Septic arthritis of the knee caused by Edwardsiella tarda after a catfish puncture wound

Occupational Hazards Faced by Inland Fishers of Odisha State, India

OBJECTIVE

To identify occupational hazards and hazard control strategies adopted by inland fishers of Odisha state in India.

METHODS

Information on occupational hazards faced by fishers was collected by personal interviews with 90 riverine and reservoir fishers of Odisha. Through qualitative discussions with key informants and review of literature, a list of occupational hazards were prepared and classified into physical, ergonomics, psychosocial, and natural. Responses were quantified, and descriptive statistics were used for data analysis.

RESULTS

Occupational hazards faced by fishers were physical (94%), ergonomic (75%), psychosocial (50%), and natural (34%) in nature. Physical hazards include sharp fishing instruments, uneven surfaces, high temperatures, and wet/slippery areas on the vessel along with the presence of snake/leech/crocodile/fish fin rays. About 97% of reservoir and 90% of the riverine fishers reported physical hazards leading to cuts, fractures, dehydration, headache, sunburn, snakebite, leech bite, crocodile bite, and injuries due to fish fin rays. Heavy nature of work and force exerting activities caused pain in the upper back (50%), shoulders (45%), and lower back (41%). Regarding psychosocial hazard, stress (31%), and anxiety (23%) was reported. Common reasons for this were uncertainty in fish catch and extended working hours, causing tiredness, headache, dizziness, and fatigue. Natural hazards like cyclones, floods, and excessive rain caused financial loss and damage to fishing nets and boats. Regarding personal protective equipment (PPE), floating buoys were used by 26% of riverine and 43% of reservoir fishers to avoid drowning.

CONCLUSION

Occupational hazards in the inland fishing sector were identified as physical, ergonomic, psychosocial, and natural. No particular hazard control strategy was reported to be used. Integrating the occupational safety measures in the fisheries policies is thus needed.

Secreted in a Type III Secretion System-Dependent Manner, EsaH and EscE Are the Cochaperones of the T3SS Needle Protein EsaG of Edwardsiella piscicida

The intracellular EscE protein tightly controls the secretion of the type III secretion system (T3SS) middle and late substrates in Edwardsiella piscicida. However, the regulation of secretion by EscE is incompletely understood. In this work, we reveal that EscE interacts with EsaH and EsaG. The crystal structures of the EscE-EsaH complex and EscE-EsaG-EsaH complex were resolved at resolutions of 1.4 Å and 1.8 Å, respectively. EscE and EsaH form a hydrophobic groove to engulf the C-terminal region of EsaG (56 to 73 amino acids [aa]), serving as the cochaperones of T3SS needle protein EsaG in E. piscicida. V61, K62, M64, and M65 of EsaG play a pivotal role in maintaining the conformation of the ternary complex of EscE-EsaG-EsaH, thereby maintaining the stability of EsaG. An in vivo experiment revealed that EscE and EsaH stabilize each other, and both of them stabilize EsaG. Meanwhile, either EscE or EsaH can be secreted through the T3SS. The secondary structure of EsaH lacks the fourth and fifth α helices presented in its homologs PscG, YscG, and AscG. Insertion of the α4 and α5 helices of PscG or swapping the N-terminal 25 aa of PscG with those of EsaH starkly decreases the protein level of the chimeric EsaH, resulting in instability of EsaG and deactivation of the T3SS. To the best of our knowledge, these data represent the first reported structure of the T3SS needle complex of pathogens from Enterobacteriaceae and the first evidence for the secretion of T3SS needle chaperones. IMPORTANCE Edwardsiella piscicida causes severe hemorrhagic septicemia in fish. Inactivation of the type III secretion system (T3SS) increases its 50% lethal dose (LD₅₀) by ~10 times. The secretion of T3SS middle and late substrates in E. piscicida is tightly controlled by the intracellular steady-state protein level of EscE, but the mechanism is incompletely understood. In this study, EscE was found to interact with and stabilize EsaH in E. piscicida. The EscE-EsaH complex is structurally analogous to T3SS needle chaperones. Further study revealed that EscE and EsaH form a hydrophobic groove to engulf the C-terminal region of EsaG, serving as the cochaperones stabilizing the T3SS needle protein EsaG. Interestingly, both EscE and EsaH are secreted. Our study reveals that the EscE-EsaH complex controls T3SS protein secretion by stabilizing EsaG, whose secretion in turn leads to the secretion of the middle and late T3SS substrates.

Recreational and Commercial Catfishing Injuries: A Review of the Literature

Catfish injuries are increasingly common from the recreational activities of hobbyists, fishermen, and "noodling" enthusiasts as well as in the commercial catfish industry, most commonly in Brazil. Injuries can range from mild skin abrasions to life-threatening infections and tissue damage requiring urgent treatment. Most injuries and subsequent morbidity associated with catfish encounters involve the dorsal and pectoral fins. These injuries are most often lacerations involving the upper extremities. Deep, penetrating catfish spine injuries can lead to serious injuries, including arterial and nerve lacerations. Catfish venom is released when a spine is torn. The venom may cause reactions that include erythema, edema, local hemorrhage, tissue necrosis, and muscle contractions. When "finned" by a catfish, the fish's spine may separate from the fish, which can cause a foreign body embedment. Some injuries are not thought to be severe enough at the time of injury to require medical care, although symptoms may arise years later. In this literature review of catfishing injuries, references were obtained through a PubMed search of the following terms: catfish injuries, fishing, envenomation, spine, and aquatic infection. Articles were chosen for citation based on pertinence to the topic of catfishing.

Thoracic vertebral osteomyelitis following catfish spine impalement

Although rare, thoracic osteomyelitis can occur when toxins from a catfish spine impalement to the hand spread via the blood. This article describes diagnosis and management of this condition in a man who required hospitalization for debilitating back pain that developed 3 weeks after the initial injury.

Deep soft-tissue necrosis of the foot and ankle caused by catfish envenomation: a case report

Catfish envenomations represent a relatively rare cause of complications in podiatric medicine. We report a case of an unusual event eliciting a severe soft-tissue necrosis in a 21-year-old man and his complicated wound-healing process. This case reviews the potential complications of catfish envenomations.

Edwardsiellosis in fish: a brief review

Edwardsiellosis is one of the most important bacterial diseases in fish. Scientific work on this disease started more than forty years ago and numerous workers around the world are continually adding to the knowledge of the disease. In spite of this, not a single article that reviews the enormous scientific data thus generated is available in the English language. This article briefly discusses some of the recent research on edwardsiellosis, describing the pathogen's interaction with the host and environment, its pathogenesis and pathology as well as diagnostic, preventive and control measures.

Frequency and gravity of human envenomations caused by marine catfish (suborder siluroidei): a clinical and epidemiological study

INTRODUCTION AND OBJECTIVES

Catfish occur in marine and freshwater environments worldwide. They have three serrated venomous bony stings in the dorsal and pectoral fins that are used for defence against predators and are refilled by glandular tissues under the epithelium. However, some catfishes do not have poisonous glands next to the sting and cause traumatic wounds without poisoning. The objective of this study was to provide data for, and comment on, the epidemiological and clinical problems caused by marine catfish.

PATIENTS AND METHODS

The authors have observed, followed and documented 127 injuries caused by marine catfish stings during different phases of the envenoming over a time period of 8 years at three points along the Western Atlantic Ocean coast.

RESULTS

The patients presented intense pain during the acute phase of envenoming and complications, such as bacterial and fungi infections and retention of bony fragments, in the later phase. Immersion of the affected extremity in hot water was used in about 20% of cases with excellent results.

DISCUSSION

Injuries caused by marine catfish are common (about 20% of injuries caused by marine animals in a series of more than 700 injuries recorded by the author) and cause intense pain and later complications. Immersion of the affected extremity in hot water results in improvement in the acute phase, but does not prevent the appearance of secondary infection or foreign body reactions.

Envenomations

Numerous types of envenomations may be encountered by health care workers depending on where in North America they work. Clinicians should be familiar with the animals in their region that may lead to envenomation.A rational approach with use of poison center or medical toxicology consultation services ensures that cases are managed appropriately.

Extraintestinal manifestations of Edwardsiella tarda infection

Summary Edwardsiella tarda, a member of the family Enterobacteriaceae, is a rare human pathogen. Gastroenteritis is the most frequently reported manifestation of E. tarda infection. In contrast, extraintestinal infection with E. tarda has rarely been reported. This study made a retrospective case and microbiological data review of patients with extraintestinal E. tarda infections to further understand this disease. This study retrospectively reviewed the charts of all isolates of E. tarda cultures from clinical specimens other than faeces at Chang Gung Memorial Hospital, Taoyuan, Taiwan from October 1998 through December 2001. Edwardsiella tarda was isolated from 22 clinical specimens from 22 hospitalised patients (13 females and nine males). The extraintestinal manifestations of E. tarda infection included biliary tract infection, bacteraemia, skin and soft tissue infection, liver abscess, peritonitis, intra-abdominal abscess, and tubo-ovarian abscess. The major underlying diseases predisposing to E. tarda extraintestinal infection were hepatobiliary diseases, malignancy and diabetes mellitus. The overall mortality rate of E. tarda extraintestinal infection in the present series was 22.7% (5/22), and four (40%) of 10 patients with bacteraemia expired. Although rare, human E. tarda extraintestinal infections can have diverse clinical manifestations and moreover may cause severe and life-threatening infections. Consequently, E. tarda should be considered a potentially important pathogen.

Structural characterization of the O-polysaccharide antigen of Edwardsiella tarda MT 108

Edwardsiella tarda, a Gram-negative bacterium, is an important cause of hemorrhagic septicemia in fish and also of gastro- and extraintestinal infections in humans. The lipopolysaccharide produced by the fish pathogenic strain E. tarda MT 108 was isolated and the structure of its antigenic O-polysaccharide component determined by the application of chemical analyses, high-resolution 1D and 2D nuclear magnetic resonance spectroscopy, and mass spectrometry. The polysaccharide was found to be a polymer of a repeating pentasaccharide unit composed of 2-acetamido-2-deoxy-D-glucose (D-GlcNAc), 2-acetamido-2-deoxy-D-galactose (D-GalNAc), D-galactose (D-Gal), L-rhamnose (L-Rha), D-galacturonic acid (D-GalA) and (2S,3R)-threonine (1:1:1:1:1:1) having the structure: [structure: see text].

Functional genomics approach to the identification of virulence genes involved in Edwardsiella tarda pathogenesis

Edwardsiella tarda is an important cause of hemorrhagic septicemia in fish and also of gastro- and extraintestinal infections in humans. Here, we report the identification of 14 virulence genes of pathogenic E. tarda that are essential for disseminated infection, via a genome-wide analysis. We screened 490 alkaline phosphatase fusion mutants from a library of 450,000 TnphoA transconjugants derived from strain PPD130/91, using fish as an infection model. Compared to the wild type, 15 mutants showed significant decreases in virulence. Six mutants had insertions in the known virulence-related genes, namely, fimA, gadB, katB, pstS, pstC, and ssrB. Some mutants corresponded to known genes (astA, isor, and ompS2) that had not been previously shown to be involved in pathogenesis, and three had insertions in two novel genes. In vivo infection kinetics experiments confirmed the inability of these attenuated mutants to proliferate and cause fatal infection in fish. Screening for the presence of the above-described virulence genes in six virulent and seven avirulent strains of E. tarda indicated that seven of the genes were specific to pathogenic E. tarda. The genes identified here may be used to develop vaccines and diagnostic kits as well as for further studying the pathogenesis of E. tarda and other pathogenic bacteria.

Topically acquired bacterial zoonoses from fish: a review

The main pathogens acquired topically from fish (through spine puncture or open wounds) are Aeromonas hydrophila, Edwardsiella tarda, Erysipelothrix rhusiopathiae, Mycobacterium marinum, Streptococcus iniae, Vibrio vulnificus and Vibrio damsela. S. iniae has recently emerged as a public health hazard associated with aquaculture, and M. marinum often infects home aquarium hobbyists. With the expansion of aquaculture and popularity of recreational fishing in Australia, medical practitioners can expect to see more infections of this nature. Diagnosis and treatment may be difficult, especially in view of emerging antibiotic resistance in fish pathogens.