b>RESULTS</b>Of 50 enteric fever cases, 86% were due to Salmonella typhi, with 16.3% being multidrug resistant (MDR) strains. Sixty-two percent of S. typhi isolates were of decreased ciprofloxacin susceptibility (DCS). Five cases were both MDR and DCS. The remaining 14% were Salmonella paratyphi A. There were only 3 indigenous cases. Ninety-four percent had travelled to typhoid-endemic countries, 70.2% to the Indian subcontinent and the rest to Indonesia and Malaysia. All patients infected with MDR strains had travelled to the Indian subcontinent. Anaemia was a significant finding in children with typhoid, as compared to paratyphoid fever (P = 0.04). Although all children were previously well, 14% suffered severe complications including shock, pericardial effusion and enterocolitis. None had typhoid vaccination prior to their travel to developing countries.</p><p><b>CONCLUSION</b>Enteric fever is largely an imported disease in Singapore and has contributed to significant morbidity in children. The use of typhoid vaccine, as well as education on food and water hygiene to children travelling to developing countries, needs to be emphasised.</p>

Determination of baseline Widal titre in healthy individuals in Karbala city, South of Iraq

Objective: To determine the cutoff of antibodies directed against Salmonella enterica subspecies enterica serotype typhi, paratyphi A, and paratyphi B in normal population in Karbala city, south Iraq

Methods: Widal test was performed for 90 serially diluted serum samples collected from apparently healthy volunteers. A commercial Widal test kit was used. Agglutination results were observed within 1 minute

Results: In the current study, 23.33%, 22.22%, 6.6%, 4.4%, 38.88% and 5.55% of individuals had antibody titre >/=1:20 for S. enterica subspecies enterica serotype typhi O, H, S. enterica serotype paratyphi AO, AH, S. enterica serotype paratyphi BO and BH, respectively

Conclusion: Based on these results, antibody titres of 1:160 for O and H, 1:40 for AO, 1:80 for AH and BH and 1:320 for BO antigens were considered as baseline titre in Karbala

Inhibitory effects of several essential oils towards salmonella typhimurium, salmonella paratyphi A and salmonella paratyphi B

Plant essential oils are natural products extracted from plants and because of their antimicrobial properties can be used as natural additives in foods. They are also useful for decontamination of food-borne pathogens and can be a safe additive in foods. The antimicrobial activities of essential oils belonging to Saturiea hortensis, Thymus vulgaris, Mentha polegium, Cuminum cyminum, Lavandula officinalis and Mentha viridis L. [spearmint] were investigated at different concentrations [0.1, 0.3, 0.5, 1, 2, 5 and 10%v/v] against Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B by using the agar well diffusion method. Essential oils showed inhibitory effect on Salmonella spp. in the agar well diffusion assay. In addition, the capability of essential oils for decontamination of minced row beef, ground beef, minced raw chicken and minced raw fish inoculated with Salmonella spp. at 0.1 and 0.5%v/v were assessed. Reduction of the Salmonella spp. population was observed following the inoculation of the cultures with 0.1 and 0.5%v/v essential oils

Literature Review and Clinical Presentation of Cervical Spondylitis Due to Salmonella Enteritidis in Immunocompetent

A 48-year-old woman was presented to our clinic with some fever and neck pains for about one month. Based on the symptoms and results of image, an empirical diagnosis of tuberculous cervical spondylitis was made. The pain was not significantly decreased after anti-tuberculosis therapy. And, 3 weeks later, she was re-admitted to our hospital for the unbearable pain. An exploration of the C4/5 by the anterior medial approach was recommended to evaluate the germ and debridement. Bacteriological tests showed that the pathogen was Salmonella Enteritidis. The pain was relieved significantly after operation and sensitive antibiotic treatments. Infections with Salmonella Typhi or Salmonella Paratyphi have been well-documented, while there are few reports of cervical spondylitis caused by Salmonella Enteritidis. We reported a case of a healthy woman with whom pyogenic cervical spondylitis of Salmonella Enteritidis was corroborated and treated and reviewed according to previous reports about spondylitis caused by Salmonella Enteritidis in the literature.

Salmonella spp. in patients suffering from enteric fever and food poisoning in Thamar city, Yemen

Salmonella remains a public health concern around the world, including Yemen although data on its incidence are few. This study determined the incidence of Salmonella infection in 250 enteric fever and 210 food poisoning cases attending Thamar general hospital and Dar Alshafaa medical clinic in 2008. In total, 773 clinical specimens were taken: 250 blood, 187 urine and 336 stool samples. Of the patients with enteric fever and food poisoning, 16.4% and 15.2% respectively were infected with Salmonella. The serovars isolated were: Salmonella Typhi [45.6%], Salmonella Enteritidis [24.4%], Salmonella Paratyphi B [14.4%], Salmonella Typhimurium [13.3%] and Salmonella Paratyphi A [2.2%]. The distribution of somatic groups was: D [70%], B [27.7%] and A [2.2%]. None of the isolates was resistant to ciprofloxacin, sparfloxacin, ceftriaxone or moxifloxacin, while 71.1% were resistant to cotrimoxazole, 62.2% to gentamicin, 56.6% to ampicillin and 35.5% to nalidixic acid

Distribution of Salmonella paratyphi A pagC gene and immunoprotective effect of its recombinant expressed products / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To determine the distribution and sequence conservation of pagC gene in Salmonella paratyphi A isolates, and the immunogenicity and immunoprotection of its recombinant expression products (rPagC).</p><p><b>METHODS</b>The distribution of pagC gene in Salmonella paratyphi A isolates and its sequence conservation were examined by PCR and sequencing. A prokaryotic expression system of pagC gene was constructed and the expressed rPagC was extracted by Ni-NTA affinity chromatography. SDS-PAGE and Bio-Rad Gel Image Analyzer were applied to examine the expression and yield of rPagC. The antigenicity and immunoreactivity of rPagC were detected by immunodiffusion test, ELISA and Western Blot assay. The immunoprotective effect of rPagC against infection of Salmonella paratyphi A in mice was determined, while the agglutinative effect of sera from rPagC-immunized mice was measured by micro-Widal's test.</p><p><b>RESULTS</b>All the Salmonella paratyphi A isolates tested had the pagC gene, the similarity of nucleotide and amino acid sequences was 99.1 %-100 % and 98.4 %-100 %, respectively. The constructed prokaryotic expression system expressed rPagC with high efficiency. The rPagC immunized rabbit produced a high level antibody and it also combined with antiserum against whole cell of S. paratyphi A to generate a positive Western hybridization signal. ELISA results indicated that 97.1 % (66/68) paratyphoid patients infected with Salmonella paratyphi A were positive for rPagC antibody in their serum specimens. When mice were immunized with 100 μg or 200 μg rPagC, the immunoprotective rates were 73.3 % (11/15) or 86.7 % (13/15), respectively. The sera from rPagC-immunized mice offered 1:10-1:40 agglutination titers with the H antigens of Salmonella paratyphi A and Salmonella typhi.</p><p><b>CONCLUSION</b>PagC gene has an extensive distribution in Salmonella paratyphi A isolates. rPagC can be used as the candidate antigen in genetic engineering vaccine due to its fine immunogenicity and powerful immunoprotective effect.</p>

Fever monitoring program in areas with high incidence of typhoid and paratyphoid fever in Guizhou province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the incidence rates of both typhoid fever and paratyphoid fever in the high prevalent areas of Guizhou province so as to provide evidence for the development of programs on comprehensive intervention and effectiveness evaluation.</p><p><b>METHODS</b>Six townships in Pingba county were selected as intervention areas while six townships in Kaiyang county were taken as control. All hospitals and clinics were classified into A, B and C types according to its level and the capacity of the blood culture. Surveillance on typhoid and paratyphoid fever was conducted based on all population and all hospitals, clinics and county CDCs among the patients with unknown fever.</p><p><b>RESULTS</b>In the surveillance area in those two counties, there were 12 944 blood samples from patients with unknown fever which have been tested and cultured. Among them, 200 strains of Salmonella including 16 typhoid strains, 184 paratyphoid A strains were identified, with the total positive rate as 1.55%. The positive rate before the intervention program was higher than the after. The detection rate was 1.91% in the type A hospitals. 39 strains of Salmonella have been cultured from 2039 samples which accounting for 19.50% (39/200) of the total strains. 4315 blood samples were cultured at the 'Class B' sites which isolated 82 strains of Salmonella, accounting for 41.00% (82/200), with a detection rate as 1.90%. 6590 samples were cultured at the 'Class C' sites, which identified 79 strains of Salmonella, accounting for 39.50% (79/200), with a detection rate as 1.20%. The detection rate was much higher before the use of antibiotics than after using them (P < 0.05). The annual peak time of positive detection was in spring and fall. The outbreaks or epidemics often appeared in the same places, with farmers, students as the high-risk populations. Symptoms of both typhoid and paratyphoid fever were not typical.</p><p><b>CONCLUSION</b>Typhoid and paratyphoid monitoring programs which covered primary health care institutions in the high incidence area seemed to be effective in reflecting the pictures as well as the burden of both typhoid and paratyphoid.</p>

Clinical presentation and drug resistance patterns of Salmonellae typhi and paratyphi at a tertiary care hospital of Sindh

The aim of this study is to evaluate the clinical presentation and drug resistance patterns of Salmonellae typhi and paratyphi. Observational Descriptive Study. This study was conducted at the Muhammad Medical Hospital Mirpurkhas, from Jan 2010 to April 2011. One hundred twenty six patients were studied, who satisfied the clinical and laboratory criteria of typhoid/ paratyphoid fever. The blood samples, 5-10 ml from adults were inoculated directly into blood culture bottles. Subcultures were also performed. Antibiotic sensitivity was tested by the Kirby-Bauer technique according to Clinical and Laboratory Standards Institute guidelines. Statistical analysis was performed on SPSS version 10.9 [Chicago, Illinosis, USA], using the chi-square test and student's t-test for the qualitative and quantitative variables respectively. The identified organisms were S.typhi observed in 91 [72.22%], both S typhi/paratyphi in 18 [14.28%] and S.paratyphi A and B in the rest 17 [13.49%]. In 97 [76.98%] of patients, antibody O titers were >/= 1:160 and in 39 [30.95%] titers were <1:160. The overall multi-drug resistant isolates were found in >80% for the first line agent's i.e.; ampicillin, amoxicillin, cotrimoxazole and chloramphenicol. The highest sensitivity rate was found for the cefixime [98.41%] and the lowest one for the ampicillin [22.2%]. We found drug resistant and multi-drug resistant salmonellae in our study; this may be because of antibiotic use as self medication, medication by pharmacist and quacks

Computed tomography features in enteric fever

<p><b>INTRODUCTION</b>Enteric fever is a common infection in endemic areas; however, there are few reports describing the computed tomography (CT) manifestations of enteric fever. We aim to describe and illustrate CT findings in enteric fever in this study.</p><p><b>MATERIALS AND METHODS</b>A retrospective search of medical records in our institute for patients with positive blood cultures for Salmonella typhi, and Salmonella paratyphi organisms yielded 39 cases. Among these patients, 12 had undergone a CT study of the abdomen. The CT images, laboratory and clinical findings of these 12 patients were reviewed.</p><p><b>RESULTS</b>The most common clinical presentation was fever (100%). Typical features of gastroenteritis were present in only over half of the patients. Liver function tests were abnormal in all patients. The most common abdominal manifestations on CT were the presence of mesenteric lymphadenopathy and splenomegaly (75%). Other features were circumferential small bowel wall thickening (58.3%) and free intraperitoneal fluid (50%). Three patients were found to have complications; one with bleeding from terminal ileal ulceration, another with an ileal perforation and the third with renal abscess formation.</p><p><b>CONCLUSION</b>CT is useful in evaluating enteric fever in patients with severe forms of presentation, a longer clinical course or less specific symptoms. Although the imaging features overlap with other abdominal infections, when combined with clinical features, travel history to endemic areas and presence of transaminitis, the diagnosis of enteric fever should be considered. CT in particular, is useful for the detection of complications such as perforation, bleeding and abscess formation.</p>

Antimicrobial resistance in typhoidal salmonellae.

Infections with Salmonella are an important public health problem worldwide. On a global scale, it has been appraised that Salmonella is responsible for an estimated 3 billion human infections each year. The World Health Organization (WHO) has estimated that annually typhoid fever accounts for 21.7 million illnesses (217,000 deaths) and paratyphoid fever accounts for 5.4 million of these cases. Infants, children, and adolescents in south-central and South-eastern Asia experience the greatest burden of illness. In cases of enteric fever, including infections with S. Typhi and S. Paratyphi A and B, it is often necessary to commence treatment before the results of laboratory sensitivity tests are available. Hence, it is important to be aware of options and possible problems before beginning treatment. Ciprofloxacin has become the first-line drug of choice since the widespread emergence and spread of strains resistant to chloramphenicol, ampicillin, and trimethoprim. There is increase in the occurrence of strains resistant to ciprofloxacin. Reports of typhoidal salmonellae with increasing minimum inhibitory concentration (MIC) and resistance to newer quinolones raise the fear of potential treatment failures and necessitate the need for new, alternative antimicrobials. Extended-spectrum cephalosporins and azithromycin are the options available for the treatment of enteric fever. The emergence of broad spectrum β-lactamases in typhoidal salmonellae constitutes a new challenge. Already there are rare reports of azithromycin resistance in typhoidal salmonellae leading to treatment failure. This review is based on published research from our centre and literature from elsewhere in the world. This brief review tries to summarize the history and recent trends in antimicrobial resistance in typhoidal salmonellae.

Occurrence & antibiogram of Salmonella Typhi & S. Paratyphi A isolated from Rourkela, Orissa.

Background & objectives: Almost round-the-year occurrence of Salmonella Typhi and Salmonella Paratyphi A has been noticed in Rourkela since last 13 and five years respectively. The incidence of infection along with the antibiogram of these two serotypes in this area were carried out. Methods: The study was carried out at Ispat General Hospital, Rourkela, India, between January 2005 and December 2008 with 5340 blood samples collected from patients with suspected enteric fever and pyrexia of unknown origin. Isolation, identification and antibiogram of the causative organisms were performed according to standard bacteriological procedures. Results: A total of 298 Salmonella isolates showed an overall per cent positivity of 5.58. Multidrug resistance was found in 11.96 per cent and 15.62 per cent isolates of S. Typhi and S. Paratyphi A respectively. Less than 2 per cent isolates of Salmonella showed resistance to ciprofloxacin. A resistance of 3.0 to 6.25 per cent against third generation cephalosporins was observed among the salmonella isolates. Interpretation & conclusion: A round-the-year occurrence of Salmonella spp. in Rourkela might have been due to the presence of a considerable number of carriers in the locality, poor sanitation in nearby slum areas, and inadequate and contaminated community water supply at times. Higher degree of susceptibility among S. Typhi isolates against various antibiotics was encouraging, but increasing trend of resistance observed among S. Paratyphi A isolates was a matter of concern.

Evaluation of the current trend of nalidixic acid susceptibility in typhoidal Salmonellae; a marker of therapeutic failure for the fluoroquinolones

Typhoid is a major health problem faced by the developing countries like Pakistan. More than 20 million cases are reported annually worldwide. Currently fluoroquinolones are the drugs of choice to treat typhoid fever. In vivo resistance to fluoroquinolones leading to therapeutic failure is developing rapidly and is becoming a major concern for the clinicians. The objective of this study was to determine the sensitivity pattern of Nalidixic acid over the last four years. A descriptive cross sectional study was carried out at the Microbiology Department of the Army Medical College, National University of Sciences and Technology, Rawalpindi from January 2006 to December 2009. All the isolates were dealt with standard microbiological procedures. The antimicrobial sensitivity of Nalidixic acid and Ciprofloxacin was determined using Kirby-Bauer disc diffusion method as per the guidelines of Clinical and Laboratory Standard Institute [CLSI]. Out of 240 isolates, 111 were Salmonella typhi and 129 were Salmonella paratyphi A. The resistance of the typhoidal Salmonella to Nalidixic acid has reached significant levels and it seems only a matter of time when hundred percent resistance will be encountered. All isolates were sensitive to Ciprofloxacin on disc diffusion method. Resistance to Nalidixic acid predicting therapeutic failure with fluoroquinolones is on a steady rise

Multilocus sequence typing and pulsed-field gel electrophoresis analysis of Salmonella Paratyphi A isolates from 2000 to 2008, China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze molecular and evolution characteristics of Salmonella Paratyphi A isolates from 2000 to 2008, China.</p><p><b>METHODS</b>Using pulsed-field gel electrophoresis (PFGE) method with SpeI restriction enzyme, and multilocus sequence typing (MLST) method based on housekeeping genes (aroC, thrA, hisD, purE, sucA, dnaN, hemD, adk, and purA), the genomic variations of 118 Salmonella Paratyphi A isolates from 10 regions during 2000 to 2008 were analyzed.</p><p><b>RESULTS</b>Using PFGE method, 118 Salmonella Paratyphi A isolates were clustered into 32 PFGE patterns, and 5 patterns were predominant (5 isolates or above). However, only 2 MLST types were identified for all isolates with MLST method. Among all Salmonella Paratyphi A isolates, the sequences of housekeeping genes were highly conservative and showed a high degree of cloning.</p><p><b>CONCLUSION</b>For Chinese epidemic Salmonella Paratyphi A isolates during 2000 - 2008, MLST method showed low discrimination power and the MLST method should not be applied to outbreak and epidemiological surveillance of Salmonella Paratyphi A. Currently, nationwide paratyphoid fever epidemics is caused by highly clonal isolates in China. As the time changes, these isolates also accumulate sporadic mutations.</p>

Isolation of Salmonella paratyphi A from renal abscess.

Intrarenal abscesses remain a significant cause of morbidity and mortality as well as a diagnostic dilemma because a plethora of microorganisms can cause this condition. A definitive diagnosis is made by demonstrating the organisms from the aspirate and the success or failure of therapy depends upon the antimicrobial sensitivity pattern. Enteric fever is a multisystem disorder caused by invasive strains of salmonella. Salmonellosis continues to be a major public health problem, especially in developing countries. Classic enteric fever is caused by S. typhi and usually less severe enteric fevers are caused by S. paratyphi A, B, or C. However, at times S. paratyphi is capable of causing serious and often life-threatening infections like infective endocarditis, pericarditis, empyma, sino-venous thrombosis, osteomyelitis, meningitis, bone marrow infiltration, hepatitis and pancreatitis. There are anecdotal case reports in world literature of abscesses being caused by this organism. Renal involvement like bacteriuria, nephrotic syndrome and acute renal failure have been reported due to S. parayphi A. S. paratyphi A has never been implicated in renal abscess, we report one such case that was managed successfully with medical therapy.

An increase in enteric fever cases due to Salmonella Paratyphi A in & around Chandigarh.

BACKGROUND & OBJECTIVE: Enteric fever is a major public health problem in India. It is classically caused by Salmonella enterica serotype Typhi. Salmonella enterica serotype Paratyphi A which had been reported less frequently from cases of enteric fever has shown an increasing trend since 1996 in India. There is also variation in the antimicrobial susceptibility of Salmonella Paratyphi A from different parts of the country. An attempt is therefore made to study the rate of isolation and antimicrobial susceptibility pattern of Salmonella Paratyphi A from cases of enteric fever coming to a tertiary care hospital at Chandigarh. METHODS: The blood samples of patients suspected of having enteric fever and admitted to Government Medical College and Hospital, Chandigarh, from January 2006 to April 2007 (11,240) were processed by conventional methods. Antimicrobial susceptibility was tested by Kirby-Bauer disc diffusion method. The minimum inhibitory concentration to two antibiotics- ciprofloxacin and chloramphenicol was determined by agar dilution technique. Simultaneously, retrospective analysis was done from January 2003-December 2005 to study any difference in the incidence and antimicrobial susceptibility pattern of Salmonella Paratyphi A among enteric fever patients. RESULTS: Of 305 total isolates, 231 were S. Typhi and 84 S. Paratyphi A rise. The number of Salmonella Paratyphi A cases rose from 27 in 2006 (34.18%) to 13 (40.63%) in four months of 2007. All were sensitive to ciprofloxacin and cefotaxime but MIC to ciprofloxacin was raised (0.125-0.5 microg/ml). Resistance to nalidixic acid was 92.5 per cent. Chloramphenicol sensitivity re-emerged with 90 per cent isolates sensitive to it while sensitivity to ampicillin dropped (72.5%) as compared to previous years. Only one isolate was multi-drug resistant. INTERPRETATION & CONCLUSION: The present study conferencing Salmonella Paratyphi A as the rapidly emerging pathogen of enteric fever. With increasing resistance to fluoroquinolones and possibility of re-emergence of sensitivity to chloramphenicol, the policy of empirical treatment of enteric fever needs to be rationalized.