Accidental Aluminum Phosphide Intoxication Successfully Treated with Hyperbaric Oxygen Therapy: A Case Report.

The most common pesticide agents are organophosphates and phosphides, aluminum phosphide (ALP) in particular. ALP is a major cause of suicidal poisoning in many countries. In other countries, the problem of accidental, mainly occupational-related, poisoning is also real and actual. Almost two thirds of individuals in poisoning cases have died. This case report describes a case of a patient with accidental ALP intoxication. The origin of the poisoning was the fumigation of stored grain in an agricultural building adjacent to the building in which patient was temporarily housed, while both buildings were connected by an underground corridor, through which the released poison gas penetrated. The case was originally presented by the rescuers as well as healthcare professionals of the local hospital as carbon monoxide intoxication, which has a similar symptomatology as ALP intoxication. The patient was treated comprehensively, including using the HBOT method, which is very unique in the case of phosphine intoxication in human medicine, with an excellent final clinical outcome. This was the first described case of HBOT for ALP intoxication in clinical medicine, although the HBOT indication itself became a coincidence in this case. Further studies must be undertaken to demonstrate the effectiveness of HBOT in treating patients with ALP poisoning.

Effect of hyperbaric oxygen on the growth and susceptibility of facultatively anaerobic bacteria and bacteria with oxidative metabolism to selected antibiotics.

Wild strains of Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were tested in an experimental hyperbaric chamber to determine the possible effect of hyperbaric oxygen on the susceptibility of these strains to the antibiotics ampicillin, ampicillin + sulbactam, cefazolin, cefuroxime, cefoxitin, gentamicin, sulfamethoxazole + trimethoprim, colistin, oxolinic acid, ofloxacin, tetracycline, and aztreonam during their cultivation at 23 °C and 36.5 °C. Ninety-six-well inoculated microplates with tested antibiotics in Mueller-Hinton broth were cultured under standard incubator conditions (normobaric normoxia) for 24 h or in an experimental hyperbaric chamber (HAUX, Germany) for 24 h at 2.8 ATA of 100% oxygen (hyperbaric hyperoxia). The hyperbaric chamber was pressurised with pure oxygen (100%). Both cultures (normoxic and hyperoxic) were carried out at 23 °C and 36.5 °C to study the possible effect of the cultivation temperature. No significant differences were observed between 23 and 36.5 °C cultivation with or without the 2-h lag phase in Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. Cultivation in a hyperbaric chamber at 23 °C and 36.5 °C with or without a 2-h lag phase did not produce significant changes in the minimum inhibitory concentration (MIC) of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. For the tested strains of Pseudomonas aeruginosa, the possible effect of hyperbaric oxygen on their antibiotic sensitivity could not be detected because the growth of these bacteria was completely inhibited by 100% hyperbaric oxygen at 2.8 ATA under all hyperbaric conditions tested at 23 °C and 36.5 °C. Subsequent tests with wild strains of pseudomonads, burkholderias, and stenotrophomonads not only confirmed the fact that these bacteria stop growing under hyperbaric conditions at a pressure of 2.8 ATA of 100% oxygen but also indicated that inhibition of growth of these bacteria under hyperbaric conditions is reversible.

COVID-19 infection prevention and control management during hyperbaric oxygen therapy: a best practice implementation project.

OBJECTIVE: This implementation project compared standard operating procedures, accepted preventive measures, and disinfection procedures between the initial stage of the COVID-19 pandemic (first wave: March 15 to May 31, 2020) and the later stages of the pandemic (second and third waves: September 1, 2020 to January 31, 2021). INTRODUCTION: This project sought to improve compliance with international evidence-based guidelines and clinical standards for the prevention and control of COVID-19 infection during hyperbaric oxygen therapy taking into account the conditions of the local hospital. METHODS: Guided by the JBI evidence implementation framework, seven evidence-based audit criteria were developed for the prevention and control of COVID-19 infection during hyperbaric oxygen therapy. A questionnaire was used to measure compliance in baseline and follow-up audits. RESULTS: Differences between the baseline and follow-up audits were noted for criteria 6 and 7. Criterion 6 increased from 0% to 100% as the hyperbaric facility was equipped with certified ultraviolet-C radiation for air disinfection during the later period, but this equipment was not available in the initial period of the pandemic. Criterion 7 dropped from 100% in the baseline audit to 0% in the follow-up audit because of a significant increase in the operational burden of the treatment capacity of the facility, which made it impossible to comply with the recommended distancing between patients. CONCLUSIONS: Differences were found in preventive measures, disinfection procedures, work organization, and approach to care strategy. The project objectives were met and the implementation strategies proved effective. Larger sample sizes would need be needed to confirm the reproducibility of the results.

Antibiotic resistance and biofilm-forming ability of α-toxin-positive Clostridium septicum isolates worsen patient prognosis.

A total of, 78 Clostridium septicum (CLSE) isolates were screened for genes encoding: α-toxin, flagellin, and resistance to vancomycin (VANg). The isolates were also tested for their ability to form biofilm and their antibiotic susceptibility. All isolates were positive for α-toxin and flagellin genes. However, only 19 isolates (24.3%) showed prevalence for VANg. We observed the strongest capacity to form a biofilm (100%) in isolates from patients with oncologic or septic and febrile diagnoses. This percentage was also very high in patients with colitis and gastrointestinal hemorrhage (72.7%). No less than 43 isolates showed antibiotic resistance, and 21 were multidrug-resistant (MDR). Interestingly, our studies showed a correlation between antibiotic resistance and biofilm formation. A statistically significant difference was observed between biofilm-forming MDR isolates and those with low/no biofilm-forming ability. However, the most impressive observation was the correlation with mortality rate. While the overall mortality rate for CLSE infections was 16.7% (13/78), the mortality rate for patients infected with MDR isolates forming biofilm moderately or strongly reached 38.1% (8/21). This number increased even further when only infections with the biofilm-forming VANg-positive isolates were considered (61.5%; 8/13). Therefore, the ability of a VANg-positive CLSE isolate to form a biofilm has been suggested as a biomarker of poor prognosis.

Detection and molecular characterization of VRE isolates in Slovakia from stool samples positive for Clostridioides difficile toxins.

The study aimed to identify colonized patients as a possible source of eventual VRE (vancomycin-resistant enterococci) infection from stool samples positive for glutamate dehydrogenase antigen, as well as for Clostridioides difficile toxins A and B. The study was carried out from 7/2020 to 9/2021. Stool samples were grown in a brain heart infusion medium with a gram-positive non-spore-forming bacteria supplement under aerobic conditions. The samples for VRE identification were grown on CHROMID® VRE agar, and the MICs for vancomycin and teicoplanin were also estimated. The presence of the vanA/vanB genes was tested using the PCR method. The total number of 113 stool samples positive for Clostridioides difficile toxins was analyzed. Of these samples, 44 isolates with VRE characters were identified. The most prevalent isolates in our set of isolates were Enterococcus faecium (27 isolates, 62%), Enterococcus faecalis (9 isolates, 21%), Enterococcus solitarius (4 isolates, 9%), Enterococcus durans (2 isolates, 4%), 1 isolate Enterococcus sulfurous (2%), and Enterococcus raffinosus (2%). In total, 26 isolates were detected in the study in the presence of vanA genes (24 isolates E. faecium, 2 isolates E. faecalis) and 18 isolates detected in the presence of vanB genes (7 isolates E. faecalis, 4 isolates E. solitarius, 3 isolates E. faecium, 2 isolates E. durans, 1 isolate E. sulfurous, and E. raffinosus). The results of this study showed the local dominance character of the vanA gene of hospital VRE isolates that were carriers of genes associated with high resistance to vancomycin, teicoplanin, and occasionally linezolid.

Hyperbaric oxygen treatment in recurrent development of complex regional pain syndrome: A case report.

A broad spectrum of conditions including neuropathic pain, complex regional pain syndrome (CRPS) and fibromyalgia, have been implicated as causes of chronic pain. There is a need for new and effective treatments that patients can tolerate without significant adverse effects. One potential intervention is hyperbaric oxygen treatment (HBOT). The case reported here is unique in describing repeated HBOT in a patient who developed recurrent post-traumatic CRPS of the lower as well as the upper limbs. In the first event, two months after distortion and abruption of the external right ankle, the patient suffered leg pain, oedema formation, mild hyperaemia, limited mobility of the ankle and CRPS Type 1. In the second event, the same patient suffered fracture-dislocation of the distal radius 1.5 years after the first injury. After the plaster cast was removed the patient developed pain, warmth, colour changes, oedema formation and limited wrist mobility with CRPS Type 1. Pharmacological treatment as well as HBOT were used with significant improvement of functional outcome in both cases. Some studies suggest that patients with a history of CRPS are more likely to develop secondary CRPS compared to the rates reported in the literature among the general population. Patients with a history of CRPS should be counselled that they may be at risk for developing secondary CRPS if they undergo surgery or sustain trauma to another extremity.

Experimental use of flow cytometry to detect bacteria viability after hyperbaric oxygen exposure: Work in progress report.

INTRODUCTION: Hyperbaric oxygen treatment (HBOT), based on inhaling pure oxygen under elevated ambient pressure, is used as adjuvant intervention to promote healing in infected wounds. Despite extensive clinical evidence of beneficial effects of HBOT in soft tissue infections the mechanism of action remains to be elucidated. The aim of this study was to evaluate the use of flow cytometry as a novel method to assess the viability of pathogenic bacteria after hyperbaric oxygen (HBO) exposure. METHODS: Bacterial strains associated with soft tissues infections: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus were exposed to oxygen at 2.8 atmospheres absolute (atm abs) (283.6 kPa) pressure for 45, 90, or 120 min, then stained with propidium iodide and thiazole orange and analysed by flow cytometry. RESULTS: Escherichia coli and Staphylococcus aureus showed no change in viability, nor morphology, the viability of Pseudomonas aeruginosa reduced in a dose-dependent manner and Klebsiella pneumoniae also showed dye uptake after HBO. CONCLUSIONS: These initial results, indicate diverse sensitivity of bacteria to HBO, and suggest that flow cytometry can be used to monitor viability and morphological changes triggered by HBO exposure in bacteria.

The role of intestinal microbiota in the pathogenesis of colorectal carcinoma.

The symbiotic relationship between intestinal microbiota and the host is a major mechanism of prevention against the development of chronic and metabolic diseases. The intestinal microbiota provides several physiological functions of the organism from the creation of a natural functional barrier with a subsequent immunostimulatory activity up to affecting the energy metabolism of the host. Disruption of physiological intestinal microbiota is reported as one of the major etiological factors of initiation and progression of colorectal carcinoma (CRC). Chronic low-grade inflammation is associated with the development of CRC, through the production of inflammatory cytokines and reactive oxygen species. CRC occurs in association with high-protein and high-fat diets in combination with low-fiber intake. The problem of intestinal dysbiosis and oncological diseases is a multidisciplinary problem and it is necessary to focus on several fields of medicine such as public health, clinical pharmacology, and internal medicine. The aim of this review is describing the role of gut dysbiosis in pathogenesis of colorectal carcinoma.

Antibiotic Susceptibility of Cronobacter spp. Isolated from Clinical Samples.

Cronobacter spp. have been recognized as causative agents of various severe infections in pre-term or full-term infants as well as elderly adults suffering from serious underlying disease or malignancy. A surveillance study was designed to identify antibiotic resistance among clinical Cronobacter spp. strains, which were isolated from patients of two hospitals between May 2007 and August 2013. Altogether, 52 Cronobacter spp. isolates were analyzed. Although MALDI-TOF mass spectrometry recognized all Cronobacter sakazakii and Cronobacter malonaticus strains, it could not identify Cronobacter muytjensii strain. Nevertheless, all strains were identified as Cronobacter spp. using multilocus sequence typing (MLST). Strains were tested against 17 types of antibiotics, using the standard microdilution method according to the 2018 European Committee on Antimicrobial Susceptibility Testing criteria. Three Cronobacter species were identified as C. sakazakii (n = 33), C. malonaticus (n = 18), and C. muytjensii (n = 1); all isolates were susceptible to all tested antibiotics. All strains were PCR-negative for bla TEM, bla SHV, and bla CTX-M ß-lactamase genes, as well. Even though the results of this study showed that Cronobacter spp. isolates were pan-susceptible, continued antibiotic resistance surveillance is warranted.Cronobacter spp. have been recognized as causative agents of various severe infections in pre-term or full-term infants as well as elderly adults suffering from serious underlying disease or malignancy. A surveillance study was designed to identify antibiotic resistance among clinical Cronobacter spp. strains, which were isolated from patients of two hospitals between May 2007 and August 2013. Altogether, 52 Cronobacter spp. isolates were analyzed. Although MALDI-TOF mass spectrometry recognized all Cronobacter sakazakii and Cronobacter malonaticus strains, it could not identify Cronobacter muytjensii strain. Nevertheless, all strains were identified as Cronobacter spp. using multilocus sequence typing (MLST). Strains were tested against 17 types of antibiotics, using the standard microdilution method according to the 2018 European Committee on Antimicrobial Susceptibility Testing criteria. Three Cronobacter species were identified as C. sakazakii (n = 33), C. malonaticus (n = 18), and C. muytjensii (n = 1); all isolates were susceptible to all tested antibiotics. All strains were PCR-negative for bla TEM, bla SHV, and bla CTX-M ß-lactamase genes, as well. Even though the results of this study showed that Cronobacter spp. isolates were pan-susceptible, continued antibiotic resistance surveillance is warranted.

Antibiotic susceptibility and production of endotoxin by Ochrobactrum anthropi isolated from environment and from patients with cystic fibrosis.

The aim of this work was to compare production of endotoxin and to determine susceptibility to antibiotics in two groups of specimens-wild-type strains Ochrobactrum anthropi isolated from the environment and the strains isolated from patients with cystic fibrosis. The determination of the endotoxin produced by the test strains was carried on by using a limulus amebocyte lysate test (LAL test). Determination of ATB sensitivity was accomplished by means of a broth dilution method in a microtiter plate (MIC). No significant difference was found between the group of ochrobacters isolated from the environment and the group of ochrobacters isolated from cystic fibrosis patients. Antibiotic sensitivity testing has indicated that the resistance to tigecycline, trimethoprim/sulfamethoxazole, and gentamicin was slightly higher in strains isolated from cystic fibrosis patients in comparison with strains isolated from the environment. In general, most of the test strains were sensitive to most of the antibiotics tested. Significant resistance has been demonstrated for cefotaxime. Resistance was also found for gentamicin in strains number 4 and 7. The MIC was equal to the breakpoint for this antibiotic (8000 mg/L).

Effect of hyperbaric air on endotoxin from Bacteroides fragilis strains.

The aim of the project was to determine any effect of hyperbaric air on Bacteroides fragilis strains cultivated under hyperbaric conditions. Previously, it was hypothesized that there was a correlation between the presence of Bacteroides bacteria in patients preferring a meaty diet and cancer of the small intestine, and particularly of the large intestine and rectum. With respect to the fact that Bacteroides fragilis (BAFR) group are important producers of endotoxins, measurement and statistical evaluation of endotoxin production by individual strains of isolated Bacteroides species were used to compare bacteria isolated from various clinical samples from patients with colon and rectum cancer in comparison with strains isolated from other non-cancer diagnoses. Endotoxin production was proven by quantitative detection using the limulus amebocyte lysate (LAL) test in EU/mL. Production of endotoxins in these bacteria cultured under hyperbaric air conditions was higher than those strains cultured under normobaric anaerobic conditions. But these differences in endotoxin production were not statistically significant (t test with log-transformed data, p value = 0.0910). Based on a two-tier t test for lognormal data, it is possible to cautiously conclude that a statistically significant difference was found between endotoxin production by Bacteroides fragilis strains isolated from non-carcinoma diagnoses (strains (1-6) and strains isolated from colorectal carcinoma diagnoses (strains 7-8; Wilcoxon non-parametric test p = 0.0132; t test = 0.1110; t test with log-transformed data, p value = 0.0294).

Sensitivity to antibiotics of Clostridium difficile toxigenic nosocomial strains.

Clostridium difficile is the etiological agent of diarrhoea and colitis, especially in elderly patients. The incidence of these diseases has increased during the last 10 years. Emergence of so-called hypervirulent strains is considered as one of the main factors responsible for the more severe disease and changed profile of sensitivity to antimicrobial agents. The aim of this work was to determine the sensitivity profile of toxigenic strains of C. difficile in the Czech Republic in 2011-2012 to selected antibiotics. The antibiotics clindamycin, metronidazole, vancomycin and amoxicillin with clavulanic acid were used for this purpose. Isolates cultured on Brazier's C. difficile selective agar were analysed for the presence of toxin genes using Xpert detection system. Xpert analysis revealed that 33 strains carried the genes for toxins tcdB, cdt and tcdCΔ117, thus showing characteristics typical for the hypervirulent ribotype 027/PFGE type NAP1/REA type B1. The remaining 29 strains carried only the gene for toxin B (tcdB) and not cdt and tcdCΔ117. Our results indicate the higher susceptibility of C. difficile hypertoxigenic strains to three out of four tested antibiotics (except vancomycin) than it is for the other toxigenic strains. We found that only 10.34% of other toxigenic strains were resistant to clindamycin, and no resistance was found in all other cases. All the isolates were sensitive to amoxicillin/clavulanic acid in vitro. However, its use is not recommended for therapy of infections caused by C. difficile.

Oxygen tolerance in anaerobic pathogenic bacteria.

A prerequisite for successful identification of anaerobic pathogenic bacteria from samples of clinical material is the method of cultivation. Currently, several methods of cultivation in anaerobic environment are used: cultivation in anaerobic box, anaerobic jar, and in nonrecurring cultivation system. Here, we determined the suitability of the above methods of cultivation using the estimation of the growth (diameters of colony size) of commonly isolated anaerobic pathogens (Bacteroides fragilis, Clostridium difficile, and Clostridium perfringens). The tested bacterial strains were exposed to atmospheric oxygen for various time periods and then they were cultivated using different anaerobic cultivation systems. Maximum growth differed, depending on the type of cultivation and the strain used. Thus, largest zone diameters, in the majority of measurements, were achieved in the anaerobic box. However, nonrecurring cultivation system seemed better in several cases; this applied to the cultivation of C. perfringens after 15, 30, and 60 min exposure to atmospheric oxygen as well as the cultivation of B. fragilis after 30 and 60 min of oxygen exposure. The cultivation in anaerobic box was the most convenient method for growth of C. difficile. In almost all cases, higher growth was observed in nonrecurring cultivation system than in the system of anaerobic jar. On the other hand, no significant differences were observed among these anaerobic cultivation systems which confirmed their applicability (taking into account some individual features concerning the optimization of cultivations) for identification of pathogenic anaerobes.

[Endotoxin production in members of the Bacteroides fragilis group in relation to colorectal cancer humans]. / Produkce endotoxinu u bakterií Bacteroides fragilis group ve vztahu k onemocneni karcinimem tlustého streva a rekta u lidí.

BACKGROUNDS: Members of the Bacteroides fragilis group are the most frequently isolated anaerobic bacteria causing a wide range of severe anaerobic infections. In spite of the high frequency of their occurrence, their presence in clinical specimens is underestimated or even disregarded. The article warns of the severity of these anaerobic pathogens, particularly if detected in clinical samples from the abdominal area. It was hypothesized that there is a correlation between the presence of the bacteria in patients preferring high-meat diet and cancers of the small intestine and especially the colon and rectum [10]. Endotoxins of the bacteria contribute to weakening the patient's immune system damaged by cancer and play a significant role in the progression of small intestine and colon cancer. MATERIAL AND METHODS: Endotoxin production was determined in 140 strains of the Bacteroides fragilis group (B. fragilis, B. thetaiotaomicron, B. distasonis, B. vulgatus) isolated from patients with 7 cancerous and non-cancerous diseases (5 strains of each type of Bacteroides spp. for each diagnosis), using the Pyrosate LAL (limulus amoebocyte lysate) assay. RESULTS: A statistically significant difference in the production of endotoxins isolated from strains of the Bacteroides fragilis group was found between cancerous and non-cancerous diseases. CONCLUSIONS: All four bacterial species produced significantly more endotoxins in cancer than in non-cancerous diseases, with the lowest production in skin abscess (F2,134 = 170, p < 0.0001). Statistically significant differences in the production of endotoxins were also found between the individual members of the Bacteroides fragilis group. B. fragilis and B. vulgatus produced significantly more of (twice as much) endotoxin than B. distasonis and B. thetaiotaomicron (post hoc t-tests, p < 0.00001).

[Culture media for anaerobic bacteria]. / Kultivacní média pro kultivaci anaerobních bakterií.

For culture, isolation and determination of susceptibility of anaerobic pathogens in human microbiology, crucial is the quality of bacteriological culture media for this type of testing. Since anaerobic bacteria are difficult to culture and anaerobic infections are potentially serious, careful attention must be paid to preparation, storing and use of these media. The article provides an overview of numerous solid and liquid culture media used in the diagnosis of anaerobic bacteria.