Antibiotics for Amoeba

Amoebiasis can be defined as an acute or chronic inflammation that is caused by the parasitic amoeba, Entamebahistolitica. This is generally contracted by water and any prepared foods infected due to poor hygienic condition and that might cause contamination. It is featured by watery diarrhea, bloody stools and feverish conditions.

It has been already brought out that people having symptoms causing amebiasis are infected with a special microorganism called Entamoeba histolytica, and those patients who exhibit no symptoms are in reality, infected with almost very-looking amoeba known as Entamoeba dispar. During their life cycles, the amoebas live in two very different classes: the infective cyst or capsule form that is not mobile but can survive outside the human body as it has its protective covering and the disease-developing form, the trophozoite that though capable of to move, cannot survive once passed in the feces and, thus, cannot infect any other individuals.

Most of what we call antibiotics are molecules which interfere with the metabolism or reproduction of prokaryotes-bacteria.

Take penicillin for example.It interferes with the growth of the bacterial cell wall. This would not bother an ameba.

Antibiotics work to kill bacteria.Bacteria are single-cell organisms.If bacteria make it past our immune systems & start reproducing inside our bodies,they cause diseaseWe want to kill bacteria to eliminate disease.

Certain bacteria produce chemicals that damage or disable parts of our bodies. In an ear infection,for example,bacteria have gotten into inner ear.The body is working to fight bacteria,but immune system's natural processes produce inflammation.Inflammation in ur ear is painful.So u take an antibiotic to kill the bacteria & eliminate inflammation.

An antibiotic is a selective poison.It has been chosen so that it will kill the desired bacteria,but not the cells in ur body.Each different type of antibiotic affects different bacteria in different ways.For example,an antibiotic might inhibit a bacterium's ability to turn glucose into energy,or its ability to construct its cell wall.When this happens,the bacterium dies instead of reproducing.At the same time,the antibiotic acts only on bacterium's cell-wall-building mechanism,not on a normal cell's.

Antibiotics do not work on viruses because viruses are not alive.A bacterium is a living, reproducing lifeform.A virus is just a piece of DNA(or RNA).A virus injects its DNA into a living cell & has that cell reproduce more of the viral DNA.With a virus there is nothing to "kill,"so antibiotics don't work on it.

Yes,but only specific kinds of antibiotics will kill protozoa.Metronidazole can kill amoeba & Giardia I think.It kills by disrupting sensitive organism's DNA via helicase block.

Scientists have found that an antibiotic-resistant strain of Salmonella becomes especially virulent when tucked inside protozoa in rumen of cows.

In general you can use Antibiotics active against protozoa including metronidazole,trimethoprim-sulfamethoxazole, and quinine.

Larger parasites like tape worms & round worms can be treated effectively in a short time with chemical drugs & even some natural products.Mostly overlooked however,because of inadequate laboratory procedures, are Amoebas.

The immune suppressive toxins (lectins) of pathogenic amoebas such as Blastocystis hominis, Giardia lamblia, Entamoeba histolytica3 ,4, 5 can cause numerous symptoms which are not associated with parasites. Unfortunately, these lectins can affect the exact areas of the body where one already has a constitutional (genetic) weakness.

For example, Allergies, Arthritis, Asthma, or even nerve disorders can often be directly linked to parasite infections. Parasite infestations can also be completely asymptomatic. This does not make them less hazardous. It was also found that lectins can block the "neurotransmitter uptake" to the brain.

Amoeba antibiotic aims to destroy superbugs

Humble amoeba could be a new weapon for mankind in the battle against deadly superbugs.

A Scottish scientist has just been given a government grant to help his research into the potential of the single cell organism to produce a new type of antibiotic capable of defeating deadly bacteria such as MRSA and E coli 0157.

Dr Sutherland Maciver, a lecturer in biochemistry at Edinburgh University, had the idea after years spent observing the behaviour of amoeba under the microscope.

The organisms, about a 50th of a millimetre across, are efficient killers of bacteria, including strains which have become largely immune to antibiotics.

Treatment of Amoebiasis

Generally, amebiasis can be treated by antimicrobial medication; however, in severe cases such as amebic liver abscess hospitalization and surgery is required. In asymptomatic intestinal infection remedy, treatment using diloxanide furoate iodoquinol, paromomycin or metronidazol is quite common. In some milder cases, the condition can be treated with various natural herbs such as Emblica officinalis, belerica and Eclipta alba. Neem is also considered to be great disinfectant. One can use pills or decoction of those herbs in order to heal the diseases. Buttermilk is also considered to be good replacement therapy in Ayurveda.

In some more severe cases of amoebic dysentery, the treatment involves supplementation of IV fluids with lots of other medications such as antacids, anti-nauseant and anti-spasmodic; they are either given orally or by injections. In some serious cases, such as hepatic abscess, patient may require typical removal.

Antibiotic Susceptibilities of Parachlamydia acanthamoeba in Amoebae

Parachlamydia acanthamoeba are intracellular bacteria of amoebae and are considered potential etiological agents of human pneumonia. We have determined the in vitro antibiotic susceptibilities of two strains (strain Bn9 and Hall's coccus) in Acanthamoeba polyphaga. The two strains were susceptible to tetracyclines, macrolides, and rifampin, but resistant to fluoroquinolones.

Based on 16S ribosomal DNA sequence comparison, the taxonomic classification of species belonging to the order Chlamydiales has been recently reassessed, and a new family, Parachlamydiaceae, has been proposed. This family now comprises two genera: i.e., the genus Parachlamydia with Parachlamydia acanthamoeba as a type species, and the genus Neochlamydia with Neochlamydia hartmannellae as the type species. Strains belonging to the species P. acanthamoeba include the type strain Bn9 (ATCC VR 1476), isolate Berg17, Hall's coccus, and unnamed isolates (2, R. J. Birtles, T. J. Rowbotham, C. Storey, T. J. Marrie, and D. Raoult, Letter, Lancet 349:925-926, 1997), which are all strictly intracellular bacteria with variable Gram staining properties and which display more than 99% 16S rRNA gene similarity (Birtles et al., Letter). Parachlamydia spp. naturally infect Acanthamoeba. Trophozoites of Acanthamoeba hosting chlamydia-like bacteria have been isolated in patients with fever associated with use of humidifiers in Vermont (i.e., Hall's coccus) and from human nasal mucosa (i.e., the Bn9 and Berg17 strains). Moreover, fourfold rising titers of antibodies directed against Hall's coccus have been detected by an immunofluorescence technique in sera from patients suffering from pneumonia of undefined cause in Ohio and Nova Scotia, Canada (Birtles et al., Letter). These sera did not react with Chlamydia trachomatis, Chlamydophila pneumoniae, or Chlamydophila psittaci antigens (Birtles et al., Letter). More recently, Marrie et al. reported detection of anti-P. acanthamoeba antibodies (antibody titer of 179 [there] [there]? 121:50) in 8 of 376 patients (~2%) with community-acquired pneumonia compared with 0 of 511 healthy controls. Thus, a recent medical interest in Parachlamydia strains has arisen because of the potential etiological role in community-acquired pneumonia as well as nosocomial pneumonia, especially in patients with a humidifier. In this respect, the knowledge of their antibiotic susceptibilities could be of primary clinical importance. Especially, it is of particular interest to verify that current first-line recommendations for antibiotic therapy of pneumonia apply to this group of pathogens.

Bacterial and Amoebal Strains

P. acanthamoeba strain Bn9 was kindly provided by R. Amann (Lehrstuhl fur Mikrobiologie, Technische Universitat Munchen, Munich, Germany), whereas Hall's coccus was a gift from T. J. Robotham (Public Health Laboratory, Leeds, United Kingdom). Parachlamydia organisms were cultured in Acanthamoeba polyphaga, grown in 25-cm2 culture flasks (Becton Dickinson, Le Pont de Claix, France) containing PYG medium until almost complete lysis of amoebae (i.e., 4 days later). Cell supernatants were then recovered and centrifuged at 1,500 rpm (700 x g) for 10 min to remove cell debris. A Parachlamydia inoculum was prepared for each strain tested by diluting supernatants 1:100 in Page's amoebal saline, which corresponded to approximately 108 bacteria/ml. Titration of Parachlamydia was obtained by inoculating 10-fold serial dilutions of the primary inoculum to uninfected amoebal cultures and determining the highest dilution allowing lysis of amoebal monolayers after 4 days of incubation of cultures at 30°C.

Determination of MICs.

No antibiotic concentration tested displayed a toxic effect against amoebae. MICs for E. coli C.I.P. 53.126 and Staphylococcus aureus C.I.P. 103811 were compatible with those determined by the Pasteur Institute. P. acanthamoeba strains grew well in A. polyphaga cells, with complete lysis of amoebal monolayers in drug-free cultures after 4 days of incubation at 30°C. Among the ?-lactams tested, penicillin G, amoxicillin, ceftriaxone, and imipenem were ineffective at concentrations up to 32 mg/ml (Table ?(Table1).1). Both strains were susceptible to aminoglycosides, macrolides (including the newer ketolide, telithromycin), doxycycline, cotrimoxazole, and rifampin. In contrast, vancomycin, the activity of which is almost restricted to gram-positive bacteria, was ineffective. Thiamphenicol and, more importantly, the fluoroquinolone compounds ofloxacin and ciprofloxacin were not bacteriostatic at the concentrations tested.

MICs for Parachlamydia sp., including the Bn9 strain and Hall's coccus, as determined in an A. polyphaga culture model

We have evaluated in vitro susceptibilities of two strains belonging to the species P. acanthamoeba, with A. polyphaga as an in vitro cell system to support growth of these strictly intracellular bacteria. An amoebal system was used because of the impossibility of growing these bacteria in the other cell systems we currently use in our laboratory, including McCoy cells, Vero cells, P388D1 macrophage-like cells, or human embryonic lung fibroblast cells. Our model was based upon inhibition of amoebal lysis due to bacterial multiplication when antibiotics were added to the culture supernatant compared to that of drug-free controls. Thus, it was critical to verify that amoebal lysis was not related to antibiotic toxicity. Despite these technical limitations, our model allowed us for the first time to define the antibiotic susceptibility pattern of P. acanthamoeba and to compare it with those previously reported for C. trachomatis, Chlamydophila pneumoniae, and Chlamydophila psittaci, species that also belong to the order Chlamydiales.

P. acanthamoeba strains BN9 and Hall's coccus were found resistant to all beta-lactams tested. The in vitro activity of beta-lactams against C. trachomatis, C. pneumoniae, and C. psittaci has been demonstrated. Although these antibiotics are not considered first-line antibiotic therapy for Chlamydia-related pneumonia, amoxicillin has been used successfully in pregnant women with genital infection due to C. trachomatis. In contrast, we found aminoglycosides to be bacteriostatic against P. acanthamoeba strains, whereas C. trachomatis has been reported to be highly resistant to gentamicin. Cotrimoxazole could inhibit the growth of P. acanthamoeba and is also effective against C. trachomatis. In contrast, C. pneumoniae and C. psittaci are resistant to this antibiotic combination. More surprisingly, P. acanthamoeba strains were found to be resistant to fluoroquinolones, whereas C. trachomatis, C. pneumoniae, and C. psittaci are highly susceptible to these drugs. DNA gyrase is usually the primary target of fluoroquinolones in gram-negative bacteria, and resistance to fluoroquinolones due to mutation in gyrA (the gene encoding the alpha subunit of DNA gyrase) has been reported in C. trachomatis. The possibility of gyrA-mediated natural resistance to fluoroquinolones in P. acanthamoeba should be assessed.

results should be specifically examined considering the potential role of Parachlamydia spp. as etiological agents of human pneumonia. beta-Lactams are considered first-line antibiotic therapy of Streptococcus pneumoniae-related pneumonia, but are poorly effective against intracellular pathogens responsible for atypical pneumonia, such as Chlamydia spp., Legionella pneumophila, Mycoplasma pneumoniae, or Coxiella burnetii. This may also apply for P. acanthamoeba, a species resistant in vitro to these agents. In contrast, the susceptibility of P. acanthamoeba to macrolides and tetracycline suggests that the current practice of prescribing a macrolide or a tetracycline compound in patients with atypical pneumonia may well apply in case of Parachlamydia infection. The new ketolide compound telithromycin, which is active against erythromycin-resistant S. pneumoniae, as well as against the intracellular pathogens C. pneumoniae, L. pneumophila, M. pneumoniae, and C. burnetii, was found also active against the Parachlamydia strains. Fluoroquinolones, especially ofloxacin and ciprofloxacin, have been advocated as a possible alternative to macrolides in patients suffering atypical pneumonia, although their equivalence to erythromycin in case of legionellosis is still disputed. Interestingly, we found P. acanthamoeba to be highly resistant to these compounds in vitro.

Source - www.ncbi.nlm.nih.gov