INTRODUCTION:

         The bacteria in the genus Vibrio are gram-negative, stiff, curved rods and comma-shaped, asporogenous, and non-capsulated. Vibrios can be found in marine ecosystems and surface waters all over the world. Vibrio cholera is the most important member of the genus.

MEDICALLY IMPORTANT SPECIES:

          Three species off vibrio are medically important:

1.    Vibrio cholera
2.    Vibrio parahaemolyticus
3.   Vibrio vulnificus

VIRIO CHOLERA:

        Vibrio cholerae are gram-negative rods that are stiff, curved, and actively motile. Their development can be aided by the use of NaCl. They thrive at pH 6.4–9.6 (optimum 8.2) and temperatures ranging from 16 to 400 degrees Celsius (Optimum 370C).

        Cholera is caused by the bacteria Vibrio cholerae, which has been around for a long time. Symptoms can be minor, moderate, or severe. Large quantities of watery diarrhoea that lasts a few days is the most common symptom. Vomiting and muscular cramps are other possible side effects.

          Cholera, according to the World Health Organization, is a highly contagious disease that causes severe acute watery diarrhoea. After swallowing infected food or water, symptoms can appear anywhere from 12 hours to 5 days later. Cholera affects both children and adults, and if left untreated, illness can kill within hours. Although the bacteria are present in their faeces, most people infected with V. cholera exhibit no symptoms.

           A medical practitioner can treat it, but it requires a lab test or imaging. The severity of the diarrhoea determines the treatment. Antibiotics and self-care methods can usually be used to treat most cases.

VIBRIO PARAHAEMOLYTICUS:

         Vibrio parahaemolyticus is a Gram-negative motile bacterium found worldwide in marine habitats. It is a significant food-borne pathogen that causes life-threatening infections in humans when raw or undercooked seafood is consumed.

           Symptoms of Vibrio parahaemolyticus infection usually occur within 24 hours after ingesting the bacteria. Symptoms may include:

·         Watery diarrhea

·         Abdominal cramps

·         Nausea

·         Vomiting

·         Fever

·         Headache

·         Bloody diarrhea

          Antibiotic treatment is normally not required for V. parahaemolyticus gastro, however antibiotic therapy may be required in situations of protracted diarrhoea. The following are some general guidelines for treating gastro:

• Make sure you drink plenty of water. For children and adults with mild to moderate dehydration, an oral rehydration solution is strongly suggested.
• Unless expressly directed by a doctor, do not administer drugs to prevent vomiting or diarrhoea (particularly in youngsters).
• Give hungry youngsters their typical foods, but steer clear of sugary or fatty items.

VIBRIO VULNIFICUS:

          Vibrio vulnificus is a pathogenic bacteria of the genus Vibrio that is gram-negative, motile, and curved rod-shaped (bacillus). It can be found in aquatic habitats. In the summer, when the water warms, Vibrio vulnificus is found in increasing numbers. When a person consumes raw or uncooked shellfish, bacteria enters the digestive tract and quickly multiplies. In immunocompetent people, it can infect wounds and cause local wound infections.

The following are the most prevalent vibrio vulnificus symptoms:

• Cellulitis is a skin infection that affects the dermal and subcutaneous layers.
• Chills and weakness are symptoms of a fever.
• Sepsis.
• Breathing problems or irregular heartbeats.
• Reduced urination is one of the signs of organ failure.
• Platelet count has dropped.
• Pain in the abdomen, nausea, and diarrhoea.
• Lymphangia (swelling of the lymph nodes).

PREVENTION AND CONTROL:

         To prevent Vibrio illness, don’t eat raw oysters or other shellfish, and stay out of brackish or salt water if you have a wound. 

    Haemophilus is a gram-negative rod that is tiny and non-motile. Inhaled droplets or direct touch with contaminated secretions can spread the disease. The flora of the human respiratory system and mouth cavity in its natural state. They are gram-negative aerobic bacteria with a polysaccharide capsule. Polysaccharide capsules come in six different serotypes (a-f). Type b bacteria are responsible for 95% of invasive illnesses (Hib).

     They are non-motile, non-sporing, gramme negative rod or coccobacillus, and Pleomorphic in size (1-2 X 0.3 – 0.5 microns) (old culture). Infected sputum has clusters of Coccobacillary forms, while infected CSF has long bacillary and filamentous forms (Meningitis).

     Carbol fuchsin (5-15 minutes) or Loeffler's methylene blue can be used to stain them. They have a lot of strain that has been capsulated. India ink wet films and Quelling reaction discolour the capsule. CSF, blood, a throat swab, sputum, and pus aspirates from the joints of the Middle Ear Sinuses can all be used to obtain samples. On Blood agar and Chocolate agar, it can be cultivated. Carbon dioxide levels of 5–10% are required. At 370 degrees Celsius, a stripe of Staphylococcus should be streaked across the plate.

    As Satellitisim, opaque colonies appear. On Leviathan media, Iridescence is demonstrated. After 24 hours on Chocolate agar, flat, grayish-brown colonies with a diameter of 1-2 mm appeared. Staphylococci colonies on sheep The release of NAD by blood agar results in the satellite growth phenomena.

WHAT IS SATELLITE GROWTH?

      When Staph aureus is  streaked across plate  of Blood agar with a  species containing H  Influenza the colonies  which are large  develop along the  streak of  Staphylococcus and  small further away giving a satellite like pattern.

WHAT IS HEAMOPHILUS INFECTION?

       Hib is a bacterial infection that in young children can cause a potentially fatal brain infection. Hib can cause meningitis (inflammation of the brain and spinal column's coverings), bloodstream infections, pneumonia, arthritis, and infections in other regions of the body. Haemophilus influenzae is a bacteria that can be found in both children and adults' noses and throats. Some people carry the bacteria but do not become ill as a result of it.

CAUSES:

       Through respiratory droplets, people transfer H. influenzae, including Hib, to others. When someone with the germs in their nose or throat coughs or sneezes, this happens. Even if they aren't sick, people with the bacteria in their noses and throats can spread it.

IS IT SAME AS FLU?

       Hib does not cause influenza, despite its name (the flu). The flu is caused by a virus, not bacteria.

 TREATMENT:

      The pillars of treatment for Haemophilus influenza infections are antibiotics and supportive care. Until antibiotic sensitivities are known, invasive and severe H influenzae type b (Hib) infections are best treated with an intravenous third-generation cephalosporin.

       The first dose of Hib vaccine is normally given to infants at the age of two months, and the series is usually completed at the age of 12–15 months. Children aged 12 months to 5 years who have not been fully vaccinated against Hib may require one or more doses of the vaccine.

IS HAEMOPHILUS STD?

       Chancroid is a sexually transmitted disease (STD) caused by Haemophilus ducreyi infection. It is characterised by painful necrotizing vaginal ulcers that may be accompanied by lymphadenopathy in the inguinal region. It's a condition that's very contagious but treatable.

     In the 4th century B.C., Hippocrates provided the first clinical description of diphtheria. Bretonneu (1821), a French army surgeon, described the disease's unique clinical characteristics and coined the term "dipht'erie" to refer to the tough leathery pseudo membrane that occurs in the oropharynx and occasionally in the nasopharynx.

    Corynebacteria, often known as "Coryneform bacteria," are a type of positive bacillus that does not produce spores. They're usually clubbed or unevenly formed; coryne means "club" in Greek. Diphtheria's causal agent, Corynebacterium diphtheria, is the most common pathogen in this group. C. Ulcerans, a pathogenic corynebacterium that causes diphtheria-like sores, is another pathogenic corynebacterium. C. minutissimum and C. tenuis are Corynebacteria that cause superficial skin diseases. Normal commensals in the throat, skin, and conjunctiva are caused by diphtheria.

    Slender Gram-positive rods, pleomorphic, and readily decolonized Corynebacterium diphtheria. They are not capsule-forming, sporing, or motile. Polymetaphosphate granules can be detected in the cells. When stained with Loeffler's Methylene Blue, they take on a bluish purple appearance against faintly stained cytoplasm, earning the name 'Metachromatic granules.' 'Volatin granules' or 'Babes Ernst granules' are other names for these granules. They are frequently found at the poles, referred to as 'polar bodies.'

      Special stains for demonstrating the granules are Albert’s stain, Neisser’s stain, Ponder’s stain.

The bacilli are arranged in pairs, palisades or small groups; the bacilli lie at various angles to each other, resembling the letters, V or L. This is called, “Chinese letter pattern” or “cuneiform pattern.

     They are both facultative anaerobes and aerobes. The ideal temperature is 370 degrees Celsius. On conventional media, growth is scarce. For proper growth, blood, serum, or eggs are required. Potassium tellurite (0.04%) is a'selective agent,' inhibiting the growth of most oral commensals while slowing the growth of Candida albicans and Staphylococcus aureus.

       Cultures remain viable for 2-3 wks at 25-300C. Can be destroyed by heat. Resistant to light, desiccation or freezing. Easily destroyed by antiseptics. Susceptible to Penicillin, erythromycin and broad spectrum antibiotics.

            Leptospira are commonly known as spirochete. They are actively motile. They possess both gram-negative and gram-positive characteristics. Due to poor staining, can only visible on dark field microscope. They are beta-hemolytic in nature.

           Leptospira organisms are very thin, tightly coiled; obligate aerobic spirochetes characterized by a unique flexuous type of motility. The genus is divided into two species:

ü                 *The pathogenic leptospires L interrogans

ü                 *Free-living leptospire  L biflexa(non-pathogenic)

Wild and domestic animals are the illness's primary hosts, and the disease is a major cause of economic loss in the meat and dairy industries. L biflexa serotypes exist as free-living organisms in water and soil, and humans are unwitting carriers for this disseminated disease, which ranges in severity from asymptomatic to lethal.

LEPTOSPIROSIS:

    LEPTOSPIROSIS is the name for a leptospira infection. Rodents are the major reservoir because, once infected, they shed the germs for the rest of their lives. Humans become infected by ingesting Leptospira-contaminated water. Leptospires can also enter the body through abrasions on the skin. There is a 6- to 8-day incubation period. Leptospires enters the bloodstream and multiplies for one week. Then it leaves the bloodstream and enters the liver, kidney, spleen, and meninges. In the later phases, it is eliminated primarily in the urine.

WEIL’S DISEASE:

It is the severe form of leptospirosis. It can cause fever, conjunctivitis, albuminurea, jaundice and hemorrhage. It’s implicated group is L.icterrohaemorrhagiae.

LIFE CYCLE:

CAUSES:

Many animals carry the organism, which resides in their kidneys. Through their urine, it ends up in the soil and water. The germ can enter your body through holes in your skin, such as scrapes, open wounds, or dry patches, if you're near soil or water where an infected animal has peed. It can also get into your body through your mouth, nose, or genitals. It's difficult to contract it from another person, yet it can be transmitted through sex or nursing.

If you spend a lot of time amid animals or in the outdoors, you're at concern.            

SYMPTOMS:

Leptospirosis can cause a variety of symptoms in humans, including 

• High fever.
• Headache.
• Chills.
• Muscle pain.
• Vomiting.
• Jaundice is a type of jaundice that occurs (yellow skin and eyes)
• Eyes that are bright red.
• Pain in the abdomen.

LABORATORY DIAGNOSIS:

Specimen should be taken from blood in case of initial stage but in case of later stage specimens are taken from urine. Serological tests like screening test & serotype specific test are useful method of diagnosis.

TREATMENT:

Penicillin, Tetracycline and Erythromycin are useful drugs in this case. There is no vaccine available till now. Natural immunity develops after infection with corresponding serotype.