What does salmonella typhimurium look like

Figure 8. Behavioral changes in mice infected with S. Typhoid patients manifest neurological symptoms during and even years after the disease incidence. This led us to investigate the behavior of infected mice after antibiotic Figure S1 treatment and the corresponding bacterial burden. While some mice showed a restoration in their ability to find the water maze platform, there were animals which were still strikingly incapable of performing the task.

Moreover, bacteria were still present in the brains of even the better performing mice Figures 9A—F. Figure 9. Neurological manifestations of Salmonella brain invasion and effect of antibiotics. B Time taken by the mice in A to swim to a platform in a water maze experiment pre and post-infection. D Time taken by the mice in C to swim to a platform in a water maze experiment pre and different stages post-infection. F Time taken by the mice in E to swim to a platform in a water maze experiment pre and different stages post-infection.

Each point in the plots represents an animal. Few animals died prior to the designated test days. These results could have serious implications in the general neurological health of the host in the long run. Salmonella infections are frequent in developing nations around the world.

Neuro-psychiatric symptoms related to typhoid fever have been observed for years Khosla et al. Alarmingly, multidrug resistant typhoid incidences have also been found to be associated with neurologic manifestations Lutterloh et al. While we have looked at S. Typhimurium infection in mice which mimics human typhoid fever, the effect of non-typhoidal infections in this regard cannot be ignored. Tracking and data collection regarding self-limitting gastrointestinal diseases would be considerably more challenging to understand the interaction with brain in that regard.

Consequently, reports are expected to be limiting Rizek et al. Recently, Bauler et al. Typhimurium burden in the brain Bauler et al. Our results corroborate the observations made by Bollen et al. Further, we observed an enhanced thickness of the granular layer in infected cerebellum. Enhanced granular layer thickness has been associated with age related degeneration and might be an important sign of neurological deficit Zhang et al.

Typhimurium genes like ompA and SPI-1 genes, that take part in mediating host brain invasion. Here, we show that ompA is essential for brain invasion by S. Apart from its structural roles, OmpA also serves a pathogen-associated molecular pattern in bacteria belonging to Enterobacteriaceae Jeannin et al. Besides its other roles, OmpA has been shown to be an important player in blood-barrier penetration of a number of bacteria especially E.

OmpA of C. Enterobacter sakazakii requires OmpA for invasion of brain endothelial cells via induction of microtubule condensation Singamsetty et al. The implications of Salmonella burden in various parts of the brain could be far reaching. Proliferation of the pathogen in various brain parts could be associated with an enormous variety of neurological symptoms.

Moreover, we found a very high proliferation capacity in neuronal cell lines bolstering our hypothesis that the neurological manifestations post-infection are effects of possible cell death or modulation in the brain. Further, cellular endotoxins are known to induce inflammation in substantia nigra dopaminergic neurons.

Hippocampal slice cultures were found to undergo neurodegeneration in presence of Salmonella LPS Johansson et al. Interestingly, sepsis has been found to make the blood-brain barrier leaky Brandtzaeg et al. Effects mediated by endotoxins could therefore lead to a battery of symptoms in context of the neurological manifestations.

Glial cells could also serve as a niche for Salmonella in the brain. Conceivably, Salmonella would be less proliferative in glial cells, however, they may act as a niche harboring persister populations. With the average life-span of humans getting extended every decade and the complexities in modern lifestyles, we are also witnessing an increase in the incidences of neurological abnormalities ranging from depression, anxiety, bipolar disorders to diseases like Parkinson's disease and Alzheimer's disease.

In view of the enhanced incidences, the possible causes such as external pathogens are of outstanding importance. With genetic predisposition to such conditions on one hand, such external agents as bacterial infections could be viewed with heightened seriousness and in turn avoided.

A recent report has drawn connections between Alzheimer's disease and Salmonella Kumar et al. Plaques were observed to be formed around the bacterial cells thereby entrapping them. Very conceivably, this phenomenon could easily steer toward an unpleasant outcome for the host in the absence of a very tight regulation.

This arena calls for a much greater understanding to actually unveil the cause and effect scenario of intracellular bacterial pathogens in the brain and allow active alleviation of the avoidable causes of neurological manifestations. Wild type WT S. Overnight cultures prepared from inoculation of a single colony from a fresh plate were used for infecting mice at the mentioned dosage.

Either overnight culture or subcultured bacteria were used for cell-line experiments. Briefly, the kanamycin resistance gene cassette was PCR amplified from pKD4 plasmid using specific primers which also carried sequences homologous to the flanking region of the target gene. The knockouts were confirmed using both primers against the gene of interest as well as Kan R cassette internal primers.

Michael Hensel. The murine macrophage cell line RAW A monolayer of respective cells was infected with either overnight or 0. Bacterial attachment to host cells was enhanced by centrifuging at —1, rpm for 5 min. Infected cells were lysed using 0. Fold Proliferation:. Percent invasion:. Percent invasion was calculated as: no. For immunofluorescence analysis, RAW At indicated time points post-infection, cells were washed with PBS and fixed with 3.

Post-washes, cells were then incubated with appropriate secondary antibody conjugated with fluorophores. Coverslips were mounted on a glass slide containing mounting medium.

Images were analyzed using the Zen software provided by Zeiss. Two strains of mice, 4—6 weeks old were used viz. Paratyphi are common in many developing countries where sewage and water treatment systems are poor. Most cases reported in BC are among travelers returning from those areas. Typhi are bacteria which infect the intestinal tract and the blood. Paratyphi A, B and C bacteria cause a similar illness which is included under the typhoid heading.

However, paratyphoid fever is generally milder and shorter in duration than typhoid fever. Paratyphi come from the same sources and are common in many developing countries where sewage and water treatment systems are poor. Typhi infection is serious and potentially life-threatening. Typhi may cause:. Symptoms start an average of 1 to 2 weeks range: 3 to 60 days, or longer after exposure to the bacteria.

If you think you have a S. Typhi infection, see your family doctor for testing, advice and treatment. Typhi is spread by the fecal-oral route. Fecal material from infected humans can get into our mouths in a variety of ways:. People who have recovered from illness may remain infectious to others about ten per cent of those recovered may pass the bacteria in their stools or urine for up to three months.

They are able to cause significant morbidity, and in some case, mortality, in both humans and animals. Explore the features of two closely related subspecies of the bacteria, Salmonella. Find out how the differences in their genomes results in their ability to cause two very different diseases. Staphylococcal infections are a group of infections caused by the bacterium Staphylococcus. Infection causes a range of symptoms, from skin conditions to food poisoning.

Streptococcal infections are any type of infection caused by the group of bacteria Streptococcus. Tuberculosis is a disease caused by a bacterium that mainly affects the lungs to cause a persistent and, occasionally bloody, cough. Infectious diseases are caused by microorganisms such as viruses, bacteria, fungi or parasites and can spread between individuals.

Antibiotic resistance is when bacteria develop the ability to survive exposure to antibiotics designed to kill them or stop their growth. It was found that a single strain containing a plasmid having multi drug-resistance has emerged in the S. With the current spread of Salmonella, researchers are looking for easier ways to detect typhoid fever in order to better treat patients. Another project has to do with dipstick assay which detects antibodies and analyzes the effect of typhoid fever in patients.

It found specific IgM antibodies on patients in Testing of serum samples from culture negative patients with a clinical diagnosis of typhoid fever resulted in staining of the dipstick in 4.

This shows the late development of antibodies in the blood for a large number of patients. The advantages of the dipstick assay are that the result can be obtained on the same day allowing a prompt treatment. No special laboratory equipment is really needed to perform the assay and one would only need a small amount of serum.

What makes it even better is that the simplicity of the assay would allow it to be used in places that lack laboratory facilities, such as third world countries that lack modern facilities and where disease is running high 9. More people have taken a greater interest in Salmonella typhi since the decreasing effects of antibiotics.

In , more research was done in order to find the global gene expression by Salmonella typhi during infection. Global expression profiles of typhi grown in vitro and within macrophages at different time points were obtained and studied.

The results concluded that Salmonella typhi had an increased expression of genes encoding resistance to antimicrobial peptides, which used the glyoxylate bypass for fatty acid utilization, and did not induce the SOS response or the oxidative stress response.

It was also found that genes coding for the flagellar apparatus, chemotaxis, and iron transport systems were down-regulated in vivo. This experiment allowed a better understanding of Salmonella and found a safer and more effective way to determine the bacterial transcriptome in vivo. This could possibly lead to the investigation of transcriptional profiles of other bacterial pathogens without the need to recover much bacterial mRNA from the host 7.

Journal of Bacteriology. Volume Nature Reviews Micriobiology. Volume 2. Kita, Hiroshi, and Nikaido Hiroshi.

Falkow, Stanley, Monack, Denise M. Nature Review of Micribiology.