Simultaneous detection of multiple bacterial and viral aquatic pathogens using a fluorogenic loop-mediated isothermal amplification-based dual-sample microfluidic chip.

Rapid and user-friendly diagnostic tests are necessary for early diagnosis and immediate detection of diseases, particularly for on-site screening of pathogenic microorganisms in aquaculture. In this study, we developed a dual-sample microfluidic chip integrated with a real-time fluorogenic loop-mediated isothermal amplification assay (dual-sample on-chip LAMP) to simultaneously detect 10 pathogenic microorganisms, that is Aeromonas hydrophila, Edwardsiella tarda, Vibrio harveyi, V. alginolyticus, V. anguillarum, V. parahaemolyticus, V. vulnificus, infectious hypodermal and haematopoietic necrosis virus, infectious spleen and kidney necrosis virus, and white spot syndrome virus. This on-chip LAMP provided a nearly automated protocol that can analyse two samples simultaneously, and the tests achieved limits of detection (LOD) ranging from 100 to 10-1  pg/µl for genomic DNA of tested bacteria and 10-4 to 10-5  pg/µl for recombinant plasmid DNA of tested viruses, with run times averaging less than 30 min. The coefficient of variation for the time-to-positive value was less than 10%, reflecting a robust reproducibility. The clinical sensitivity and specificity were 93.52% and 85.53%, respectively, compared to conventional microbiological or clinical methods. The on-chip LAMP assay provides an effective dual-sample and multiple pathogen analysis, and thus would be applicable to on-site detection and routine monitoring of multiple pathogens in aquaculture.

Surgical site infection caused by Aeromonas hydrophila presenting as necrotizing soft tissue infection after esophagectomy.

Several virulence factors of Aeromonas such as hemolysin, proteases and lipases have been characterized. The relationship between these virulence factors and disease remains unclear. A 71-year-old man underwent thoracoscopic esophagectomy, lymph node dissection and Roux-en-Y reconstruction for esophageal cancer. On postoperative day 1, redness around the wound on the thoracic abdominal wall gradually enlarged and necrosis became apparent with septic shock. Necrotizing soft tissue infection was suspected and emergency surgical debridement was performed. Blood and wound cultures were positive for Aeromonas hydrophila. The strain was found to have hemolytic activity, proteolytic activity and extremely high elastolytic activity. In addition, the strain actively produced elastolytic metalloprotease, which may contribute to extensive tissue necrosis.

Roles of three TonB systems in the iron utilization and virulence of the Aeromonas hydrophila Chinese epidemic strain NJ-35.

The TonB system functions in iron transport and has been identified in certain Gram-negative bacteria. Recently, we reported three TonB systems in the Aeromonas hydrophila Chinese epidemic strain NJ-35, but the functions of these systems have not been thoroughly elucidated to date. In this study, we investigated the role of these TonB systems in A. hydrophila iron utilization and virulence. We found that tonB1 and tonB2 were preferentially transcribed in iron-chelated conditions, where gene expression levels were approximately 8- and 68-fold higher compared with iron-rich conditions, respectively; tonB3 was consistently transcribed at a low level under iron-repleted and iron-depleted conditions. Only the TonB2 system was required to utilize iron-binding proteins. The tonB123 mutant showed increased susceptibility to erythromycin and roxithromycin. In addition, all three tonB genes were involved in A. hydrophila virulence in zebrafish, and various phenotypes associated with environmental survival were changed with varying degrees in each tonB mutant. TonB2 plays a relatively major role in adhesion, motility, and biofilm formation, while TonB3 is more involved in the anti-phagocytosis of A. hydrophila. In each observed phenotype, no significant difference was found between the single- and double-deletion mutants, whereas the triple-deletion mutant exhibited the most serious defects, indicating that all three TonB systems of A. hydrophila coordinately complement one another. In conclusion, this study elucidates the importance of TonB in iron acquisition and virulence of A. hydrophila, which lays the foundation for future studies regarding the survival mechanisms of this bacterium in iron-restricted environments.

Bacterial peritonitis in a patient with malignant ascites caused by pancreatic carcinoma: Case report and review of literature.

Bacterial peritonitis, an infection of the ascitic fluid, can be classified etiologically as spontaneous or secondary bacterial peritonitis. The former is mainly caused by portal hypertension and its subsequent effects, whereas the latter is caused by the direct dissemination of bacteria into the peritoneal cavity. Previous reports have described some distinguishing features of these two entities. Here, we report the first known case of bacterial peritonitis with Aeromonas hydrophilia and Escherichia coli in a patient with malignant ascites associated with pancreatic carcinoma who exhibited features of both spontaneous and secondary peritonitis. Our report suggests that clinicians should also consider bacterial peritonitis in patients with malignant ascites who present with ostensibly cancer-related symptoms.

Case Report: Bothrops lanceolatus Snakebite Surgical Management-Relevance of Fasciotomy.

Bothrops lanceolatus is an endemic Crotalidae species in Martinique, where approximately 30 cases of envenoming are managed yearly. Envenoming characteristics from Bothrops species include local tissue damage, systemic bleeding, and hemodynamic alterations. We hereby report a case of severe envenomation following B. lanceolatus snakebite to the right calf. Severe local manifestations developed progressively up to the lower limb despite adequate antivenom therapy. Systemic manifestations of venom also occurred, resulting in intensive care therapy. Surgery exploration revealed soft tissue necrosis, friability of the deep fascia, and myonecrosis. The patient needed multiple debridement procedures and fasciotomy of all leg compartments and anterior compartment of the thigh. Diagnosis of necrotizing fasciitis was confirmed by positive Aeromonas hydrophila blood cultures. This clinical case illustrates that major soft tissue infection, including necrotizing fasciitis may occur after snakebite. Abnormal coagulation tests should not delay surgical management, as severe envenoming is a life-threatening condition.

Ceftriaxone-Resistant Aeromonas hydrophila Infection Following Leech Therapy: A New Resistant Strain.

We report a case of ceftriaxone-resistant Aeromonas hydrophila infection in a 32-year-old man after medicinal leech therapy. The patient underwent a free gracilis muscle flap for dorsal foot soft tissue reconstruction. Because of persistent congestion after venous revision, medicinal leech therapy was initiated to aid in flap salvage. Intravenous ceftriaxone was administered prior to application of leeches for prophylaxis against A. hydrophila. Leech therapy was discontinued after 1 week, and ceftriaxone was discontinued 24 hours thereafter. An infection developed despite being on appropriate antibiotics. Culture sensitivities indicated that A. hydrophila was resistant to ceftriaxone.

Trauma Wound Related Infection Caused by Enterobacter cancerogenus and Aeromonas hydrophilia.

We herein describe a case of trauma-related wound infection with a subcutaneous abscess caused by both Enterobacter cancerogenus and Aeromonas hydrophila. An 89-year-old Japanese man was admitted to our hospital because of an injury that he had suffered in a car accident. The right dorsal region of the foot around the wound was reddish and swelling. The pus culture on his right foot grew E. cancerogenus and A. hydrophila. The patient was successfully treated with a 10-day course of meropenem and a 25-day course of levofloxacin. E. cancerogenus can therefore be a causative pathogen in skin and soft tissue infections among trauma patients.

Melaleuca alternifolia essential oil prevents alterations to purinergic enzymes and ameliorates the innate immune response in silver catfish infected with Aeromonas hydrophila.

Aeromonas hydrophila infection represents a major impediment to the development of aquaculture, leading to important economic losses. Over the last few years, different methods have been used to counteract and minimize the negative effects of this infection, such as the use of Melaleuca alternifolia essential oil, popularly known as tea tree oil (TTO), that possess a bactericide action against A. hydrophila. The purinergic system develops an important role in the inflammatory response, principally due to involvement of adenosine triphosphate (ATP) in the inflammatory process, as well as by the anti-inflammatory properties of adenosine (Ado), a molecule that is controlled by NTPDase, 5'-nucleotidase and adenosine deaminase (ADA) enzymes. Thus, the aim of this study was to investigate the involvement of purinergic enzymes in the pathogenesis of A. hydrophila infection, and whether the purinergic pathway and innate immune response are involved in the protective effects of TTO in silver catfish (Rhamdia quelen) experimentally infected with A. hydrophila. Our results revealed that A. hydrophila infection increased seric NTPDase and 5'-nucleotidase activity, while ADA activity decreased. Also, the seric levels of pro-inflammatory cytokines such as interleukin-1 (IL-1), IL-6, tumor necrosis factor alpha (TNF-α) and interferon gamma (INF-γ) increased in the infected fish, while the seric level of anti-inflammatory interleukin-10 (IL-10) decreased. Treatment with TTO was able to prevent the impairment of purinergic enzymes and improve the innate immune response through the modulation of cytokine response during A. hydrophila infection. In summary, prophylactic therapy with TTO can be considered an important approach to improve the immune response and consequently avoid the inflammatory process in fish infected with A. hydrophila.

Aeromonas hydrophila and Campylobacter jejuni isolated in fresh tuna (Thunnus spp) sold in São Paulo, Brazil / Detecção de Aeromonas hydrophila e Campylobacter jejuni em atum (Thunnus spp) fresco comercializado em São Paulo, Brasil

Aeromonas hydrophila and Campylobacter jejuni are bacteria of emerging importance in public health. However, little has been published about fish contaminated by these pathogens. The present study aimed to verify the presence of Aeromonas hydrophila and Campylobacter jejuni in fresh tuna samples (Thunnus spp.) caught off the coast of Santa Catarina State and distributed in the wholesale market of São Paulo/SP. A total of 85 tuna fillet samples were collected and examined by PCR and bacteriological analyses. Aeromonas spp. was detected in 11/85 (13%) samples, with 10/11 (90.9 %) being confirmed as Aeromonas hydrophila by PCR. Campylobacter spp. was found in 10/85 (11.7%) samples, 10/10 (100%) identified as Campylobacter jejuni by PCR and conventional biochemical analyses. Both pathogens were found in 2/85 (2.3%) samples. This is the first report on the contamination of fresh tuna by Campylobacter jejuni and Aeromonas hydrophila in Brazil. In addition to show that tuna can be a vehicle for transmission of pathogens when consumed raw, it emphasizes the importance of further studies to support the control these pathogens in fish...

Aeromonas hydrophila e Campylobacter jejuni são bactérias de importância emergente em saúde pública, porém com escassos trabalhos publicados na área de pescado. O presente estudo investigou a presença de Aeromonas hydrophila e Campylobacter jejuni em amostras de atum (Thunnus spp.) fresco, capturados no litoral de Santa Catarina e distribuídos no comércio atacadista de São Paulo, SP. Foram colhidas 85 amostras de filé de atum e processadas por análises bacteriológicas e PCR. Do total, 11/85 (13%) amostras foram positivas para Aeromonas spp., sendo 10/11 (90,9%) confirmadas como Aeromonas hydrophila pela PCR. Para Campylobacter spp., 10/85 (11,7%) foram positivas, sendo 10/10 (100%) identificadas como Campylobacter jejuni pelas provas bioquímicas tradicionais e PCR ressaltando-se que duas (2/85 - 2,3%) amostras de atum albergavam ambos os patógenos. Trata-se do primeiro relato no Brasil de contaminação de atum fresco por Campylobacter jejuni e Aeromonas hydrophila, indicando que este alimento ingerido in natura pode ser um veículo de transmissão de agentes patogênicos, ressaltando-se a importância de estudos adicionais que deem suporte ao controle desses microrganismos em pescado consumido cru...

Isolamento de Aeromonas hydrophila em Bettas plendens – alterações histopatológicas nas brânquias / Isolation of Aeromonas hydrophila in Bettas plendens - histopathologic changes in gills / Aislamiento de Aeromonas hydrophila en Bettas plendens - alteraciones histopatológicas en las branquias

O objetivo deste estudo foi isolar e caracterizar Aeromonas hydrophila, causadora de mortalidade em peixes descrever as alterações histopatológicas provocadas nas brânquias de machos de beta Bettas plendens. Foram utilizados dez peixes que apresentavam característica de alteração de comportamento como anorexia, letalidade e apatia. Amostras de água, muco e brânquias foram inoculadas em meio de cultura Agar sangue a 25ºC por 48 horas. Foi caracterizado A. hidrófila como principal causa do surto de mortalidade. Foram observadas alterações histopatológicas nas brânquias desde fusão lamelar secundária e necrose do tecido. A. hidrophila prejudica o órgão respiratório de forma irreversível, comprometendo as trocas gasosas levando o peixe ao óbito.

The objective of this study was to isolate and characterize Aeromonas hydrophila, a cause of mortality, and to describe the histopathological changes caused in the gills of Bettas plendens. Ten fish presenting change behavior such as anorexia, lethality and apathy were used in this study. Water, mucus and gill samples were inoculated in blood agar culture medium at 25°C for 48 hours. Aeromonas hidrophila was characterized as the main cause of mortality outbreak. Histopathological changes were observed in the gills, from secondary lamellar fusion to tissue necrosis. A. hidrophila irreversibly harms the respiratory organ, compromising the gaseous exchanges, which leads to the death of the fish.

El objetivo de este estudio fue aislar y caracterizar Aeromonas hydrophila, causante de mortalidad en peces, y describir las alteraciones histopatológicas causadas en las branquias de machos de beta Bettas plendens. Se utilizó 10 peces que presentaban características de cambio de comportamiento como anorexia, mortalidad y apatía. Las muestras de agua, moco y branquias fueron inoculadas en medio de cultivo Agar sangre a 25° C durante 48 horas. Fue caracterizado A. hidrófila como principal causa del surto de mortalidad. Se ha observado cambios histopatológicos en las branquias, desde fusión lamelar secundaria y necrosis de los tejidos. A. hidrophila compromete el órgano respiratorio de forma irreversible, comprometiendo los cambios gaseosos y llevando los peces a la muerte.

Necrotizing soft tissue infection following a peripheral bypass.

BACKGROUND: Necrotizing soft tissue infection (NSTI), formerly referred to as necrotizing fasciitis, is a rare but serious postoperative complication. NSTI following arterial bypass is seen only once in the literature (for a coronary artery bypass) and is not mentioned following peripheral bypass. Although surgical site infections have been studied extensively, there are limited published data on postoperative NSTI and no data for NSTI following peripheral arterial bypass. CASE PRESENTATION: Here we present the first, to our knowledge, reported instance of an NSTI following a lower extremity peripheral bypass. Despite the continued function of the bypass, the patient became rapidly systemically ill with a focus at the surgical site. Because of prompt surgical debridement, the patient survived this severe infection, though did require an above the knee amputation to control the rapid spread of the disease. The patient, a native of American Samoa, was infected with organisms infrequently associated with NSTI, Morganella morganii and Aeromonas hydrophila. This article discusses the diagnosis and treatment of this rare postoperative complication, along with a brief review of the microbiology of the disease. CONCLUSIONS: NSTI is a rare but lethal postoperative complication. To our knowledge, this is the first reported case of an NSTI following an arterial peripheral bypass. This patient survived because of prompt and aggressive intervention.

Dropped head syndrome in a patient with Aeromonas hydrophila-induced septic arthritis of the shoulder.

Septic arthritis of the shoulder is very rarely caused by Aeromonas hydrophila. We present the case of a 45-year-old woman who presented with symptoms of painful shoulder for 2 weeks and dropped head for 1 week prior to admission. A. hydrophila was isolated from a culture of purulent synovial fluid. Magnetic resonance imaging revealed profuse abscess collection between the right infraspinatus muscle and trapezius muscle and swelling of the right and left paraspinatus muscles, which suggested myositis-related dropped head syndrome. After surgery with arthrotomy, function of the shoulder and neck extensors was significantly improved.

Ascophyllum nodosum in the diet of tilapia (Oreochromis niloticus) and its effect after inoculation of Aeromonas hydrophila / Ascophyllum nodosum na dieta de tilapia (Oreochromis niloticus)e o efeito dela depois da inoculação com Aeromonas hydrophila

The objective of this study was to evaluate the effect of Ascophyllum nodosum brown seaweed meal (FAM) on the health of Nile tilapia submitted to inoculation with Aeromonas hydrophila. The experiment was conducted for a period of 40 days using 120 Nile tilapia fingerlings, with age of 40 days, distributed in 20 tanks. A diet including Ascophyllum nodosum seaweed meal at 20g.kg-1 and a control diet (without FAM) were provided which constituted the treatments. Thirty days after beginning the experiment, A. hydrophila was inoculated by bacterial inoculum diluted in sterile saline solution at a concentration of 10(6) CFU ml-1. Except for the width, which was greater for the treatment with the provision of FAM (P<0.05), there was no influence on the performance parameters of the fingerlings, but the occurrence of lesions in animals inoculated with A. hydrophila and fed with FAM was lower and they also exhibited a decline in the lesions in a shorter period of time than the control group. FAM prevents hepatopancreatic congestion in infected animals. Ascophyllum nodosum brown seaweed meal reduced the number of lesions in fish in a shorter time when compared to the control group.

O objetivo desse estudo foi avaliar o efeito da farinha de alga marinha marrom Ascophyllum nodosum (FAM) em alevinois de tilápias do Nilo sob desafio sanitário com inoculação de Aeromonas hydrophila. O experimento foi realizado durante um período de 40 dias com a utilização de 120 alevinos de tilápia do Nilo, distribuídos em 20 aquários. Foi fornecida uma ração com inclusão da farinha da alga marinha Ascophyllum nodosum a 20g.kg ração-1 e uma ração testemunha (sem FAM), que constituiram os tratamentos. Após 30 dias experimentais foi realizada a inoculação de Aeromonas hydrophila por meio de um preparado de inóculo bacteriano com diluição em solução salina estéril a concentração de 106 UFC/ml. Exceto para a largura, que foi maior para o tratamento com o fornecimento da FAM (P<0,05), não houve influência sobre parâmetros de desempenho dos alevinos, mas a ocorrência de lesões nos animais inoculados com A. hydrophila e alimentados com FAM foi menor e, eles também exibiram um declínio das lesões em um menor período de tempo em relação ao grupo controle. FAM impediu a congestão hepatopancreática em animais infectados. A farinha de alga marinha marrom Ascophyllum nodosum reduziu o número de lesões nos peixes em menor tempo quando comparado ao controle.

Skin and soft tissue infections following marine injuries and exposures in travelers.

BACKGROUND: Bacterial skin and soft tissue infections (SSTIs) in travelers often follow insect bites and can present a broad spectrum of clinical manifestations ranging from impetigo to necrotizing cellulitis. Significant SSTIs can also follow marine injuries and exposures in travelers, and the etiologies are often marine bacteria. METHODS: To meet the objectives of describing the pathogen-specific presenting clinical manifestations, diagnostic and treatment strategies, and outcomes of superficial and deep invasive infections in travelers caused by commonly encountered and newly emerging marine bacterial pathogens, Internet search engines were queried with the key words as MESH terms. RESULTS: Travel medicine practitioners should maintain a high index of suspicion regarding potentially catastrophic, invasive bacterial infections, especially Aeromonas hydrophila, Vibrio vulnificus, Chromobacterium violaceum, and Shewanella infections, following marine injuries and exposures. CONCLUSIONS: Travelers with well-known risk factors for the increasing severity of marine infections, including those with open wounds, suppressed immune systems, liver disease, alcoholism, hemochromatosis, hematological disease, diabetes, chronic renal disease, acquired immunodeficiency syndrome, and cancer, should be cautioned about the risks of marine infections through exposures to marine animals, seawater, the preparation of live or freshly killed seafood, and the accidental ingestion of seawater or consumption of raw or undercooked seafood, especially shellfish. With the exception of minor marine wounds demonstrating localized cellulitis or spreading erysipeloid-type reactions, most other marine infections and all Gram-negative and mycobacterial marine infections will require therapy with antibiotic combinations.

Isolamento de Aeromonas hydrophila EM Bettas plendens – alterações histopatológicas nas brânquias / Isolation of Aeromonas hydrophila in Bettas plendens - histopathologic changes in gills / Aislamiento de Aeromonas hydrophila EN Bettas plendens - alteraciones histopatológicas en las branquias

O objetivo deste estudo foi isolar e caracterizar Aeromonas hydrophila, causadora de mortalidade em peixes descrever as alterações histopatológicas provocadas nas brânquias de machos de beta Bettas plendens. Foram utilizados dez peixes que apresentavam característica de alteração de comportamento como anorexia, letalidade e apatia. Amostras de água, muco e brânquias foram inoculadas em meio de cultura Agar sangue a 25ºC por 48 horas. Foi caracterizado A. hidrófila como principal causa do surto de mortalidade. Foram observadas alterações histopatológicas nas brânquias desde fusão lamelar secundária e necrose do tecido. A. hidrophila prejudica o órgão respiratório de forma irreversível, comprometendo as trocas gasosas levando o peixe ao óbito...

The objective of this study was to isolate and characterize Aeromonas hydrophila, a cause of mortality, and to describe the histopathological changes caused in the gills of Bettas plendens. Ten fish presenting change behavior such as anorexia, lethality and apathy were used in this study. Water, mucus and gill samples were inoculated in blood agar culture medium at 25°C for 48 hours. Aeromonas hidrophila was characterized as the main cause of mortality outbreak. Histopathological changes were observed in the gills, from secondary lamellar fusion to tissue necrosis. A. hidrophila irreversibly harms the respiratory organ, compromising the gaseous exchanges, which leads to the death of the fish...

El objetivo de este estudio fue aislar y caracterizar Aeromonas hydrophila, causante de mortalidad en peces, y describir las alteraciones histopatológicas causadas en las branquias de machos de beta Bettas plendens. Se utilizó 10 peces que presentaban características de cambio de comportamiento como anorexia, mortalidad y apatía. Las muestras de agua, moco y branquias fueron inoculadas en medio de cultivo Agar sangre a 25° C durante 48 horas. Fue caracterizado A. hidró- fila como principal causa del surto de mortalidad. Se ha observado cambios histopatológicos en las branquias, desde fusión lamelar secundaria y necrosis de los tejidos. A. hidrophila compromete el órgano respiratorio de forma irreversible, comprometiendo los cambios gaseosos y llevando los peces a la muerte...

Bacteremia due to Aeromonas hydrophila in acute lymphoblastic leukemia.

Aeromonas hydrophila (A. hydrophila) is a low virulent organism but may cause devastating fatal infections in immunocompromised host especially in liver cirrhosis. It is rarely reported to cause septicemia in a patient with Acute Lymphoblastic Leukemia (ALL). The mortality rate of septicemia due to A. hydrophila is 29% to 73%. We report a case of 59-year-old female patient who was a known case of ALL, presented with the complaints of fever, lethargy and generalized weakness for one month. After taking blood samples for investigations, empirical antimicrobial therapy was started. She did not improve after 48 hours of therapy. Meanwhile blood culture revealed pure growth of A. hydrophila. After sensitivity report was available, ciprofloxacin was started. Patient became afebrile after 48 hours of treatment with ciprofloxacin. It is very vital to correctly identified and treat bacteremia due to A. hydrophila especially in the underlying leukemic patient.

Reduction of Aeromonas hidrophyla biofilm on stainless stell surface by essential oils

This study demonstrates the possibility of using sanitizing detergents based on natural products for the elimination and/or reduction of Aeromonas hydrophila biofilm formed on stainless steel surfaces. The goal of this work was to determine the reduction effect of sanitizing detergents containing essential oils of Thymus vulgaris (thyme) and Cymbopogon citratus (lemongrass) on biofilm formed by A. hydrophila on AISI 304 stainless steel coupons, using UHT skimmed milk as substratum. There was adhesion and biofilm formation by A. hydrophila at 28 ºC, presenting 7.60 log cfu.cm-2 after the fourth day of cultivation. There was no significant difference between the lemongrass treatment and that of the thyme oil (p < 0.05). However, both treatments significantly reduced the biofilm, differing significantly from the NaOH control (p > 0.05). The treatment with lemongrass solution reduced the biofilm by 4.51 log cfu cm-2 at 25 ºC. The thyme detergent also reduced the number of cfu cm-2 by 3.84 log cycles at 25 ºC. The use of the lemongrass and thyme solutions efficiently reduced the A. hydrophila biofilm.