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Bacteria
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Systemic infections caused by Salmonella typhi usually occur as a result of transmission from asymptomatic human carriers of S. typhi, who contaminate food or water. The classical example of a healthy carrier of S. typhi was “Typhoid Mary,” a cook who infected members of the families who employed her. Salmonella typhi invades the intestinal epithelial cells, passing from these into the lymphatic system and then is disseminated throughout the body by the vascular system. Although S. typhi is rapidly ingested by neutrophils and macrophages, the bacteria are not killed but rather multiply in these phagocytic cells. Systemic disease including high fever results from the reaction of the body to the widely disseminated organisms. Infection is established in cells in organs such as the kidney, liver, spleen, gall bladder, and the Peyer′s patches or lymph nodules of the intestine. It is these infected cells that harbor the S. typhi in carriers and serve as the reservoir for the microorganism between epidemics.
Immunosuppressants, rheumatic and gastrointestinal topics
Published in Evelyne Jacqz-Aigrain, Imti Choonara, Paediatric Clinical Pharmacology, 2021
Evelyne Jacqz-Aigrain, Imti Choonara
In developed countries, only 10 to 15% of cases of diarrhoea are due to bacteria. The use of antibiotics increases the cost of treatment and may prolong the disease. In some situations it may increase the duration of carrier state (e.g. salmonella infection) and increases the risk of secondary disease such as haemolytic uraemic syndrome in enterohaemorrhagic E. Coli. Recommendations for the use of antibiotics are based on the virulence of the microorganism and the clinical context. Antibiotic treatment is always indicated in salmonella typhi or paratyphi, shigella, and invasive amoebiasis. Other agents have a relative indication depending on the clinical context such as prolonged course of disease caused by E. Coli, salmonella infections in very young children, yersinia infection in patients with sickle cell disease, or severe bacterial diarrhoea in immuno-compromised children. Ceftriaxone is recommended (50 to 80 mg/kg/d) but ciprofloxacin may also be used [6].
Salmonella Carriage
Published in Firza Alexander Gronthoud, Practical Clinical Microbiology and Infectious Diseases, 2020
Salmonella species are subdivided into subspecies which can cause typhoid and paratyphoid fever, invasive nontyphoidal Salmonella (NTS) disease or non-invasive NTS disease. Immunocompromised individuals such as individuals living with HIV are especially at risk of extra-intestinal disease or relapses. Salmonella infection can be complicated by prolonged shedding in the stool and Salmonella Typhi infection may be complicated by a chronic carriage state. It is less clear if nontyphoidal Salmonella species can cause a chronic carriage state, as this is a less well studied area. It is therefore worthwhile to consider the following.
Alpha-1 antitrypsin deficiency: current therapy and emerging targets
Published in Expert Review of Respiratory Medicine, 2023
Oisín F. McElvaney, Daniel D. Fraughen, Oliver J. McElvaney, Tomás P. Carroll, Noel G. McElvaney
The pathogenesis of the lung and liver disease associated with AATD is different, therefore a single therapeutic approach aimed at both organs is rare. The initial concept was that enhancing secretion of Z AAT from hepatocytes would increase plasma and lung concentrations of AAT, while simultaneously relieving liver stress. Intravenous administration of Salmonella typhi increased serum AAT in people with ZZ AATD but that approach was not considered viable as a long term therapeutic option [114]. Synthetic estrogen such as diethylstilbestrol can stimulate hepatocytes to increase secretion of AAT in MM individuals but not in ZZ individuals [115]. Potential for use was further hampered by the associated estrogenic side effects. Later, a synthetic androgen, danazol was evaluated in this context. Danazol did increase AAT secretion in people with ZZ AATD but only by approximately 37% over pre-treatment levels [116]. None of these therapeutic approaches were evaluated for their effects on AATD liver disease and may have the potential to exacerbate liver symptoms.
Improving empiric antibiotic prescribing in pediatric bloodstream infections: a potential application of weighted-incidence syndromic combination antibiograms (WISCA)
Published in Expert Review of Anti-infective Therapy, 2022
Aislinn Cook, Mike Sharland, Yasmine Yau, PediBSI Group*, Julia Bielicki
For susceptibility to 3GC (e.g. cefotaxime, ceftriaxone): Number of ESBL-producing isolates was used where reported (Klebsiella spp., E. coli, and Enterobacter spp.);0% susceptibility due to intrinsic resistance in Acinetobacter spp., Pseudomonas spp., Enterococcus spp.;Assumed 100% susceptibility for Salmonella Typhi, non-typhoidal Salmonella spp., GAS, S. pneumoniae and H. influenzae;For Citrobacter spp., Serratia spp., Proteus spp., Raoultella spp. assumed same proportion susceptible as reported for Klebsiella spp.; andAll reported methicillin-susceptible S. aureus (MSSA) were assumed susceptible.
Recent strategies driving oral biologic administration
Published in Expert Review of Vaccines, 2021
Badriyah Shadid Alotaibi, Manal Buabeid, Nihal Abdalla Ibrahim, Zelal Jaber Kharaba, Munazza Ijaz, Ghulam Murtaza
Some pathogens could be mimicked by utilizing viruses and bacteria as vectors showing recombinant antigen expression. Such pathogens may infect GIT naturally and undergo colonization in the mucosa. These vectors could be exclusively helpful for the oral delivery of vaccines. The representative examples of such bacteria are Escherichia coli and Salmonella typhi, while the extensively studied viral vectors include adenovirus and poxvirus [110–114]. Several problems are associated with Salmonella typhi as a delivery tool in humans [110]. As the recombinant adenoviruses (rAd) have the promising capability to cause infection and undergo replication, several studies have reported their use as a vector for vaccine delivery to the intestine [114], sublingual mucosa [115], and intramuscular sites. According to vaccinological studies, rAd induced both antiviral humoral and cellular immunity in the clinical setup [116]. Nonetheless, the development of natural antibodies against various rAds has limited their use for systemic immunization. Contrary to it, the natural immune response does not affect the oral administration of rAds, revealing the usefulness of this route in adenoviral immunization.