Non-typhoid Salmonella bacteraemia in Greater Copenhagen 1984 to 1988

Characteristics of non-typhi Salmonella gastroenteritis associated with bacteremia in infants and young children

PURPOSE

To characterize the clinical and laboratory manifestations of non-typhi Salmonella gastroenteritis associated with bacteremia in children less than 36 months old.

METHODS

The study group included 17 patients, aged 2-34 months, with non-typhi Salmonella gastroenteritis and bacteremia, hospitalized in a tertiary pediatric medical center during the period 1995-2010. Clinical data were collected by medical chart review. Culture-related data were taken from the microbiology laboratory files. The results were compared with an assigned, age-matched, control group of 17 infants hospitalized with non-typhi Salmonella gastroenteritis without bacteremia.

RESULTS

Eleven cases (65%) occurred during the summer season. All patients presented with diarrhea, usually mixed with blood or mucus (clinical dysentery 65%). All but one had a high-grade fever (average 39.5°C). Three patients (19%) experienced convulsions during the acute episode of gastroenteritis. None of the patients had been previously treated with antibiotics. The most prevalent Salmonella serotype identified in the stool and blood was group C. Toxic appearance and convulsions on admission were more common among children with non-typhi Salmonella bacteremia, as opposed to those with non-typhi Salmonella gastroenteritis alone. No other epidemiological or laboratory differences were found.

CONCLUSIONS

Non-typhi Salmonella gastroenteritis poses a risk of bacteremia not only in infants younger than 3 months of age, but also in children younger than 36 months of age.

International travel and the risk of hospitalization with non-typhoidal Salmonella bacteremia. A Danish population-based cohort study, 1999-2008

Background

Information is sparse regarding the association between international travel and hospitalization with non-typhoidal Salmonella bacteremia. The aim of this study was to determine the proportion, risk factors and outcomes of travel-related non-typhoidal Salmonella bacteremia.

Methods

We conducted a 10-year population-based cohort study of all patients hospitalized with non-typhoidal Salmonella bacteremia in three Danish counties (population 1.6 million). We used denominator data on Danish travellers to assess the risk per 100,000 travellers according to age and travel destination. We used patients contemporaneously diagnosed with travel-related Salmonella gastroenteritis as reference patients to estimate the relative risk of presenting with travel-related bacteremia as compared with gastroenteritis. To evaluate clinical outcomes, we compared patients with travel-related bacteremia and patients with domestically acquired bacteremia in terms of length of hospital stay, number of extraintestinal focal infections and mortality after 30 and 90 days.

Results

We identified 311 patients hospitalized with non-typhoidal Salmonella bacteremia of whom 76 (24.4%) had a history of international travel. The risk of travel-related bacteremia per traveller was highest in the age groups 15-24 years (0.8/100,000 travellers) and 65 years and above (1.2/100,000 travellers). The sex- and age-adjusted relative risk of presenting with bacteremia was associated with travel to Sub-Saharan Africa (odds ratio 18.4; 95% confidence interval [6.9-49.5]), the Middle East (10.6; [2.1-53.2]) and South East Asia (4.0; [2.2-7.5]). We found high-risk countries in the same three regions when estimating the risk per traveller according to travel destination. Patients hospitalized with travel-related bacteremia had better clinical outcomes than patients with domestically acquired bacteremia, they had a shorter length of hospital stay (8 vs. 11 days), less extraintestinal focal infections (5 vs. 31 patients) and a lower risk of death within both 30 days (relative risk 0.2; [0.1-0.7]) and 90 days (0.3; [0.1-0.7]). A healthy traveller effect was a plausible explanation for the observed differences in outcomes.

Conclusions

International travel is a notable risk factor for being hospitalized with non-typhoidal Salmonella bacteremia and the risk differs between age groups and travel destinations. Healthy travellers hospitalized with bacteremia are less likely to have poor outcomes than patients with domestically acquired bacteremia.

Epidemiologic attributes of invasive non-typhoidal Salmonella infections in Michigan, 1995–2001

OBJECTIVES

To determine: (1) the incidence of invasive salmonellosis, (2) the distribution of specific Salmonella serotypes associated with invasive disease, and (3) the role of demographic characteristics in invasive salmonellosis in Michigan.

DESIGN

We conducted a cross-sectional study using laboratory-confirmed cases of salmonellosis reported to the Michigan Department of Community Health between 1995 and 2001.

METHODS

Average annual incidences (AAIs) for invasive salmonellosis were computed, and Poisson regression analysis was used to model the association between demographic attributes and invasive salmonellosis.

RESULTS

Of 6797 cases of salmonellosis, 347 (5.1%) were characterized as invasive having an AAI of 0.5/100000. A covariate-adjusted Poisson model showed children aged <1 year to be at higher risk for invasive salmonellosis compared to adults aged 40-49 years (rate ratio (RR) 8.98, 95% confidence interval (CI) 5.69-14.17). No significant differences were found between males and females (RR 1.02, 95% CI 0.83-1.26), African-Americans and Caucasians (RR 0.95, 95% CI 0.64-1.42), and urban and rural residents (RR 0.98, 95% CI 0.76-1.26). Among the most common serotypes associated with invasive salmonellosis (Heidelberg, Typhimurium, and Enteritidis), Salmonella serotype Heidelberg had the highest blood invasiveness ratio (15.79/100).

CONCLUSIONS

Children aged <1 year, especially of minority groups, are at higher risk for invasive Salmonella infections. Invasive salmonellosis may be included in the differential diagnosis of acute bacterial infections in young children with positive stool cultures for Salmonella.

A Case Report of Endovascular Stenting in Salmonella Mycotic Aneurysm: A Successful Procedure in an Immunocompromised Patient

Introduction: Mycotic aneurysms are associated with high mortality rates and are managed in the local setting with extra-anatomical bypass followed by ligation, exclusion and debridement of the aneurysm. This is the first case of successful endovascular stenting in an immunocompromised patient with Salmonella mycotic aneurysm. Clinical Picture: A middle-aged man who was HIV positive had Salmonella septicaemia. He developed abdominal pain 5 days after admission and a computed tomography (CT) scan of the abdomen revealed infrarenal aortitis. He developed a mycotic aneurysm 3 weeks later. Treatment: He opted for endovascular stenting and after prolonged antibiotic therapy and negative blood cultures, he underwent the procedure using a TalentTM stent, with an iliac extension. Outcome: He was discharged 1 week after stenting and maintained on oral bactrim based on sensitivity. At 1-year follow-up, he remains well symptomatically and CT scan showed no endoleak or collection. Conclusion: Endovascular stenting, though a fairly new procedure, can be successfully deployed even in a mycotic aneurysm in the right setting. Key words: Aortitis, Aortic aneurysm, Endovascular stenting, Salmonella enteriditis

Rupture of a nonaneurysmal aorta secondary to Staphylococcus aortitis

Infectious aortitis has become increasingly uncommon and, when diagnosed, typically occurs in an immunocompromised elderly male with a history of Staphylococcus or Salmonella infection and underlying atheromatous cardiovascular disease. The authors report a case of a 74-year-old man with aortitis complicated by rupture secondary to Staphylococcus aureus infection. The patient presented with worsening abdominal pain and fever after being discharged from the emergency room 2 weeks before with back pain and leukocytosis diagnosed as urinary tract infection and bronchitis. Computed tomography (CT) imaging of the retroperitoneum on the first visit appeared normal. Repeat CT scan on the subsequent visit revealed a contained rupture of a nonaneurysmal aorta at the level of the diaphragm. The patient was taken to the operating room emergently for repair. An infected periaortic hematoma and a 1 cm perforation in the posterior aorta were found. The aorta was excised and the area debrided. Revascularization was performed using a 22 mm extruded polytetrafluoroethylene (ePTFE) interposition graft placed in situ. This case demonstrates that a high index of suspicion is required in diagnosing infectious aortitis and that the diagnosis may be delayed in many cases. Additionally, it may not be uncommon for the infected aorta to rupture without prior aneurysm formation.

Incidence and prognosis of non-typhoid Salmonella bacteraemia in Denmark: a 10-year county-based follow-up study

The aim of this study was to examine the incidence and prognosis of non-typhoid Salmonella bacteraemia in a well-defined population in which complete follow-up investigations had been performed. All patients with non-typhoid Salmonella bacteraemia from 1994 through 2003 in North Jutland County, Denmark, were eligible for the study. Annual incidence rates were calculated for 10-year age groups. The North Jutland County Bacteraemia Database (inclusion of subjects), medical hospital records, the Prescription Registry (redemption of prescription drugs), and the Central Population Registry (deaths) were used as data sources. The outcomes were mortality within 30 and 180 days of the first non-typhoid-Salmonella-positive blood sample. Cox proportional-hazards regression analysis was performed, first with age and comorbidity as evidenced by Charlson index scores, and second with selected clinical and laboratory prognostic variables potentially related to non-typhoid Salmonella bacteraemia per se. A total of 111 non-typhoid Salmonella bacteraemia patients were included in the study. The incidence rate (mean 2.3/100,000 person-years) increased steadily from 1.9/100,000 person-years in the 40-49-year age group to 14.6/100,000 person-years in those >90 years. Twelve (11%) and 24 (22%) patients died within 30 and 180 days, respectively. Cox regression analyses showed that increasing age and, to a higher degree, increasing levels of comorbidity were independently associated with an unfavourable outcome, whereas none of the clinical or laboratory variables studied were strong independent prognostic factors. In conclusion, the presence of comorbid diseases and old age were independently associated with mortality, whereas clinical and laboratory variables were less important.

Important bacterial gastrointestinal pathogens in children: a pathogenesis perspective

This article focuses on the five most common bacterial enteropathogens of the developed world--Helicobacter pylori, Escherichia coli, Shigella, Salmonella, and Campylobacter--from the perspective of how they cause disease and how they relate to each other. Basic and recurring themes of bacterial pathogenesis, including mechanisms of entry, methods of adherence, sites of cellular injury, role of toxins, and how pathogens acquire particular virulence traits (and antimicrobial resistance), are discussed.

Risk factors for development of nontyphoid Salmonella bacteremia

The objective of this paper was to identify risk factors for nontyphoid Salmonella bacteremia by making a retrospective chart review of 39 patients with nontyphoid Salmonella bacteremia. The control group included 30 patients with positive Salmonella stool culture (gastroenteritis group). Demographic factors, presenting signs and symptoms, antimicrobial treatment before admission, and microbiologic results were recorded. Nine patients (23%) were excluded owing to recognized risk factors for development of extraintestinal disease. Seventeen cases (57%) occurred during summer time, whereas the gastroenteritis group had a less seasonal tendency. Eighty percent of the patients with Salmonella bacteremia had a previous history of diarrhea. At admission more patients in the bacteremia group were febrile and had leukocytosis (73% vs 33% and 37% vs 20%, respectively). More patients in the bacteremia group had previous antibiotic treatment (57% vs 20%, p<0.01). The Salmonella types were mainly C and D in the bacteremia group (40% each), and B and C in the gastroenteritis group (26% and 52%, respectively). The risk factors for Salmonella bacteremia in previously healthy children include warm season, previous gastrointestinal illness, and preexposure to antibiotics.

Clinical review of nontyphoid Salmonella infections from 1991 to 1999 in a Danish county

To determine outcomes of nontyphoid Salmonella infections, we reviewed all 3328 cases of infection registered in a large Danish county from 1991 to 1999. The hospitalization rate was 27% among patients <5 years old, 22% among patients 5-59 years old, and 54% among patients > or =60 years old; complications were present in 7% and extraintestinal disease in 4% of patients. We conclude that nontyphoid Salmonella infections may frequently cause severe disease even among patients without predisposing conditions.

Increasing incidence of nontyphi Salmonella bacteremia among children living in southern Israel

OBJECTIVES

To determine if the epidemiology of Salmonella gastroenteritis and childhood bacteremia among the two ethnic populations (Jews and Bedouins) living in southern Israel has changed in recent years.

METHODS

Retrospective review of laboratory records and medical charts of patients from whom non-typhi salmonellae were isolated from stool and blood cultures in the 1990-1995 period.

RESULTS

The overall incidence of enteric Salmonella infections was 123.5 per 100 000 inhabitants and remained stable during the study period. The incidence of bacteremia among children younger than 4 years increased from 9.3 per 100 000 in the 1990-1992 period to 26.8 per 100 000 in the 1993-1995 period (P 0.01). This increment was especially caused by Salmonella virchow and S. enteritidis, which were also isolated with increasing frequency from stool cultures. The Bedouin population was underrepresented among stool isolates, whereas its representation among blood isolates closely resembled the fraction of this ethnic group in the overall population of the area.

CONCLUSIONS

The incidence of enteric salmonellosis has remained stable at a high endemic level in recent years in southern Israel. The incidence of children's bacteremia has experienced a significant increase, associated with S. virchow and S. enteritidis. Differences in the utilization of medical services may explain differences in the epidemiology of Salmonella infections found in the two resident ethnic groups.

Salmonella dublin infection: a rare cause of spontaneous bacterial peritonitis and chronic colitis in alcoholic liver cirrhosis

Salmonella dublin is a veterinary pathogen which rarely causes human illness, although reported human isolates have increased over the past two decades. This serovar of salmonella is unusually invasive and life-threatening, although the clinical pattern of human infection is not well known. We describe a 51-year-old cirrhotic patient who presented with severe liver failure, chronic diarrhoea and left-sided segmental colitis. Radiological and endoscopic findings suggested Crohn's colitis. During the hospital stay he developed a spontaneous bacterial peritonitis (SBP) and S. dublin was isolated in the ascitic fluid. Our report supports the view that this salmonella serovar should be kept in mind as a rare cause of SBP in cirrhotic patients, especially in those cases with chronic colitis resembling Crohn's disease.

Non-typhoidal Salmonella bacteraemia without gastroenteritis: a marker of underlying immunosuppression. Review Of cases at St. Thomas' Hospital 1970-1999

OBJECTIVES

To classify non-typhoidal salmonella bacteraemia according to clinical presentation, and to study how this correlates with the presence of underlying immunosuppression.

METHODS

We analysed data collected prospectively for all 82 cases of non-typhoidal salmonella bacteraemia presenting to St. Thomas' Hospital between 1970 and 1999.

RESULTS

Patients presented with one of three syndromes: diarrhoea, an extra-intestinal focus of infection, or isolated fever with no focus. Only 18% of those with diarrhoea had underlying immunosuppression, compared with 80% of those with extra-intestinal focal infections (P= 0.001) and 80% of those with no focus (P= 0.0001). There was no significant association between salmonella serotype and underlying immunosuppression. Salmonella enteritidis isolates, especially phage type 4, increased significantly during the last decade (P= 0.001). The presentation of non-typhoidal salmonella bacteraemia in the absence of diarrhoea prompted the diagnosis of HIV in two patients.

CONCLUSION

Underlying immunosuppression should be excluded in patients presenting with non-typhoidal salmonella bacteraemia in the absence of gastroenteritis. This may lead to an earlier diagnosis of HIV.

Impact on human health of Salmonella spp. on pork in The Netherlands and the anticipated effects of some currently proposed control strategies

The impact on human health of Salmonella spp. on pork in The Netherlands is described. Subsequently, the effects of some currently proposed control strategies in the Dutch pork production chain are evaluated and quantified with the aid of a simple mathematical model. The estimated average incidence of cases of salmonellosis in the Netherlands is about 450 cases per 100,000 person years at risk (pyar). Some special risk groups for which the risks could be quantified are (1) persons with underlying diseases, such as neoplasms or diabetes mellitus (1200 cases/100,000 pyar); (2) persons with achlorhydria or who excessively use antacids (1100 cases/100,000 pyar); (3) persons who have recently been treated with antibiotics that disturb the normal gut flora (1700 cases/100,000 pyar); (4) nurses (900 cases/100,000 pyar); (5) caterers (900 cases/100,000 pyar); (6) slaughterline personnel (1800 cases/100,000 pyar). Furthermore, it is estimated that 15% (5-25%) of all cases of salmonellosis in The Netherlands are associated with the consumption of pork. Currently, proposed control measures regarding Salmonella in pigs and on pork in The Netherlands are codes of good manufacturing practices (GMP) that, in fact, formalize recommendations that can be found in many handbooks about pig breeding and pig slaughtering. When evaluated by a mathematical model constructed for this purpose, the proposed GMP codes from farm to cutting/retail could, at best, reduce the current levels of Salmonella-positive pigs and pork by 50-60%. If pigs were bred according to the rather costly specific pathogen-free concept (SPF), the prevalence of contaminated carcasses and pork could in total be reduced by 95% or more. However, implementing GMP codes from the transport phase up to the cutting/retail phase coupled with a decontamination step at the end of the slaughterline would be just as effective as GMP in combination with breeding using the SPF-concept. It is therefore concluded that the most efficient and cost-effective way of reducing the 'Salmonella problem' entailed by the consumption of pork would be to decontaminate carcasses under the precondition that the entire production chain strictly adheres to GMP principles. Therefore, the EU should also allow for more possibilities regarding the decontamination of carcasses than is currently the case. It is also concluded that current EU regulations relying on hazard analysis of critical control points (HACCP)-inspired production in cutting plants will not be effective in reducing the prevalence of Salmonella spp. on pork. This is mainly because (1) there is currently an almost steady stream of Salmonella-positive carcasses that enter the cutting process; (2) when contaminated carcasses are being processed, further cross-contamination during working hours is unavoidable; (3) no steps in the cutting process are intentionally designed to effectively reduce the risks or consequences of cross contamination of cuts and retail-ready products.

Extraintestinal salmonellosis in a general hospital (1991 to 1996): relationships between Salmonella genomic groups and clinical presentations

Episodes of extraintestinal salmonellosis treated at a general hospital (1,522 beds) over a 6-year period (1991 to 1996) were characterized by the analysis of phenotypic and genotypic traits of Salmonella organisms and clinical data from medical reports. Extraintestinal salmonellosis accounted for 8% of all salmonellosis episodes. Fifty-two medical reports, dealing with 6 cases of typhoid fever, 32 cases of bacteremia, and 14 focal infections, were reviewed. All cases of typhoid fever except 1, 7 cases of bacteremia, and 5 focal infections were not related to any underlying disease or predisposing factors, while 25 cases of bacteremia and 9 focal infections were associated with some of these risk factors. All typhoid isolates and 65.4% of the nontyphoid isolates were susceptible to antimicrobials. Fifty-one nontyphoid strains were analyzed and assigned to 21 genomic groups, which were defined by serotype, combined ribotype, and combined randomly amplified polymorphic DNA type (each genomic group could include organisms differing in some phenotypic traits). The relationships between genomic groups and clinical presentations were traced. Organisms causing 22 episodes (17 episodes of bacteremia, 2 of pneumonia, 1 of peritonitis, 1 of pyelonephritis, and 1 of cystitis) belonged to a prevalent Salmonella enterica serotype Enteritidis genomic group, which included organisms assigned to four phage types, five biotypes, and four resistance patterns, causing infections in patients with and without risk factors. Seven other genomic groups, 4 Enteritidis groups (associated with both bacteremia and focal infections), 2 Typhimurium groups (one associated with bacteremia and the other with focal infections) and 1 Brandenburg group (associated with bacteremia) included two or more strains, and the remaining 13 genomic groups consisted of only one strain each.

Non-typhoidal Salmonella bacteraemia: clinical features and risk factors

A case control study was conducted to determine the risk factors of non-typhoidal Salmonella bacteraemia. Eighty adult patients with non-typhoidal Salmonella bacteraemia admitted to Siriraj Hospital from January to December 1993 served as the cases. The controls comprised 3 groups: group 1, 80 adult in-patients with Escherichia coli bacteraemia; group 2, 80 adult in-patients who did not have bacteraemia and had been admitted to the hospital during the same period as the cases; group 3, 80 in-patients who did not have Salmonella bacteraemia and matched the cases in terms of gender, age, hospital services and admission date. AIDS and corticosteroid use were the major risk factors for acquiring non-typhoidal Salmonella bacteraemia with an odds ratio of 7.27 to 12.31 (95% confidence interval of 3.39 to 29.40). Almost all patients with non-typhoidal Salmonella bacteraemia presented with a fever for a median duration of 7 days. AIDS patients usually had concomitant opportunistic infections. Salmonella group D was the most common serogroup. Most patients were treated with co-trimoxazole, quinolones, ceftriaxone and ampicillin. Localized suppurative complications were observed in 14% of the patients; the overall mortality rate was 36.3%, 12% of whom died prior to receiving appropriate antibiotics for Salmonella.

Neonatal Salmonella meningitis: two case reports

Two cases of neonatal Salmonella meningitis are reported. Both infants were seriously ill: one died 6 days after admittance to the hospital; the other required artificial ventilation for 4 days and recovered without sequelae. In both cases close relatives had shown signs of gastrointestinal infection just prior to the reported cases. The symptoms, the outcome and antibiotic treatment are discussed. In view of the increasing incidence of salmonella infections in Denmark and the serious prognosis of neonatal meningitis, it is important to consider the diagnosis in all cases of bacterial meningitis in infancy.

Evaluation and comparison of molecular techniques for epidemiological typing of Salmonella enterica subsp. enterica serovar dublin

A total of 28 unrelated isolates of the Salmonella enterica subsp. enterica serovar dublin (S. dublin) collected during a 6-year period, as well as four samples of the S. dublin live vaccine strain Bovisaloral and its prototype strain S. dublin 442/039, were investigated by different molecular typing methods for the following reasons: (i) to find the most discriminatory method for the epidemiological typing of isolates belonging to this Salmonella serovar and (ii) to evaluate these methods for their capacity to discriminate among the live vaccine strain Bovisaloral, its prototype strain S. dublin 442/039, and field isolates of the serovar dublin. Five different plasmid profiles were observed; a virulence plasmid of 76 kbp as identified by hybridization with an spvB-spvC gene probe was present in all isolates. The detection of 16S rRNA genes and that of IS200 elements proved to be unsuitable for the epidemiological typing of S. dublin; only one hybridization pattern could be observed with each of these methods. The results obtained from macrorestriction analysis strongly depended on the choice of restriction enzyme. While the enzyme NotI yielded the lowest discriminatory index among all enzymes tested, it was the only enzyme that allowed discrimination between the Bovisaloral vaccine strain and its prototype strain. In contrast to the enzymes XbaI and SpeI, which only differentiated among the S. dublin field isolates, XhoI as well as AvrII also produced restriction fragment patterns of the Bovisaloral strain and of its prototype strain that were not shared by any of the S. dublin field isolates. Macrorestriction analysis proved to be the most discriminatory method not only for the epidemiological typing of S. dublin field isolates but also for the identification of the S. dublin live vaccine strain Bovisaloral.

Changing epidemiology of human salmonellosis in Hong Kong, 1982-93

A comprehensive analysis of the epidemiology of salmonellosis in a major hospital in Hong Kong from 1982-93 is reported. The trend of salmonella isolations over the past 12 years and changes in the occurrence of individual serotypes are delineated. A total of 5328 isolates were analyzed. Groups B (Salmonella typhimurium and S. derby) and E (S. anatum) were the commonest serogroups isolated from the intestinal tract in all age groups. A significant increase in the isolation of group D salmonellae has been observed since 1989. This is accounted for by a substantial rise in S. enteritidis isolation as seen in Western countries, despite a concomitant decrease of S. typhi. The extraintestinal isolation index (EII) is proposed as an index of the virulence potential of individual serotypes and serogroups. Group D salmonella was found to be the most invasive serogroup. While group D was the predominant serogroup isolated from extraintestinal sites in patients older than 1 year, group B serotypes (especially S. typhimurium) were more frequently seen in infants younger than 12 months.

Genomic lineage of Salmonella enterica serovar Dublin

Thirty five strains of the host adapted Salmonella serotype Dublin (S. Dublin) have been characterized by IS200 patterns, ribotyping, pulsed-field gel electrophoresis (PFGE), restriction fragment polymorphism after hybridization with five randomly cloned DNA-fragments of S. enteritidis (RFLP), and plasmid profiling in order to divide the strains into 'genomic lines'. For comparison, 20 other strains of 9 different group-D serotypes were included. The IS200 patterns were identical in all strains of S. Dublin examined. These patterns were different from those observed in other group-D Salmonella with the exception of one strain S. Enteritidis phage type 11 and a strain of S. Rostock. The insertion element IS200 was not detected in strains of S. Dar-es-Salam, S. (II) 9,12:z:-, and S. Panama. RFLP, based on probing with five random cloned chromosomal fragments gave the same pattern in all strains except for one isolate from the UK. This strain was also found to have an unique PFGE pattern and ribotype. Among the remaining strains, three different PFGE patterns and 7 different ribotypes were observed. Based on all four typing methods, 8 different 'genomic lines' of S. Dublin were identified. The same grouping could be obtained from the use of ribotyping alone, but PFGE and RFLP were found to provide valuable information on possible relationships between ribotypes. Seven different plasmid profiles and a group of strains without plasmids were observed. In several cases, the same plasmid profile was shown to be present in more than one 'genomic line'.

Abscess of the submandibular gland caused by Salmonella typhimurium biotype 10

From an abscess of the submandibular gland, Salmonella typhimurium biotype 10 was isolated in pure culture. The patient had no history of gastroenteritis, and Salmonella could not be isolated from faeces.

Myonecrosis in the leg caused by Salmonella enteritidis

Five weeks after an episode of gastroenteritis, a 65-year-old diabetic male developed an extensive myonecrosis, with gas production in the left leg caused by Salmonella enteritidis. The patient was treated with surgical revision and antibiotics. To our knowledge, this is the first case of myonecrosis with gas production in a leg caused by Salmonella enteritidis, in which the patient survived, and the limb was saved.

Cerebral Salmonella typhimurium abscess in a patient with a stroke

A 59-year-old woman with renal failure was admitted in a coma with seizures. Computerized tomography (CT) revealed a frontal mass in the right cerebral hemisphere and on day 12 new low density areas had appeared in both the right and left hemisphere. Blood cultures on day 13 grew Salmonella typhimurium, and the patient died the next day. An autopsy showed cerebral infarction with abscess formation. The elusive features of non-typhoid Salmonella infections make it advisable to obtain blood and faecal cultures from susceptible patients with fever or focal disorders of unknown aetiology.

Antimicrobial resistance of Salmonella isolates in a Spanish hospital

We studied 961 clinical Salmonella isolates (one per patient) seen in one Spanish hospital from 1988 to 1991. The incidence of non-Salmonella typhi Salmonella infections per 100,000 admissions increased from 3.93 to 5.98. Overall rates of resistance to ampicillin, chloramphenicol, and co-trimoxazole were 32, 11, and 2%, respectively. Resistance to chloramphenicol increased from 9 to 16% during the study period, while resistance to each of the other drugs remained stable. Variations related to serogroups were observed.