Pathogen variation across time and space: sequencing to characterize Mannheimia haemolytica diversity

2014 ◽  
Vol 15 (2) ◽  
pp. 169-171 ◽  
Author(s):  
Michael L. Clawson ◽  
Robert W. Murray

AbstractBovine respiratory disease complex (BRDC) is a major animal health and economic issue that affects cattle industries worldwide. Within the USA, the beef cattle industry loses up to an estimated 1 billion dollars a year due to BRDC. There are many contributors to BRDC, including environmental stressors and viral and/or bacterial infections. One species of bacteria in particular, Mannheimia haemolytica, is recognized as the major cause of severe fibrinonecrotic pneumonia in cattle. M. haemolytica is an opportunistic pathogen that normally populates the upper respiratory tract of cattle, and invades the lower respiratory tract in stressed and/or virally infected cattle by mechanisms that are not completely understood. However, not all M. haemolytica appear to be equally pathogenic to cattle. Thus, a test could be developed to distinguish M. haemolytica genetic subtypes by their propensity to cause respiratory disease, allowing isolation and/or treatment of cattle harboring strains with an increased propensity to cause disease. To that end, the genomes of over 300 M. haemolytica strains are being sequenced.

2020 ◽  
Author(s):  
Wenfang Guo ◽  
Letai Yi ◽  
Peng Wang ◽  
Baojun Wang ◽  
Minhui Li

Abstract Background Some previous studies have examined the effects of temperature, humidity, wind speed and atmospheric pressure on children morbidity, but few studies have evaluated health effects of combined effect of various meteorological factors. The purpose of this study was to assess the effect of daily changes in meteorological factors and their comprehensive effects on children’s respiratory disease hospitalizations for different ages, genders and subtypes in Baotou, China. Methods Generalized additive models and distributed lag non-linear models were constructed to simultaneously assess the exposure–response associations between daily admission counts of children with respiratory diseases and daily net effective temperature and other meteorological factors as well as their lag dependencies. Results In general, the cumulative meteorological factors had greater effects on lower respiratory tract infections than upper respiratory tract infections (RR: temperature [4.2 vs. 2.7]; wind speed [3.1 vs. 2.5]; humidity [1.8 vs. 1.3]). The effects on children over 3 years old were greater than those on children aged 0–3 years (OR: temperature [4.4 vs. 1.3]; wind speed [4.4 vs. 1.5]), while the effects on female children were greater than those on male children (OR: temperature [2.6 vs. 1.8]; wind speed [3.3 vs. 1.6]). However, some differences were observed between groups with regard to the effect of humidity. Hence, the net effective temperature was calculated using comprehensive meteorological factors, and the influence range value and peak value of each group were determined. Conclusions The influence of meteorological factors on children’s respiratory disease hospitalizations shows different characteristics in different subgroups. Hence, the net effective temperature was calculated using the comprehensive meteorological factors, and the influence range and peak value of each group were determined so as to recommend the corresponding measures accordingly.


2002 ◽  
Vol 70 (2) ◽  
pp. 481-490 ◽  
Author(s):  
Susan L. Brockmeier ◽  
Karen B. Register ◽  
Tibor Magyar ◽  
Alistair J. Lax ◽  
Gillian D. Pullinger ◽  
...  

ABSTRACT Bordetella bronchiseptica is one of the etiologic agents causing atrophic rhinitis and pneumonia in swine. It produces several purported virulence factors, including the dermonecrotic toxin (DNT), which has been implicated in the turbinate atrophy seen in cases of atrophic rhinitis. The purpose of these experiments was to clarify the role of this toxin in respiratory disease by comparing the pathogenicity in swine of two isogenic dnt mutants to their virulent DNT+ parent strains. Two separate experiments were performed, one with each of the mutant-parent pairs. One-week-old cesarean-derived, colostrum-deprived pigs were inoculated intranasally with the parent strain, the dnt mutant strain, or phosphate-buffered saline. Weekly nasal washes were performed to monitor colonization of the nasal cavity, and the pigs were euthanized 4 weeks after inoculation to determine colonization of tissues and to examine the respiratory tract for pathology. There was evidence that colonization of the upper respiratory tract, but not the lower respiratory tract, was slightly greater for the parent strains than for the dnt mutants. Moderate turbinate atrophy and bronchopneumonia were found in most pigs given the parent strains, while there was no turbinate atrophy or pneumonia in pigs challenged with the dnt mutant strains. Therefore, production of DNT by B. bronchiseptica is necessary to produce the lesions of turbinate atrophy and bronchopneumonia in pigs infected with this organism.


2019 ◽  
Author(s):  
Laura K Certain ◽  
Miriam B Barshak

Upper respiratory tract infections are the most common maladies experienced by humankind.1 The majority are caused by respiratory viruses. A Dutch case-controlled study of primary care patients with acute respiratory tract infections found that viruses accounted for 58% of cases; rhinovirus was the most common (24%), followed by influenza virus type A (11%) and corona­viruses (7%). Group A streptococcus (GAS) was responsible for 11%, and 3% of patients had mixed infections. Potential pathogens were detected in 30% of control patients who were free of acute respiratory symptoms; rhinovirus was the most common.2 Given the increasing problem of antibiotic resistance and the increasing awareness of the importance of a healthy microbiome, antibiotic use for upper respiratory infections should be reserved for those patients with clear indications for treatment. A recent study of adult outpatient visits in the United States found that respiratory complaints accounted for 150 antibiotic prescriptions per 1,000 population annually, yet the expected “appropriate” rate would be 45.3 In other words, most antibiotic prescriptions for these complaints are unnecessary. Similarly, a study in the United Kingdom found that general practitioners prescribed antibiotics to about half of all patients presenting with an upper respiratory infection, even though most of these infections are viral.4 This review contains 5 figures, 16 tables, and 82 references. Keywords: infection, airway, sinusitis, otitis media, otitis externa, pharyngitis, epiglottitis, abscess


2020 ◽  
Vol 187 (5) ◽  
pp. 189-189 ◽  
Author(s):  
Joana D Fonseca ◽  
Daphne E Mavrides ◽  
Alice L Morgan ◽  
Jea G Na ◽  
Peter A Graham ◽  
...  

IntroductionRespiratory diseases account for the highest number of clinical problems in horses compared with other body systems. While microbiological culture and sensitivity testing is essential for certain cases, knowledge of the most likely bacterial agents and their susceptibilities is necessary to inform empirical antibiotic choices.MethodsA retrospective study of microbiological and cytological results from upper and lower respiratory samples (n=615) processed in a commercial laboratory between 2002 and 2012 was carried out. A further study of lower respiratory samples from horses with clinical signs of lower respiratory disease from May to June 2012 was undertaken.ResultsBoth studies revealed Streptococcus equi subspecies zooepidemicus, Pseudomonas aeruginosa, Pasteurella species, Escherichia coli and Bordetella bronchiseptica as the most frequently isolated species. S equi subspecies zooepidemicus and subspecies equi were susceptible to ceftiofur (100 per cent) and erythromycin (99 per cent). Resistance to penicillin (12.5 per cent of S equi subspecies equi from upper respiratory tract samples) and tetracycline (62.7 per cent) was also detected. Gram-negative isolates showed resistance to gentamicin, trimethoprim-sulfamethoxazole and tetracycline but susceptibility to enrofloxacin (except Pseudomonas species, where 46.2 per cent were resistant). Multiple drug resistance was detected in 1 per cent of isolates.ConclusionResistance to first-choice antibiotics in common equine respiratory tract bacteria was noted and warrants continued monitoring of their susceptibility profiles. This can provide information to clinicians about the best empirical antimicrobial choices against certain pathogenic bacteria and help guide antibiotic stewardship efforts to converse their efficacy.


2019 ◽  
Vol 36 (S 02) ◽  
pp. S54-S57 ◽  
Author(s):  
Ki Wook Yun ◽  
Rebecca Wallihan ◽  
Alexis Juergensen ◽  
Asuncion Mejias ◽  
Octavio Ramilo

AbstractCommunity-acquired pneumonia (CAP) is the leading cause of death in children < 5 years of age worldwide. It is also one of the most frequent infectious diseases in children, leading to large antibiotic use and hospitalization even in the industrialized countries. However, the optimal management of CAP in children is still not well defined. Currently, respiratory viruses are considered the most frequent etiologic agents, but detection of viruses in the upper respiratory tract does not guarantee causation of pneumonia, nor precludes the presence of a bacterial pathogen. In both the upper and lower respiratory tract, respiratory viruses and pathogenic bacteria interact. Emerging evidence indicates that dual viral–bacterial infections function synergistically in many cases and together likely enhance the severity of CAP. Therefore, new and advanced technologies capable of sensitively and specifically discriminating viral, bacterial, and viral–bacterial coinfections are needed. Instead of focusing on the pathogen, analysis of host immune transcriptome profiles from children with CAP can potentially offer diagnostic signatures, help to assess disease severity, and eventually, prognostic indicators. An optimized management strategy by using molecular pathogen testing and transcriptome profiling will facilitate prompt, more appropriate, and targeted therapies, which in turn will lead to improved clinical outcomes in children with CAP.


2017 ◽  
Vol 29 (4) ◽  
pp. 450-456 ◽  
Author(s):  
Francisco R. Carvallo ◽  
Francisco A. Uzal ◽  
Santiago S. Diab ◽  
Ashley E. Hill ◽  
Rick M. Arthur

Respiratory diseases have a major impact on racehorses in training and are often cited as the second most common reason of horses failing to perform. Cases were submitted by the California Horse Racing Board to the California Animal Health and Food Safety laboratory for postmortem examination between January 1, 2005 and December 31, 2014. We determined the demographics of racehorses with fatal pneumonia, characterized the pathologic findings in animals with a postmortem diagnosis of respiratory infection, and determined the most significant pathogens associated with lower respiratory tract disease. We analyzed autopsy reports from 83 horses with a diagnosis of pneumonia, bronchopneumonia, and/or pleuropneumonia. The most common presentation was pleuropneumonia (71% of cases), with extensive areas of lytic necrosis and abscesses of the pulmonary parenchyma. Streptococcus equi ssp. zooepidemicus, a normal mucosal commensal of the upper respiratory tract of healthy horses, was the most commonly isolated organism (72% of cases), either in pure culture or accompanied by other aerobic or anaerobic bacteria. Its presence in the pulmonary parenchyma is associated with severe and extensive damage to the lung. Furthermore, this agent has zoonotic potential, which stresses the importance of early detection and proper management of cases of pneumonia in racehorses.


2020 ◽  
Author(s):  
Agata Skrzat-Klapaczynska ◽  
Marcin Paciorek ◽  
Ewa Firlag-Burkacka ◽  
Andrzej Horban ◽  
Justyna Dominika Kowalska

Background The risk and characteristics of upper respiratory tract (URT) bacterial infections (URT-BI) among HIV (+) patients is understudied. We analyzed factors associated with its occurrence and the spectrum of pathogens among patients routinely followed at the HIV Out-Patient Clinic in Warsaw. Methods All symptomatic HIV (+) patients with available URT swab culture were included into analyses. Patients were followed from the day of registration in the clinic until first positive URT swab culture or last clinical visit. Cox proportional hazard models were used to identify factors associated with positive URT swabs culture (those with p<0.1 in univariate included into multivariable). Results In total 474 patients were included into the analyses, 166 with positive URT swab. In general 416 (87.8%) patients were male, 342 (72.1%) were infected through MSM contact, 253 (53.4%) were on antiretroviral therapy. Median follow-up time was 3.4 (1.3-5.7) years, age 35.2 (30.6-42.6) years and CD4+ count 528 (400-685) cells/μl. The most common pathogens were S. aureus (40.4%) and S. pyogenes (13.9%) (Table 1). Patients with URT-BI were more likely to be MSM (68.5% vs 78.9%; p<0.016), have detectable viral load (20.9% vs 12.0%; p<0.0001) and CD4+ cell count <500 cells/μl (55.2% vs 39.0%; p=0.003) (Table 2). In multivariate survival analyses detectable viral load (HR3.13; 95%Cl: 2.34-4.19) and MSM (1.63;1.09-2.42) were increasing, but older age (0.63;0.58-0.69, per 5 years older) and higher CD4+ count (0.90;0.85-0.95, per 100 cells/μl) decreasing the risk of URT-BI (Table 2). Conclusions URT BI are common among HIV (+) positive patients with high CD4+ count. Similarly to general population most common patogens are S. aureus and S. pyogenes. Risk factors identified in multivariate survival analysis indicate that younger MSM patients with detectable HIV viral load are at highest risk. In clinical practice this group of patients requires special attention.


2021 ◽  
pp. 83-91
Author(s):  
G. N. Nikiforova ◽  
G. G. Asriyan ◽  
M. M. Gurkova ◽  
P. S. Artamonova

Bacteriophages - viruses infecting bacteria are the largest known group of viruses, which in their structure mainly have doublestranded genomic DNA, but among them there are also groups with double-stranded RNA and single-stranded DNA and RNA. The total population is about 1031–1032 phages, they play an essential role in the regulation of the world’s number of bacteria. The rather complex and diverse interaction of these representatives of the microcosm continues throughout the history of their existence on our planet. The question of the use of bacteriophages in the treatment of patients with various bacterial infections still remains completely unexplored. The very idea of using these microorganisms for therapeutic purposes dates back to the First World War, when the French biologist and researcher Felix d’Hérelle discovered a special type of «bacteria-eating» viruses, on the basis of which he created drugs for the treatment of patients with dysentery. To date, a fairly large clinical experience has been accumulated in the use of phage preparations in the treatment of infectious and inflammatory diseases of the respiratory, gastrointestinal, urogenital tract, as well as in the therapy and prevention of purulent-septic processes and nosocomial infections. The mucous membrane of the upper respiratory tract is the first line of defense against various respiratory pathogens. The ability of bacteriophages to attach to the surface layer of mucus - mucin, forming an antibacterial protection of the mucous membrane and thus reducing the level of colonization of mucus by bacterial pathogens, determines their effective use in the treatment and prevention of inflammatory diseases of the upper respiratory tract. Due to certain unique properties of bacteriophages, peculiarities of vital activity and interaction with a bacterial cell, their use seems to be promising for the treatment of patients with infectious diseases of the upper respiratory tract.


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