causative agents
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2024 ◽  
Vol 84 ◽  
Author(s):  
L. Tooba ◽  
A. Shahzad ◽  
M. Zahid ◽  
R. Muhammad ◽  
I. Anam ◽  
...  

Abstract Pakistan is an agricultural country and fisheries play a very important role in the economic development of the country. Different diseases are prevalent in Pakistani fish but information related to the causative agents is not well-known. Keeping in view the significance of bacterial pathogens as the causative agents of multiple fish diseases, the present study was conducted for identification, characterization and analysis of virulence genes of Aeromonas spp. isolated from diseased fishes. A total of fifty fish samples having multiple clinical indications were collected from different fish farms of district Kasur, Punjab Pakistan. For isolation of Aeromonas spp. samples were enriched and inoculated on Aeromonas isolation medium. Isolates were identified and characterized by different biochemical tests, Analytical Profile Index (API) 20E kit and Polymerase Chain Reaction (PCR) assays. All isolates were screened for three putative virulence genes including aerolysin (aer), haemolysin (hyl) and heat labile cytotonic enterotoxin (alt). Seven isolates of Aeromonas (A.) hydrophila were retrieved and identified based on API 20E. These isolates were further confirmed as A. hydrophila on the basis of PCR assays. Three isolates were detected positive for the presence of virulence genes (alt and hyl). Whereas aerolysin (aer) gene was not present in any of A. hydrophila isolates. The present study confirmed A. hydrophila as the causative agent of epizootic ulcerative syndrome and motile Aeromonas septicemia in fish farms of district Kasur, Punjab Pakistan. Moreover, detection of two virulence genes (alt and hyl) in A. hydrophila isolates is a threat for fish consumers of study area.


2024 ◽  
Vol 84 ◽  
Author(s):  
Q. Rahman ◽  
M. S. Nadeem ◽  
M. Altaf ◽  
S. H. Khan ◽  
A. Saeed ◽  
...  

Abstract Birds are among the best bio-indicators, which can guide us to recognize some of the main conservation concerns in ecosystems. Anthropogenic impacts such as deforestation, habitat degradation, modification of landscapes, and decreased quality of habitats are major threats to bird diversity. The present study was designed to detect anthropogenic causative agents that act on waterbird diversity in Tarbella Dam, Indus River, Pakistan. Waterbird censuses were carried out from March 2019 to February 2020 in multiple areas around the dam. A total of 2990 waterbirds representing 63 species were recorded. We detected the highest waterbird richness and diversity at Pehure whereas the highest density was recorded at Kabbal. Human activity impacts seemed to be the main factor determining the waterbird communities as waterbirds were negatively correlated with the greatest anthropogenic impacts. Waterbirds seem to respond rapidly to human disturbance.


2022 ◽  
Author(s):  
Amal A Kokandi

Abstract Introduction:Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are rare, life-threatening conditions caused mainly by drugs. Their management relies on the withdrawal of the culprit medication and supportive measures. Different pharmacotherapies have varied effects. However, data related to TEN and SJS in Saudi is limited. This study aimed to identify the causative agents, associated factors, and outcomes of TEN/SJS cases admitted to a teaching hospital (King Abdulaziz University) in Jeddah during the last 10 years.Methods: We retrospectively analyzed the data of TEN/SJS patients admitted to the hospital over the last 10 years.Results: We identified 12 patients with TEN/SJS. Of these, nine survived the condition and were discharged. The culprit medication was identified in eight of them, including antibiotics in six cases and Tegretol and allopurinol in one case each. Most of the patients received systemic steroids and intravenous immunoglobulins.Conclusion: TEN/SJS is mainly caused by medications of which antibiotics are the most implicated. Consistent with other studies, the mortality rate associated with TEN/SJS in Saudi is 25%. Limitations: restricted to a single center and small sample size.


Vaccines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 123
Author(s):  
Reginaldo G. Bastos ◽  
Heba F. Alzan ◽  
Vignesh A. Rathinasamy ◽  
Brian M. Cooke ◽  
Odir A. Dellagostin ◽  
...  

Babesiosis is a disease caused by tickborne hemoprotozoan apicomplexan parasites of the genus Babesia that negatively impacts public health and food security worldwide. Development of effective and sustainable vaccines against babesiosis is currently hindered in part by the absence of definitive host correlates of protection. Despite that, studies in Babesia microti and Babesia bovis, major causative agents of human and bovine babesiosis, respectively, suggest that early activation of innate immune responses is crucial for vertebrates to survive acute infection. Trained immunity (TI) is defined as the development of memory in vertebrate innate immune cells, allowing more efficient responses to subsequent specific and non-specific challenges. Considering that Mycobacterium bovis bacillus Calmette-Guerin (BCG), a widely used anti-tuberculosis attenuated vaccine, induces strong TI pro-inflammatory responses, we hypothesize that BCG TI may protect vertebrates against acute babesiosis. This premise is supported by early investigations demonstrating that BCG inoculation protects mice against experimental B. microti infection and recent observations that BCG vaccination decreases the severity of malaria in children infected with Plasmodium falciparum, a Babesia-related parasite. We also discuss the potential use of TI in conjunction with recombinant BCG vaccines expressing Babesia immunogens. In conclusion, by concentrating on human and bovine babesiosis, herein we intend to raise awareness of BCG TI as a strategy to efficiently control Babesia infection.


2022 ◽  
Vol 2022 ◽  
pp. 1-3
Author(s):  
Krystal Hasel ◽  
Ahlaa Salim ◽  
Paul Adjei ◽  
Jeremy D. Gradon

Intra-abdominal abscesses mostly derive from the intra-abdominal viscera. Campylobacter spp. are Gram-negative rods which are known to cause oral infections but rarely have been documented to cause extra-intestinal infections resulting in abscesses. We report an atypical case of Campylobacter rectus (C. rectus) and Peptostreptococcus spp. bacteria isolated from a perinephric abscess presenting as abdominal pain. Abscesses originating from outside the gastrointestinal tract have been reported in other similar case reports infecting the head, brain, and thoracic wall amongst others. The potential source and development of such a Campylobacter infection could be due to multiple hypotheses. This is a first case report of perinephric abscess development. Studies have suggested person-to-person (fecal-oral) transmission along with insects serving as primary reservoirs. Seeding of bacteria through infections in the oral cavity or through infections in the bowel microperforations has also been considered as plausible reasons. Since C. rectus has been isolated in such rare instances, it should be kept in mind when considering differential diagnosis of potential causative agents for extra-oral infections such as invasive abscess formations.


2022 ◽  
Vol 10 (1) ◽  
pp. 166
Author(s):  
Andrea Springer ◽  
Daniela Jordan ◽  
Antje Glass ◽  
Olaf Kahl ◽  
Volker Fingerle ◽  
...  

In Europe, Ixodes ricinus plays a major role as a vector of Borrelia burgdorferi sensu lato (s.l.) spirochaetes, the causative agents of Lyme borreliosis, among other pathogens. In unfed ticks, Borrelia spirochaetes experience prolonged nutrient restriction. However, only few studies exist with regard to Borrelia infections in unfed ticks of different physiological ages. Changing body dimensions of unfed ticks, due to the consumption of energy reserves, allow physiological age estimation. The present study investigated the relationship of morphometric age with Borrelia prevalence and spirochaete load in 1882 questing I. ricinus nymphs, collected at two different locations in northern Germany in 2020. In addition, Borrelia species composition was investigated by employing a reverse line blot (RLB) probe panel suitable for the detection of ten different B. burgdorferi s.l. species, as well as the relapsing-fever spirochaete B. miyamotoi. Overall, Borrelia prevalence was 25.8% (485/1882). Whilst there was no statistically significant difference in Borrelia prevalence between the different morphometric age groups, Borrelia infection intensity as determined by probe-based quantitative real-time PCR significantly declined with increasing morphometric age. Borrelia species differentiation by RLB was successful in 29.5% of positive ticks, and revealed B. afzelii as the dominating species (65.0% of the differentiated infections). Additionally, B. garinii, B. valaisiana, B. burgdorferi sensu stricto, B. spielmanii, and B. miyamotoi were detected.


Author(s):  
Angelina Wójcik-Fatla ◽  
Barbara Mackiewicz ◽  
Anna Sawczyn-Domańska ◽  
Jacek Sroka ◽  
Jan Siwiec ◽  
...  

Abstract Occurrence Gram-negative bacteria occur commonly in the inner tissues of stored coniferous and deciduous timber, showing a marked variation in numbers. The greatest maximal numbers are found in the sapwood of coniferous timber. The common constituents of the Gram-negative biota are potentially pathogenic species of Enterobacteriaceae family of the genera Rahnella, Pantoea, Enterobacter, and Klebsiella. The air of wood-processing facilities is polluted with the wood-borne Gram-negative bacteria and produced by them endotoxin, as demonstrated worldwide by numerous studies. Effects There are three potential pathways of the pathogenic impact of wood-borne Gram-negative bacteria on exposed woodworkers: allergic, immunotoxic, and infectious. Allergic impact has been underestimated for a long time with relation to Gram-negative bacteria. Hopefully, the recent demonstration of the first documented case of hypersensitivity pneumonitis (HP) in woodworkers caused by Pantoea agglomerans which developed in extremely large quantities in birch sapwood, would speed up finding of new wood-related cases of HP caused by Gram-negative bacteria. The second pathway is associated with endotoxin, exerting strong immunotoxic (excessively immunostimulative) action. It has been demonstrated that endotoxin is released into wood dust in the form of nano-sized microvesicles, by peeling off the outer membrane of bacteria. Endotoxin microvesicles are easily inhaled by humans together with dust because of small dimensions and aerodynamic shape. Afterwards, they cause a nonspecific activation of lung macrophages, which release numerous inflammatory mediators causing an inflammatory lung reaction, chest tightness, fever, gas exchange disorders, and bronchospasm, without radiographic changes. The resulting disease is known as “Organic Dust Toxic Syndrome” or “toxic pneumonitis.” The potential third pathway of pathogenic impact is infection. The suspected species is Klebsiella pneumoniae that may occur commonly in wood dust; however, until now this pathway has not been confirmed. Conclusion Summarizing, Gram-negative bacteria-inhabiting timber should be considered, besides filamentous fungi and actinobacteria, as important risk factors of occupational disease in woodworkers that could be either HP with allergenic background or toxic pneumonitis elicited by endotoxin.


2022 ◽  
Vol 2022 ◽  
pp. 1-3
Author(s):  
Taro Fukuta ◽  
Yoshihiko Kawano ◽  
Maiko Ikeda ◽  
Jun-ichi Kawada ◽  
Yoshinori Ito ◽  
...  

Human parvovirus B19 (PVB19) infection causes neurological manifestations, including encephalitis, meningitis, and neuropathy, but facial nerve palsy is rare. Moreover, no case of facial nerve palsy related to PVB19 infection that was diagnosed by PCR and serology has been reported. A 19-month-old boy without the medical history developed facial nerve palsy and was treated with prednisolone and valacyclovir. On the 19th day, erythema appeared on his body, and the PVB19-specific IgM and PVB19 DNA were detected in the serum, leading to the diagnosis of infectious erythema associated with PVB19 infection. This case indicates that PVB19 may be one of the causative agents of facial nerve palsy.


2022 ◽  
Vol 98 (6) ◽  
pp. 664-670
Author(s):  
N. F. Timchenko ◽  
М. G. Еliseikina ◽  
G. K. Tchernoded ◽  
O. V. Grishchenko ◽  
А. V. Rakov ◽  
...  

Background. A significant role in the ecology of the sapronotic pathogens Yersinia pseudotuberculosis and Listeria monocytogenes and in the epidemiology of the infections they cause is played by land plants used for food. These microorganisms are often found on plant substrates, they multiply on various vegetable and root crops. In this regard, it is relevant to study the viability and biological activity of Y. pseudotuberculosis and L. monocytogenes in contact with various land plants, including those that are not eaten, but are used in medicine.Aim. Study of the interaction of sapronotic pathogens Y. pseudotuberculosis and L. monocytogenes with callus cultures of the land plant Lithospermum erythrorhizon Siebold et Zucc.Materials and methods. The studies included strains of Y. pseudotuberculosis 512 serotype 1b, pYV+, 82MD+ and L. monocytogenes NCTC (4b) 10527 from the Collection of Somov Institute of Epidemiology and Microbiology, and cell culture from the roots of red-root gromwell Lithospermum erythrorhizon line VC-39 (from the Collection of FSC of the East Asia Terrestrial Biodiversity FEB RAS).Before the study, Y. pseudotuberculosis and L . monocytogenes were cultured 18–20 hours on nutrient agar pH 7.1–7.2. A working dilution of microorganisms was prepared (106 micobial cells per 1 ml) and applied at a dose of 100 μl to the surface of plant calli. Material samples were taken in dynamics after 3 and 14 days and prepared for scanning electron microscopy.Results. Y. pseudotuberculosis and L. monocytogenes formed biofilms on the surface of plant cells within 3 days after the start of the experiment. It was noted that Y. pseudotuberculosis destroyed the components of the plant cell membrane.Conclusion. New data obtained during the study expand the understanding of environments and forms of habitation, as well as the potential for pathogenicity of sapronotic pathogens in the environment.


2022 ◽  
pp. 30-33
Author(s):  
I. V. Shipitsyna ◽  
E. V. Osipova

Introduction. To date, a significant number of works have been published devoted to the analysis of the sensitivity of the leading causative agents of osteomyelitis to modern drugs, however, in the available literature there are no data on a comparative analysis of the antibiotic resistance of bacteria isolated from the osteomyelitis focus from the association and in monoculture. Purpose of the work: to compare the resistance profiles of the leading causative agents of osteomyelitis, depending on the bacterial composition of the focus of infection.Materials and methods. The study included 216 clinical isolates, of which 114 were isolated as part of two-component associations, 102 – in a monoculture from pathological material in patients with chronic osteomyelitis who were treated in the purulent department of National Medical Scientific Centre of Traumatology and Orthopedics n.a. academician G.E. Ilizarov (Kurgan, Russia) from 2018 to 2020. To analyze the resistance profiles, depending on the type of microorganism, modern drugs used in the clinic for the treatment of osteomyelitis were taken into account.Results and its discussion. Effective drugs against P. aeruginosa strains isolated from the association were polymyxin and meropenem, and in monoculture–polymyxin, piperacillin/tazobactam, tobramycin; in relation to strains of K. pneumoniae isolated from the association, it was imipenem, in monoculture – amikacin. S. aureus strains isolated both from the association and in monoculture were highly susceptible to antibacterial drugs.Conclusion. The analysis of the sensitivity of the leading causative agents of osteomyelitis, isolated in monoculture and from the association, to the antibacterial drugs used in the clinic, showed significant differences in the resistance profiles between the groups: for S. aureus strains, 4 antibiotics tested out of 13, for P. aeruginosa strains – 7 out of 13, for K. pneumoniae strains – 12 out of 16. The tested antibacterial drugs were less active against P. aeruginosa and S. aureus strains isolated from associations. In contrast, the percentage of resistant strains of K. pneumoniae was higher among monocultures.


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