Development of Bacterial Therapeutics against the Bovine Respiratory Pathogen Mannheimia haemolytica

Bovine respiratory disease (BRD) is a major cause of morbidity and mortality in beef cattle. Recent evidence suggests that commensal bacteria of the bovine nasopharynx have an important role in maintaining respiratory health by providing colonization resistance against pathogens. The objective of this study was to screen and select bacterial therapeutic candidates from the nasopharynxes of feedlot cattle to mitigate the BRD pathogen Mannheimia haemolytica In a stepwise approach, bacteria (n = 300) isolated from the nasopharynxes of 100 healthy feedlot cattle were identified and initially screened (n = 178 isolates from 12 different genera) for growth inhibition of M. haemolytica Subsequently, selected isolates were evaluated for the ability to adhere to bovine turbinate (BT) cells (n = 47), compete against M. haemolytica for BT cell adherence (n = 15), and modulate gene expression in BT cells (n = 10). Lactobacillus strains had the strongest inhibition of M. haemolytica, with 88% of the isolates (n =33) having inhibition zones ranging from 17 to 23 mm. Adherence to BT cells ranged from 3.4 to 8.0 log10 CFU per 105 BT cells. All the isolates tested in competition assays reduced M. haemolytica adherence to BT cells (32% to 78%). Among 84 bovine genes evaluated, selected isolates upregulated expression of interleukin 8 (IL-8) and IL-6 (P < 0.05). After ranking isolates for greatest inhibition, adhesion, competition, and immunomodulation properties, 6 Lactobacillus strains from 4 different species were selected as the best candidates for further development as intranasal bacterial therapeutics to mitigate M. haemolytica infection in feedlot cattle.IMPORTANCE Bovine respiratory disease (BRD) is a significant animal health issue impacting the beef industry. Current BRD prevention strategies rely mainly on metaphylactic use of antimicrobials when cattle enter feedlots. However, a recent increase in BRD-associated bacterial pathogens that are resistant to metaphylactic antimicrobials highlights a pressing need for the development of novel mitigation strategies. Based upon previous research showing the importance of respiratory commensal bacteria in protecting against bronchopneumonia, this study aimed to develop bacterial therapeutics that could be used to mitigate the BRD pathogen Mannheimia haemolytica Bacteria isolated from the respiratory tracts of healthy cattle were characterized for their inhibitory, adhesive, and immunomodulatory properties. In total, 6 strains were identified as having the best properties for use as intranasal therapeutics to inhibit M. haemolytica If successful in vivo, these strains offer an alternative to metaphylactic antimicrobial use in feedlot cattle for mitigating BRD.

[Treatment of congenital heart disease complicated by severe bronchopneumonia in infants]

OBJECTIVE

To study the treatment and the treatment outcome in infants with congenital heart disease complicated by severe pneumonia and heart failure.

METHODS

The clinical data of 24 infants with congenital heart disease (left to right shunt) complicated by severe pneumonia and heart failure between January 2007 and December 2007 were retrospectively reviewed.

RESULTS

Twenty-two infants recovered and 2 died. Severe pneumonia and heart failure were refractory even after 1-2 months medical treatment in 6 infants at ages of <6 months. They then underwent an open heart surgery under the mechanical ventilation and tracheal intubations and were successfully cured. The other 18 infants underwent a selective heart surgery after pneumonia and heart failure had been improved. Sixteen infants were successfully cured and 2 died of postoperative low cardiac output syndrome and diffuse intravascular clotting.

CONCLUSIONS

The heart surgery should be performed early when the medical treatment does not work in infants with congenital heart disease complicated by severe pneumonia and heart failure. This may improve their outcome.

[A young infant with afebrile pneumonia caused by Chlamydia trachomatis]

Pregnant women who have an urogenital Chlamydia trachomatis infection may transmit the infection to their infants. Conjunctivitis and nasopharyngeal infection are the most frequent manifestations. Less frequently the infants may develop pneumonia. We report a case of a 5-week-old girl with poor feeding, staccato cough and clinical signs of pneumonia. Chest radiography revealed severe bronchopneumonia. Despite of intravenous therapy with ampicillin and gentamicin respiration deteriorated and oxygen supplementation became necessary. After additional treatment with oral erythromycin (50 mg/kg per day) had been started the clinical condition improved. Polymerase chain reaction with a nasopharyngeal specimen was found to be positive for Chlamydia trachomatis.

[Diagnostics and treatment of ventilator-associated bronchopneumonia at a coronary unit]

Ventilator-associated pneumonia represents a severe complication in patients who are receiving mechanical ventilation. The incidence is presumed to be 25% of the total number of mechanically ventilated patients. The clinical assessment is usually based on the presence of a new radiographic infiltrate, fever, blood leukocytosis, or leukopenia and purulent tracheal secretions. According to the time after tracheal intubation when VAP occurs we can distinguish early and late onset VAP, which differs in terms of infectious agent. The early and adequate antibiotic therapy together with the basic preventive treatment represents the only possibility to avoid the complications. The article reviews the actual knowledge of this phenomenon, the adequate diagnostic attitudes and therapeutic possibilities.

[Instrumental treatment of chronic obstructive bronchopneumonia. The place of non-invasive ventilation]

OF DEBATABLE INTEREST: Although the place of non-invasive ventilation (NIV) is indisputable in the management of acute respiratory failure during chronic obstructive pulmonary disease (COPD), where it significantly reduces the rate of intubation and complications and the number of days spent in intensive care, its interest is debated in the long term management of chronic obstructive respiratory failure (CORF). EFFICACY TO BE DEMONSTRATED: Although several short term studies confirm the efficacy of NIV on some physiological parameters and on the quality of sleep and quality of life in some patients, long term prospective studies are still too few and do not confirm these data on small series of patients and limited time. FOR CERTAIN CATEGORIES OF PATIENTS: It is legitimous to consider that sub-groups of patients respond to NIV, notably in cases of instable CORF non-controlled by medical treatments or by well-conducted kinesitherapy and oxygentherapy.

[Prevention and treatment of infectious complications after pulmonary resection--part I]

Pulmonary complications are still the most frequent cause of morbidity and mortality after lung resections. One of the most significant ones are infectious complications, particularly pneumonia. Pneumonia is very often caused by residual atelectasis. We evaluated a group of 75 patients after lung resection focused on occurrence of these two significant complications. We emphasize the prevention of these complications and draw attention to the bronchoscopy and "breathing reeducation" (physical therapy).

Two cases of severe bronchopneumonia due to influenza A (H3N2) virus: detection of influenza virus gene using reverse transcription polymerase chain reaction

We report two cases of severe bronchopneumonia due to influenza A (H3N2) virus. The severity of the disease necessitated initiation of empiric therapy based on the present illness and clinical data on admission. Both patients were improved by artificial ventilation with positive end-expiratory pressures and administration of broad spectrum antibiotics and corticosteroids before confirming the diagnosis of viral bronchopneumonia using viral culture and serological tests. Within 24 hours, influenza A (H3N2) virus was identified by amplification of the pathogen genes by reverse transcription polymerase chain reaction (RT-PCR) using the stored bronchoalveolar lavage (BAL) fluids of both cases. This suggests that a combination of detection methods of pathogens using RT-PCR and BAL fluid will facilitate determination of rational treatment aimed at influenza A virus.

Prevention and treatment of bronchopneumonia in mice caused by mouse-adapted variant of avian H5N2 influenza A virus using monoclonal antibody against conserved epitope in the HA stem region

The effects of monoclonal antibody (MAb) C179 recognizing a conformational epitope in the middle of the hemagglutinine (HA) stem region were examined in a mouse model in the experiments of prevention and treatment of lethal bronchopneumonia caused by influenza A virus of H5 subtype. To model the lethal infection, avian nonpathogenic strain A/mallard duck/Pennsylvania/10218/84 (H5N2) was adapted to mice. This resulted in highly pathogenic pneumovirulent mouse-adapted (MA) variant, which was characterized. Three amino acid changes were found in the HA1 subunit of HA of MA virus. One of these was located inside the region of the conformational epitope recognized by MAb C179. However, this substitution was not significant for the recognition of HA and virus neutralization by MAb C179 in vitro and in vivo. Intraperitoneal administration of two different concentrations of MAb C179 one day before or two days after the virus challenge significantly decreased mortality rate. These results suggest that MAb C179 is efficient not only in the prevention and treatment of H1 and H2 influenza virus bronchopneumonia, as was reported previously, but also of H5-induced bronchopneumonia as well, and demonstrate in vivo the existence of a common neutralizing epitope in the HAs of these three subtypes.

Concurrent Aelurostrongylus abstrusus infection and salmonellosis in a kitten

A 14-week-old kitten had a history of vomiting, diarrhoea and pyrexia, all of which resolved without treatment. Three weeks later the kitten developed a violent non-productive dry cough. Thoracic radiographs revealed pneumothorax and nodular alveolar disease. Aelurostrongylus abstrusus larvae and intracellular Gram-negative bacilli were seen in bronchial wash fluid and pleural exudate, and Salmonella Typhimurium was cultured from both fluids but not from faeces. Therapy included unilateral closed-tube thoracostomy, enrofloxacin and fenbendazole. Historical signs were compatible with gastrointestinal salmonellosis and secondary broncho-pneumonia. Seeding of the lungs with salmonellae may have occurred as a result of migration of A abstrusus from a gastro-intestinal tract residually infected or colonised by S Typhimurium. Alternatively, the development of lungworm infection in the cat may have activated quiescent S Typhimurium pulmonary granulomata from bacteraemia secondary to gastro-intestinal salmonellosis. Two years after diagnosis the cat was reportedly in good health.

Alterations in peripheral blood leukocytes functions during enzootic bronchopneumonia of calves. Effect of treatment with antibiotics and immunomodulators

Twelve calves from over veal calf farm were divided into two groups: group I-6 calves which developed typical signs of enzootic bronchopneumonia and group II-6 calves with no symptoms of the disease. Both groups of calves were compared with respect to changes in several hematological parameters. Some functions of peripheral blood leukocytes as random migration, phagocytic index, percent of phagocytic cells and percent of NBT positive cells were also scored. In addition, changes in serum levels of interferon (IFN) and tumor necrosis factor (TNF) and the ability of peripheral blood leukocytes (PBL) to produce IFN and TNF were quantitated by biological methods. On the day of diagnosis, in group I of calves a significant increase in the total serum protein concentration, hemoglobin content, red and white blood cells counts in comparison to control calves (group II) was observed. The increased number of NBT positive neutrophils and moderate levels of serum IFN and TNF correlated with elevated body temperature, breathing and heart rates. Calves with bronchopneumonia (group I) after diagnosis of the disease were treated with Tylbian (tylosine derivative), Flumetazon (glucocorticoid), Emulselvet (immunomodulator), bromhexinum and sulphonamides. Seven days after the beginning of treatment with medicaments a significant improvement in clinical symptoms was observed, however, the ability of PBL to cytokine production increased significantly 2 weeks after beginning of treatment and correlated with significant increase in random migration of neutrophils and their phagocytic activity, measured by the percent of phagocytic cells. Unexpectedly, in control calves (group II), not exhibiting any symptoms of bronchopneumonia at the beginning of experiment, high serum IFN titers were detected which decreased significantly during the first week of observation. In contrast to that the ability of PBL of control calves to produce IFN increased significantly within 3 weeks of observation. The correlations between the ability of PBL to produce cytokine and the development of clinical symptoms of bronchopneumonia are discussed.

Prevention and treatment of lethal influenza A virus bronchopneumonia in mice by monoclonal antibody against haemagglutinin stem region

The protective properties of monoclonal antibody (MoAb) C179 directed to the stem region of haemagglutinin (HA) H2 that possessed fusion-inhibition and unique broad cross-neutralizing activities were examined in a mouse model. The MoAb efficiently protected mice against a lethal challenge with pneumovirulent human (H1) and avian (H2) strains of influenza A virus. Survival rates in mice that received intraperitonealy (i.p.) 1000 micrograms of the MoAb per mouse a day before the virus challenge were 90% for H1 and 100% for H2 strain. The dose of the MoAb of 100 micrograms per mouse significantly decreased mortality in mice. Moreover, the MoAb was also efficient in treatment of lethal bronhopneumonia caused by H2 influenza virus. The survival rate in mice that received 1000 micrograms of the MoAb per mouse 2 days after the virus challenge was 90%, while that in the control group was 30% only. These results indicate that the MoAb was effective in protection of animals against lethal influenza A infection without significant difference between H1 and H2 subtypes. The MoAb exerted significant effect in treatment of mice infected with H2 influenza virus. Thus, these data allow to suggest that the stem region of HA might be a potential target for prevention of influenza virus infection and antiviral therapy.

Airway and respiratory management following non-lethal hanging

PURPOSE

To review the literature on airway and respiratory management following non-lethal (suicidal) hanging and to describe the anatomy, injury and pathophysiological sequelae and their impact on patient care.

SOURCE

A Medline literature search of English-language and English-abstracted papers for 1990-96. Keywords were hanging; strangulation; airway obstruction; pulmonary oedema. Filters were applied to limit the search to relevant citations. (i.e., keywords = pulmonary oedema; filters = postobstructive, neurogenic). Citations were then hand-culled to obtain current and relevant papers about an unusual cohort of patients. A hand search of the bibliographies of relevant papers supplemented the Medline search. A review of our experience at the University of Ottawa adult hospitals over the last decade was also undertaken to determine the relevance of the literature to our clinical experiences.

PRINCIPAL FINDINGS

Most victims are young men and survivors are uncommon. Laryngo-tracheal injuries, although reported in 20-50% of postmortem examinations, are infrequent in survivors and have little impact on airway management. Spinal injuries are rare in survivors but should be excluded. Pulmonary complications including pulmonary oedema and bronchopneumonia are implicated in most in-hospital deaths. Pulmonary oedema is likely due to neurogenic factors or negative intrathoracic pressure. Although neurological injury determines outcome following hanging, initial neurological presentation is of limited prognostic value: a poor initial condition does not exclude a good recovery.

CONCLUSION

Airway injuries severe enough to interfere with airway management are uncommon after attempted suicide by hanging. Irrespective of the initial neurological assessment, aggressive and early resuscitation to optimize cerebral oxygenation is recommended.

[Aspiration bronchopneumonia as a complication of acute poisoning with psychotropic drugs]

In the five year period, retrospectively and prospectively, the frequency, clinical, radiographic and bacteriological characteristics of the aspiration bronchopneumonia (ABPN) were followed in the acute poisoning by psychotropic drugs (PD). In 1769 patients with acute poisoning by PD, ABPN was determined in 44 (2.49%) patients, and most frequently in groups with polymedicamentous (5.99%) and neuroleptic (5.17%) poisoning, and rarely in the group poisoned by anxiolytics (0.77%). Severest poisonings by PD were complicated by ABPN in 16.84% of cases. High conformity of clinical and radiographic finding of bronchopneumonia was achieved. The diagnosis of bronchopneumonia was established on the day of admission at the Clinic in 81.9% of cases on the other day in 13.6% and on the third day in 4.5% of patients. Bacteriological examination of sputum revealed the pathogens in 63.6% of patients, but in no patients the anaerobic bacteria were isolated. The treatment was very complex, and beside the detoxification measures, it was necessary to remove the aspirated contents from the respiratory tract (usually during endotracheal intubation or therapeutic bronchoscopy) and immediately apply antibiotics. The examinees were hospitalized twice longer than the patients whose course of poisoning by PD was not complicated by ABPN. The poisoning ended lethally in two (4.5%) patients. In no cases the ABPN was the immediate cause of death, but it significantly contributed to the lethal outcome.

[Tetraparesis in an infant after prolonged administration of pancuronium]

Long-term administration of pancuronium for ventilatory support of adults with ARDS may result in severe tetraparesis, with areflexia and atrophy of distal muscles. This adverse effect occurs rarely in paediatric intensive care units. We describe a case of tetraparesis after prolonged pancuronium infusion in a 9-month-old girl who experienced a severe bronchopneumonia caused by para-influenza virus, requiring endotracheal intubation and mechanical ventilation. To decrease chest wall rigidity, pancuronium was administered over 11 days, with a total dose of approximately 120 mg of pancuronium bromide. The day after discontinuation of the muscle relaxant she had a severe tetraplegia with areflexia, but normal head movements. Electromyography showed a normal neuromuscular transmission. She recovered from tetraplegia three months later. Other causes of peripheral neuropathy were eliminated. Electroencephalograms and head CT-scans were normal. The recovery pattern observed in our patient corresponded to the process of regeneration seen after axonal degeneration. It is suggested that these neuromuscular complications were caused by prolonged high-dosage pancuronium treatment, associated with corticosteroid and aminoglycoside administration.

Penetration of ciprofloxacin into bronchial secretions from mechanically ventilated patients with nosocomial bronchopneumonia

The aim of the study was to evaluate the penetration of ciprofloxacin into bronchial secretions from mechanically ventilated patients with nosocomial bronchopneumonia. For this purpose, in each patient studied, simultaneous serial blood and bronchial secretion samples were obtained over a 12-h period on days 2 and 4. Eight patients were included in the study. Ciprofloxacin was given at a dose of 200 mg over 30 min by using an automatic pump. Ciprofloxacin was measured by high-performance liquid chromatography. Peak levels of drug in serum were 2.95 +/- 1 mg/liter on day 2 and 2.43 +/- 0.7 mg/liter on day 4. Peak and trough levels in bronchial secretions were 0.95 +/- 0.51 and 0.21 +/- 0.12 mg/liter, respectively, on day 2 and 0.76 +/- 0.17 and 0.18 +/- 0.14 mg/liter, respectively, on day 4. The ratios of peak concentrations in bronchial secretions/serum were 0.32 +/- 0.11 and 0.33 +/- 0.06 on days 2 and 4, respectively. The ratios of the area under the concentration-time curve from 0 to 12 h (AUC0-12) for bronchial secretions/those for serum were 0.66 +/- 0.40 and 0.55 +/- 0.30 on days 2 and 4, respectively. A significant positive correlation was found on day 4 between the AUC0-12 for serum and the AUC0-12 for bronchial secretions. No significant correlations were found between peak values in serum and bronchial secretions.

Therapeutic process formalization in the treatment of respiratory failure in infants

The model described formalizes the therapeutic process developed in the Pediatric Intensive Care Unit (PICU) of Merate's Hospital as a support of medical decisions and as a continuous control of the adequacy of the ventilatory therapy. Causal and temporal structure of the keypoints of the treatment are represented by Petri Nets. The model could be utilised in different pathologies and for different clinical approach giving a meaningful organizational impact.

Simultaneous independent lung ventilation in pediatric patients

Current methods of ventilation do not allow adequate ventilation of the affected lungs in the presence of unilateral disease, e.g., unilateral atelectasis, diaphragmatic hernia, or lobar emphysema. Using a bilumen endotracheal tube and two independent ventilators, synchronized simultaneous independent lung ventilation (SILV) can be achieved. This technique provides a method of treating unilobar, unilateral, or multifocal lung disease effectively. This article describes the author's methodology and clinical experience with SILV.

Prophylactic and therapeutic application of Propionibacterium avidum KP-40 in swine and calves with acute enzootic bronchopneumonia

The usefulness of the prophylactic or therapeutic application of Propionibacterium avidum KP-40, a potent stimulator of the monocyte-macrophage-system, was demonstrated in piglets and calves. After a 3-month-period of observation PA-treated piglets showed a significantly improved development (decreased number of infections, gain of body weight). In piglets and calves the therapeutic use of PA together with oxytetracycline proved to be superior in the treatment of acute endemic enzootic bronchopneumonia (AEB) as compared to groups of animals receiving PA or oxytetracycline alone.