H. Jared. Patten College.
Chronic inflammatory lesions like but is a manifestation of various conditions tuberculosis buy proscar 5mg with visa, syphilis and leprosy safe proscar 5 mg. Postoperative as after the operations on chitis 5 mg proscar with visa, epiglottitis buy proscar 5mg fast delivery, diphtheria, acute the larynx itself, pharynx, tongue and perichondritis or abscess of the larynx. Neoplastic: Neoplastic diseases of the larynx lar abscess, retropharyngeal abscess when associated with ulceration and and Ludwig’s angina may spread to infection are associated with oedema. Systemic diseases: Laryngeal oedema may be the manifestation of prolonged heart failure, renal failure and myxoedema. This may be due to sensitivity to some foods, drugs including antibiotics, insect bite, parenteral Fig. Oedema of the Larynx 341 Generalised urticaria with sudden respi- ratory difficulty may occur because of oedema of the larynx affecting the supraglottic and subglottic tissues. Therefore, if untreated, nasal obstruction The oedema may occur as a result of irritation, in the newborn period could and often does allergy or inflammation. There occurs prove fatal, whereas in adulthood, nasal distension of the submucosal tissues with obstruction may be regarded as a mere tissue fluid, lymph and inflammatory exudate. Swelling of the laryngeal tissues seen in Differentiation of upper from lower airway tuberculosis and myxoedema is called pseudo- obstruction is crucial. In tuberculosis the swelling is caused sternal, and intercostal retraction with by inflammatory infiltration with accumula- cyanosis are consistent with upper-airway tion of cells. Hyperreso- breather by virtue of the intranarial position nance suggests obstructive emphysema. Approximation of the Rarely is lower-airway obstruction by itself an epiglottis with the soft palate provides a immediate threat to life; upper-airway continuous, uninterrupted airway from the blockage represents a true emergency. This configuration, similar Obstruction at the laryngeal level in all mammals, is peculiarly lost in humans produced by congenital laryngeal deformities four to six months after birth. The structural and infection are common to childhood change provides the potential for oral development. Neoplastic obstruction of the respiration at an early age as the larynx laryngeal aperture and vocal cord paralysis descends in the neck with postnatal matura- are often diseases of adulthood. Treat- Choanal Atresia ment consists of tracheostomy and serial Choanal atresia, if bilateral, produces marked dilatations of the larynx. Acquired subglottic stenosis may be a result However, if the infant is made to cry, airway of direct trauma or high tracheostomy, obstruction is relieved and the colour but is most commonly found after a improves. Diagnosis is made by the passage period of prolonged intubation, either of nasal catheters. Emergency treatment during the neonatal period or following consists of establishing an oral airway follo- cardiac surgery. Stridor consisting of a low- the risk of subglottic mucosal damage pitched inspiratory flutter is produced by an and subglottic stenosis is increased. Stridor is often exaggerated in a tube, avoidance of infection and regular supine position and relieved in the prone. Diagnosis is made on direct laryngoscopy, Children with severe acquired subglottic which reveals an omega-shaped epiglottis. Laryngeal Webs Subglottic Stenosis Laryngeal webs arise due to arrest of laryn- It comprises the second largest group of new- geal development at about the tenth week of born laryngeal abnormalities. Approximately 75 per cent are results from: located at the glottic level, the remaining i. Because most cartilage, resulting in inspiratory and webs occur at the glottis, symptoms include expiratory stridor. The of the subglottis measures 6 to 8 mm in patient’s voice may be hoarse or he may be the normal newborn. Thin webs may respond to Oedema of the Larynx 343 serial laryngoscopic dilatation, whereas 2. Spasms of the larynx or choking may occur Urgent steps are taken to establish the due to number of lesions. Foreign materials in the larynx (solids and liquids) 62 Foreign Body in the Larynx and Tracheobronchial Tree Foreign body in the larynx and tracheobron- change in the voice. There may occur complete chial tree is one of the most important causes asphyxia which is further aggravated by the of stridor and dyspnoea in infancy and child- glottic oedema. Effects of the foreign body The changing position of the foreign body in vary according to its size, nature and location the trachea may give rise to signs like an in the larynx and tracheobronchial tree. Depend- Small and smooth metallic foreign bodies ing upon the obstruction one can hear an such as pins allow uninterrupted passage of asthamatic type of wheeze in such cases. Vegetable foreign bodies like peas Foreign bodies usually get arrested in the right and beans produce severe pneumonitis and main bronchus because it is wide and is more are also difficult to remove. The effects on the in line with the trachea than the left main patient and his respiratory system depend bronchus. If the foreign body gets in the bronchus is respiratory obstruction arrested in the larynx, it obstructs both the which could be partial or complete. In the trachea, if the foreign than the size of the bronchus, initially it allows body is large, there is an equal danger of total respiratory obstruction. It thus acts as a Foreign Body in the Larynx and Tracheobronchial Tree 345 check valve. This sort of action depends upon the expansion of the bronchus on inspiration and its contraction on expiration. Such foreign bodies will produce obstructive emphysema with overdistension of the affected lobe and respiratory embarrassment. Total obstruction If the blockage of the bron- chus is complete, either by the foreign body itself or by mucosal oedema, a stop valve type obstruction results. In patients with complete arrested at the bifurcation producing a com- bronchial obstruction there are signs of plete obstruction of one bronchus but only a collapse with shifting of the mediastinum to partial obstruction in the other. These Patients in whom the foreign bodies are reveal the nature and position of the foreign neglected may develop bronchiectasis, lung body (if radiopaque) as well as the effects abscess and empyema in the long run. Clinical Features Bronchoscopy may be done as diagnostic The clinical features of a case of foreign body investigation and as a therapeutic procedure in the larynx and tracheobronchial tree vary in cases where X-rays are not helpful but the from mild symptoms to asphyxia. The history may or may not be Foreign bodies in the larynx and the subglot- suggestive. The Such patients present with dyspnoea, foreign body is then removed by direct cough and wheezing. Foreign bodies in the trachea partial obstruction, then there are signs of and bronchi are removed by bronchoscopy. It hooks around the ligamentum rior laryngeal nerve is sensory to the larynx arteriosum and then ascends back into the but supplies motor fibres to the cricothyroid neck to supply the larynx. Laryngeal paralysis can be caused by a variety These nerves can get involved in a variety of lesions. The sites of paralysis can be supra- of lesions in the brain, at the base of the skull, nuclear or infranuclear. The right to a spastic type of paralysis and because recurrent laryngeal nerve leaves the vagus at larynx has bilateral representation in the the level of the subclavian artery and then cortex, only a widespread lesion of the cortex loops around it to ascend up in the tracheo- causes such paralysis (Figs 63. The Infranuclear paralysis is common and can left recurrent laryngeal nerve has a longer be due to following causes: Figs 63. Thyroid diseases, usually malignant nerve as a result of lesions at the base of skull b. Tumours and trauma to the oesopha- gus and trachea in the neck laryngeal nerve: This may occur in the neck e. Schimdt’s syndrome: There is involvement also has some vocal weakness because of of the accessory nerve (spinal and cranial paralysis of the cricothyroid muscle. Vernet’s syndrome: Involvement of the level difference of the cords as the affected vagus, accessory and glossopharyngeal cord lacks tension, because of cricothyroid nerves produces features of Schimdt’s paralysis. Hughlings-Jackson syndrome: Involvement nerve paralysis have been the subject of of the tenth, eleventh and twelfth cranial controversy. Collet-Sicard syndrome: (Villaret’s syndrome): of a gradually advancing organic lesion of the Involvement of the last four cranial nerves recurrent nerve, abductor fibres are more vulnerable to damage so the vocal cords and the cervical symphathetic trunk in the approximate near the midline, the adduction region of the jugular foramen produces is still possible and it is only in the late stages symptoms and signs of their paralysis. Klinkert syndrome: Involvement of the cords are paralysed in the intermediate recurrent laryngeal nerve and phrenic position (cadaveric position), and the reverse nerve, usually at the root of the neck or happens during recovery. Ortner’s syndrome: Paralysis of the recur- to explain the vulnerability of the abductors rent laryngeal nerve may occur as a result in laryngeal paralysis. However, neither of cardiomegaly particularly because of the separate grouping of the abductor and adduc- dilated left atrium in mitral stenosis. Because of laryngeal that median or paramedian position of the anaesthesia, there occur choking spells, paralysed vocal cord in recurrent laryngeal particularly on drinking fluids.
Treatment gap has been found to be higher in the rural areas and in the low income 128 countries discount 5mg proscar mastercard. The main problems faced by the health care professionals are lack of diagnostic facilities (51 generic proscar 5 mg visa. Affordable treatment is available : Phenytoin buy proscar 5mg fast delivery, Carbamazepine buy proscar 5 mg fast delivery, Phenobarbital and Valproic acid has been the choice of first line of treatment in most of the cases. The patient would not have personal or social stigma and the unnecessary cost of the 132 treatment would be curtailed. Phenobarbital has been the first choice of treatment in 96% of the developing countries, Phenytoin in 68. To promote public awareness about epilepsy: alleviation of myths and misconceptions, provision of treatment and prevention. To build capacity at all levels of human resource on prevention and management of epilepsy. Training: Health workers in the community can be effectively trained to identify cases and persuade them to seek treatment. The district medical officer will be considered as the core person to be trained in all aspects stated (public health aspects, prevention, differential diagnosis and diagnosis of epilepsy, particularly of generalized tonic clonic convulsions, febrile convulsions etc. Personnel involved in monitoring and data collection will also be trained in the use of various scales for monitoring change. Awareness generation: Intensive health awareness campaign will be carried out to promote public awareness about epilepsy, its prevention, benefits of treatment, myths and misconceptions etc. Communication needs assessment will be carried out to understand gaps in knowledge and attitude towards epilepsy and treatment practices. If required, second line of drugs can be prescribed at Medical Colleges and Tertiary Care hospitals. Role of the medical colleges will be in diagnosis, management and training for epilepsy. Continued follow-up of patients on treatment and referral system from primary level to secondary/tertiary level hospitals will be developed under the programme. Approximate cost of Firstline medicines for epilepsy and their costs are given below, which will be made available at all levels of care. Role of the medical colleges will be in diagnosis, management and training for epilepsy. Continued follow-up of patients on treatment and referral system from primary level to secondary/tertiary level hospitals will be developed under the programme. Second line medicines for treatment of epilepsy and their current prices are given below: Drug dosage Current price (Rs. Monitoring Indicators: National programme on epilepsy will be monitored and evaluated on the following indicators: 1. Number & % of patients diagnosed and those provided anti-epileptic drugs (by gender) 3. Early identification and diagnosis have implications for treatment, genetic counseling and estimation of the risk of recurrence, management of possible associated 134 conditions, prognostication and prevention, both at the individual and community level. In a Nationwide house to house survey of 3560 140 children 0–6 years of age at Delhi, disability was identified in 6. As reported by Sachdeva et al in a Cross sectional descriptive study conducted in field practice areas of Aligarh on 468 children aged 0–3 years, as many as 7. In community based study from Kerala on 12520 children upto 5 years, there were a total of 311 children with developmental delay, deviation, deformity or disability giving a prevalence 141 of 2. Speech and language problems were observed to be the most common disabilities (29. Hospital based study conducted on 200 apparently healthy children below 2 years of age attending immunization and well baby clinic in Bhopal reported prevalence of developmental 143 delay in 9. Retrospective analysis of case records of 100 consecutive children attending Early Intervention Clinic in Chandigarh reported 88% of the assessed children to be mentally retarded, 50% had cerebral palsy, 25% had epilepsy and 26% had other co-morbid physical 144 disorders. The existence of inborn genetic vulnerabilities in metabolic pathways may lower the threshold at which the influence of environmental factors may be felt, leading to an impact of environment that differs across the population based on genetic substrate. A number of environmental agents like heavy metals have been shown to demonstrate neurotoxic effects either in human or laboratory animal studies. Exposure to environmental agents with neurotoxic effects can result in a spectrum of adverse outcomes from severe mental retardation and disability to more subtle changes in function depending on the timing and dose of the chemical agent. There role is biologically plausible because they are known to disrupt enzyme functions, alter cellular signaling processes generate oxidative stress leading to apoptosis. Heavy metal poisoning is likely to be a major public health problem among Indian children especially those presenting with autistic spectrum disorders. The economic and other costs associated with neurobehavioral disabilities are tremendous. Therefore, there is an urgent need to identify potentially treatable and preventable environmental causes of at least some of these neurodevelopment disabilities. Justification for programme Research in Western countries has shown that children and their caregivers benefit from developmental monitoring during health visits in a number of ways: (1) If the child is developing typically, clinicians can provide reassurance, support parenting competence, and provide anticipatory guidance; (2) If the child is at developmental risk or has an established or emerging delay or difficulty, this can be detected early and addressed; and (3) In both situations, caregivers can be supported and informed about how to enhance their. Need for a uniform screening tool in the country:The prevalence of developmental delay reported by various authors in different studies varies over a wide range. This could be a result of a lack of uniformity in the instruments employed to assess developmental performance. It may be possible that pediatricians rarely use developmental or behavioral screening tests, preferring to rely more on developmental surveillance in the context of normal health care 137 provision. For screening at community level, there is a need for a standard uniform development screening tool. No National guidelines for incorporating developmental screening into existing health care: In high-income countries, an important strategy for the early detection and management of developmental difficulties has been the integration of developmental 140- monitoring of children (i. To date, however, methods designed specifically for developmental monitoring of 135-139, 146-148 young children by health care providers in developing countries are lacking. Focus on identification of the domain of developmental delay targeting at specific intervention not yet practiced in India: It’s vital to look at any dissociation between the domains of development (Speech and Language, Motor, Fine Motor, Personal and Social, Global). Identifying the patterns of developmental delays in children can aid in the diagnoses of neurodevelopment disorders and help anticipate the overall outcome of a child’s disability. However all the studies have been reported from an individual institution/state and no study is yet available in India which is a representative sample of the entire country. Hence, thisproject would be the first multicentric study with representation from all parts of the nation. Need for convergence at the community level, awareness raising and the involvement of local government: A large population in the South East region is rural based. For spreading awareness, networking with ongoing national programs (Integrated Child Development Scheme, Family planning, etc. Anganwari workers, multipurpose health 246 workers, Auxiliary Nurse Midwives and Non Government Organizations working in the community need to be educated. Emphasis on parent participation in both the detection of early symptoms and during intervention: Only 9% families were aware of the early signs of developmental delay, provision of disability certification and various welfare facilities provided by the central and state governments. Parents of the children with development delay are a rich resource in the community and are the child’s best and first teacher. Their concerns regarding delays/deviations in development have usually proved to be right. It is therefore logical and cost effective to involve them at every step of the planning and implementation process and treat them as co therapists. Human resource development for developmental screening and intervention in India In last 20 years, in India there has been a recognition that the quality and relevance of services for persons with disabilities is heavily dependent on a regular supply of well trained service providers and that investments in the development of human resources is the best strategy for the sustainability of rehabilitation services in the long run. This project also aims at training the grass root health workers along with the medical professionals at the secondary and tertiary levels of health care. The diagnosis for underlying etiology is very challenging as etiology is multifactorial. Early diagnosis and team management are necessary but the specialists involved in diagnosis and management like developmental pediatrician, child neurologist, child psychologist, geneticist, occupational therapist, physiotherapist, speech and language pathologist, radiologist, social welfare personnel and requisite resources are usually not available under one roof especially at peripheral level. There is, therefore a burning need to develop centres of expertise which can liaison with peripheral health care centers to provide easily available right intervention.
However proscar 5mg visa, if the sinus mucosa is so damaged that recovery is not possible generic 5mg proscar amex, then radical surgery is undertaken and the diseased mucosa removed order 5 mg proscar visa. Recently evidence in favour of anaerobic infection of the sinuses has been noted and metronidazole has proved helpful proscar 5 mg on line, particularly in association with antibiotics. Surgical procedures like antrum washout for maxillary sinusitis are helpful and may be repeated frequently to clear the sinus cavity of the discharge. Antrum puncture Under local anaesthesia, the is closed by oedema, then a second cannula trocar and cannula are put under the inferior can be inserted through the inferior meatus. The trocar is directed towards discharge and can be sent for cytological or the outer canthus of eye of the same side. At the end of the firm and steady pressure, the nasoantral wall procedure, local medication may be instilled is pierced and antral cavity entered. The trocar into the sinus cavity, the cannula is withdrawn is withdrawn and cannula placed properly in and nose cleaned. Difficulties and Dangers of The sinus is irrigated with sterile normal Antral Lavage Procedure saline at body temperature and the patient is told to breath through the mouth with the 1. The discharge comes out through turbinate and cause laceration of the the natural ostium of the sinus. Hence during a washout, a watch should be kept over the eyes and cheek to note any swelling or emphysema. Air should not be injected into the sinus as there is a danger of air embolism through Fig. The procedure should not be undertaken However, there may occur permanent during acute rhinitis or acute sinusitis as there is risk of spread of infection. Puncture of the maxillary sinus through This procedure has now fallen out of the middle meatus is avoided as it may favour because it has been demonstrated that damage the orbit and lead to reactionary the cilia of the maxillary antrum beat towards oedema of the natural ostium. The puncture can also be done through the More recently, this surgery has been canine fossa. It is a radical operation for those cases of permanent window near the floor of antrum chronic maxillary sinusitis where the so as to facilitate drainage of the discharge. Under local or general anaesthesia, the inferior meatus is exposed and then a harpoon or Myle’s gouge is passed through the nasoantral wall, under the inferior turbinate. This is a simple and less radical procedure with less risk of damage to blood vessels and nerves of the teeth. As an approach to sphenopalatine fossa for maxillary artery ligation and vidian neurectomy. There is no Steps of Operation need to remove all the diseased mucosa as was There are three main steps of the operation. A sublabial incision is made and the is always transported towards the natural anterolateral surface of the maxilla ostium and creating a dependent opening exposed (Figs 37. Through the canine fossa, an opening is not necessarily result in adequate drainage, made in the anterolateral wall of the as the secretions circumvent the antrostomy maxillary sinus and the sinus cavity opening and track towards natural ostium. A permanent opening is made in the nasoantral wall by performing an This procedure is a recent advance in sinus intranasal antrostomy. Rigid fibreoptic endoscopes: which provide It has now been clearly seen that if the better illumination with magnification to ostium of the diseased sinus is unblocked visualise whole area from different surgically by the removal of diseased ethmoi- angles (Fig. Microsurgical instruments: which facilitate of the sinus is re-established and the diseased accurate and to the point surgery desired Sinusitis 215 Fig. The anterior Firstly endoscope is passed between the ethmoidal cells being situated around the nasal septum and inferior turbinate examin- frontal recess and anterior to anterior ing thoroughly the whole area upto the ethmoidal artery, are removed by using 30° choana, visualising both eustachian tube endoscope and upward biting forceps. Secondly times it is necessary to open the agar nasi cells endoscope is passed along the middle meatus to have proper view of the area. After remov- to examine for any pathology and then ing anterior cells the opening of frontonasal between the middle turbinate and the septum duct is seen which is cleared by removing the upto anterior wall of sphenoid sinus and its diseased mucosa surrounding it. The posterior ethmoidal cells are In case of canine fossa puncture a sublabial reached by gently perforating the basal injection of 2 per cent xylocaine is also done. In this area posterior of middle turbinate downwards along the ethmoidal cells form a very close relationship. The sphenoid sinus anterior wall is perfo- curve of the uncinate process till just above rated and the ostium widened. The uncinate process is in sphenoid sinus should always be removed grasped firmly with Blakesley’s forceps and under direct vision especially towards lateral removed with a twisting movement, exposing wall which is having close relation to optic the infundibulum. Here the dissection must Common indications: stop on reaching the ethmoidal roof supe- i. Chronic sinusitis not responding to riorly, as there is anterior ethmoidal artery and medical treatment. Here only side of the forceps and not the tip, should be Uncommon indications: used to prevent accidental perforation, i. Surgery for Chronic Frontal Sinusitis Treatment of Ethmoiditis Drainage from the frontal sinus can be facili- tated by treating the associated obstructive The chronic inflammatory condition of the pathology in the nose like correcting the ethmoids may demand an operative proce- deflected septum or polypi. As the cells are small and multiple no vative procedures are not helpful, more drainage operation or lavage is possible. The radical procedures are undertaken, the disea- only feasible procedure is exenteration of the sed mucosa removed and sinus obliterated. Frontoethmoidectomy Ethmoidectomy The procedure is done to remove the disease The operation is indicated in chronic ethmoi- from the ethmoids and frontal sinus. Through ditis which usually manifests as polyposis, an external incision near the inner canthus, the particularly when simple polypectomy does bone is exposed and ethmoid labyrinth not help. The floor of the frontal sinus is The ethmoidectomy could be done removed and the diseased mucosa removed. The Thus the frontal sinus and ethmoids are ethmoids can also be exenterated through the converted into a cavity communicating with transantral route. The frontal sinus is exposed by raising a bony lid, hinged on the outer periosteum. Operations on the Sphenoid Sinus Sphenoidal sinus lavage can be done through its anterior wall by a trocar cannula. Complications of Sinusitis Osteomyelitis Infection from the sinus can lead to osteitis in compact bone and osteomyelitis in cancellous or diploic bone (Figs 37. Acute infection of the frontal sinus or ethmoid labyrinth may lead to osteomyelitis with resultant orbital cellulitis and proptosis. If infection is not controlled, spread to Pathology the meninges may take place with consequent Infection spreads either directly from mucous meningitis and brain abscess, or to sagittal and membrane to the diploe or through throm- cavernous sinuses with resulting septicaemia bophlebitis of veins of the sinus to the veins and cases end fatally. Osteomyelitis of maxilla of dura (dura being internal periosteum of is rarely a complication of maxillary sinusitis. Swelling and thrombosis takes place from the dural veins redness develop over the cheeks. Later there is discharge of pus the thin boneplates are destroyed and from the alveolus or into the nose or abscess Sinusitis 219 may point about the lower orbital margin. Temperature persistently elevated with Many cases of osteomyelitis skull result from slow pulse. Chlorides are decreased, sugar decreased or In 1-2 days another patch of oedema absent and protein is increased. Cerebral Abscess Intracranial Complications It may result from infection of any of para- Meningitis: Most common complication of nasal sinus but most common after chronic acute ethmoidal and sphenoidal sinusitis. Anterior pole of Symptoms homolateral frontal lobe is most common site of abscess, usually secondary to osteitis of 1. Neck rigidity less severe than in cases character, defects in memory and unilateral when meningitis follows lesions adjacent anosmia. Dura may be unduly tense and pulsations of brain absent then exploration of brain may be necessary. If abscess is found, it should be drained or excised if its capsule is firm sufficiently. Cavernous Sinus Thrombosis It is more with acute exacerbation of a chronic infection of posterior ethmoidal or sphenoidal sinuses. Proper treatment of sinus infection may allow a small fistula to heal up but a persis- tent large fistula requires surgery. The adjacent flaps can be rotated from the buccal mucosa or the palate and the fistula site closed. For large fistulae or those in which the above measures have failed, usual methods of closing are: (i) by a palatal flap, (ii) by a Fig. Clinically it presents of hard palate and must be large enough as a slowly growing painless cystic swelling to swing right across the fistulous causing downward and outward displace- opening to form the buccal flap as the ment of the orbital contents.
Cancer and burn patients also commonly suffer serious infections by this organism proscar 5mg discount, as do certain other individuals with immune system deficiencies discount 5 mg proscar otc. It has the ability to adapt to and thrive in many ecological niches purchase 5 mg proscar otc, from water and soil to plant and animal tissues proscar 5 mg without prescription. The bacterium is capable of utilizing a wide range of organic compounds as food sources, thus giving it an exceptional ability to colonize ecological niches where nutrients are limited. These proteins range from potent toxins that enter and kill host cells at or near the site of colonization to degradative enzymes that permanently disrupt the cell membranes and connective tissues in various organs. Analysis of its genome sequence has identified genes involved in locomotion, attachment, transport and utilization of nutrients, antibiotic efflux, and systems involved in sensing and responding to environmental changes. The typical Pseudomonas bacterium in nature might be found in a biofilm, attached to some surface or substrate, or in a planktonic form, as a unicellular organism, actively swimming by means of its flagellum. Pseudomonas is one of the most vigorous, fast- swimming bacteria seen in hay infusions and pond water samples. Waterborne Diseases ©6/1/2018 187 (866) 557-1746 In its natural habitat Pseudomonas aeruginosa is not particularly distinctive as a pseudomonad, but it does have a combination of physiological traits that are noteworthy and may relate to its pathogenesis. It is often observed "growing in distilled water" which is evidence of its minimal nutritional needs. In the laboratory, the simplest medium for growth of Pseudomonas aeruginosa consists of acetate for carbon and ammonium sulfate for nitrogen. Organic growth factors are not required, and it can use more than seventy-five organic compounds for growth. It is resistant to high concentrations of salts and dyes, weak antiseptics, and many commonly used antibiotics. These natural properties of the bacterium undoubtedly contribute to its ecological success as an opportunistic pathogen. They also help explain the ubiquitous nature of the organism and its prominance as a nosocomial pathogen. One type has a fried-egg appearance which is large and smooth, with flat edges and an elevated appearance. Another type, frequently obtained from respiratory and urinary tract secretions, has a mucoid appearance, which is attributed to the production of alginate slime. The smooth and mucoid colonies are presumed to play a role in colonization and virulence. Waterborne Diseases ©6/1/2018 188 (866) 557-1746 Pyoverdin and the blue pigment Pyocyanin P. The latter is produced abundantly in media of low-iron content and functions in iron metabolism in the bacterium. Pyocyanin (from "pyocyaneus") refers to "blue pus" which is a characteristic of suppurative infections caused by Pseudomonas aeruginosa. The soluble blue pigment pyocyanin is produced by many, but not all, strains of Pseudomonas aeruginosa. Pseudomonas aeruginosa is notorious for its resistance to antibiotics and is, therefore, a particularly dangerous and dreaded pathogen. Also, its tendency to colonize surfaces in a biofilm form makes the cells impervious to therapeutic concentrations antibiotics. Since its natural habitat is the soil, living in association with the bacilli, actinomycetes and molds, it has developed resistance to a variety of their naturally-occurring antibiotics. Only a few antibiotics are effective against Pseudomonas, including fluoroquinolones, gentamicin and imipenem, and even these antibiotics are not effective against all strains. The futility of treating Pseudomonas infections with antibiotics is most dramatically illustrated in cystic fibrosis patients, virtually all of whom eventually become infected with a strain that is so resistant that it cannot be treated. It grows well on most laboratory media and commonly is isolated on blood agar or eosin-methylthionine blue agar. It is identified on the basis of its Gram morphology, inability to ferment lactose, a positive oxidase reaction, its fruity odor, and its ability to grow at 42° C. Waterborne Diseases ©6/1/2018 189 (866) 557-1746 Pathogenesis For an opportunistic pathogen such as Pseudomonas aeruginosa, the disease process begins with some alteration or circumvention of normal host defenses. The pathogenesis of Pseudomonas infections is multifactorial, as suggested by the number and wide array of virulence determinants possessed by the bacterium. Multiple and diverse determinants of virulence are expected in the wide range of diseases caused, which include septicemia, urinary tract infections, pneumonia, chronic lung infections, endocarditis, dermatitis, and osteochondritis. The ultimate Pseudomonas infection may be seen as composed of three distinct stages: (1) bacterial attachment and colonization; (2) local invasion; (3) disseminated systemic disease. Particular bacterial determinants of virulence mediate each of these stages and are ultimately responsible for the characteristic syndromes that accompany the disease. Colonization Although colonization usually precedes infections by Pseudomonas aeruginosa, the exact source and mode of transmission of the pathogen are often unclear because of its ubiquitous presence in the environment. It is sometimes present as part of the normal flora of humans, although the prevalence of colonization of healthy individuals outside the hospital is relatively low (estimates range from 0 to 24 percent depending on the anatomical locale). The fimbriae of Pseudomonas will adhere to the epithelial cells of the upper respiratory tract and, by inference, to other epithelial cells as well. These adhesions appear to bind to specific galactose, mannose or sialic acid receptors on epithelial cells. Colonization of the respiratory tract by Pseudomonas requires fimbrial adherence and may be aided by production of a protease enzyme that degrades fibronectin in order to expose the underlying fimbrial receptors on the epithelial cell surface. Tissue injury may also play a role in colonization of the respiratory tract since P. This has been called opportunistic adherence, and it may be an important step in Pseudomonas keratitis and urinary tract infections, as well as infections of the respiratory tract. The receptor on tracheal epithelial cells for Pseudomonas pili is probably sialic acid (N-acetylneuraminic acid). Mucoid strains, which produce an exopolysaccharide (alginate) have an additional or alternative adhesion which attaches to the tracheobronchial mucin (N-acetylglucosamine). Besides pili and the mucoid polysaccharide, there are possibly two other cell surface adhesions utilized by Pseudomonas to colonize the respiratory epithelium or mucin. Also, it is likely that surface-bound exoenzyme S could serve as an adhesion for glycolipids on respiratory cells. Alginate slime forms the matrix of the Pseudomonas biofilm which anchors the cells to their environment and, in medical situations, it protects the bacteria from the host defenses such as lymphocytes, phagocytes, the ciliary action of the respiratory tract, antibodies and complement. Waterborne Diseases ©6/1/2018 190 (866) 557-1746 Shigellosis Shigella Section Shigella dysenteriae type 1(or bacillary dysentery) is the only cause of epidemic dysentery. This organism is generally found in the stool of infected individuals, as well as in contaminated water supplies. It is known to be able to survive on soiled linens for up to seven weeks, in water supplies for 5-11 days, and in kitchen waste for 1-4 days. The infections caused by this organism are generally seen in developing countries and areas of poor sanitation. Transmission occurs via direct or indirect contact with individuals who are infected by ingesting contaminated water, or food, as well as contact with fecal material. The Shigella germ is actually a family of bacteria that can cause diarrhea in humans. Shigella were discovered over 100 years ago by a Japanese scientist named Shiga, for whom they are named. There are several different kinds of Shigella bacteria: Shigella sonnei, also known as "Group D" Shigella, accounts for over two-thirds of the shigellosis in the United States. Waterborne Diseases ©6/1/2018 191 (866) 557-1746 A second type, Shigella flexneri, or "group B" Shigella, accounts for almost all of the rest. Other types of Shigella are rare in this country, though they continue to be important causes of disease in the developing world. One type found in the developing world, Shigella dysenteriae type 1, causes deadly epidemics there. Microbial Characteristics Shigella dysenteriae is a Gram (-), non-spore forming bacillus that survives as a facultative anaerobe. When testing for it in the laboratory, you can help identify it by the fact that it is non-motile, and lactose and lysine (-). This organism, unlike some enterics, does not produce gas when breaking down carbohydrates. This disease is most often associated with areas of overcrowding and poor sanitation (developing countries). Symptoms of dysentery due to this organism include mild to severe diarrhea, which is sometimes bloody or watery.