The antibiotic susceptibility pattern of gas gangrene-forming Clostridium spp. clinical isolates from South-Eastern Hungary.

Introduction:Clostridium perfringens and other gas gangrene-forming clostridia are commensals of the human gut and vaginal microbiota, but can cause serious or even fatal infections. As there are relatively few published studies on antibiotic susceptibility of these bacteria, we decided to perform a 10-year retrospective study in a South-Eastern Hungarian clinical centre.Methods: A total of 372 gas gangrene-forming Clostridium spp. were isolated from clinically relevant samples and identified with rapid ID 32A (bioMérieux, France) and MALDI-TOF MS (Bruker Daltinics, Germany) methods. Antibiotic susceptibility was determined with E-tests.Results: We identified 313 C. perfringens, 20 C. septicum, 10 C. sordellii, 10 C. sporogenes, 9 C. tertium, 6 C. bifermentans, 4 C. histolyticum isolates. In C. perfringens isolates, the rate of penicillin resistance was 2.6% and the rate of clindamycin resistance 3.8%. Penicillin resistance was found in 6.8% and clindamycin resistance in 8.5% of the non-perfringens Clostridium spp. isolates.Conclusion: The antibiotic susceptibility of C. perfringens isolates was in good agreement with previous publications. The rates of resistance to penicillin and clindamycin were very low. The resistance rates of non-perfringens Clostridium spp. isolates were higher than those of C. perfringens strains, but lower than those published in the literature.

Brain abscess and cervical lymphadenitis due to Paraclostridium bifermentans: A report of two cases.

Paraclostridium bifermentans (current nomenclature of Clostridium bifermentans since 2016) is a gram-positive, spore-forming anaerobic bacterium. Here, we describe two cases associated with this organism. The first, primarily a case of tubercular brain abscess where P. bifermentans was isolated as part of a polymicrobial flora, following a neurosurgical procedure for the same and the second, a case of cervical lymphadenitis from which it was isolated as the sole causative agent. There are only a few reported cases of P. bifermentans in literature and these cases illustrate the widening spectrum of infections related to it.

Evaluating new bio-hydrogen producers: Clostridium perfringens strain JJC, Clostridium bifermentans strain WYM and Clostridium sp. strain Ade.TY.

Three newly discovered H2 producing bacteria namely Clostridium perfringens strain JJC, Clostridium bifermentans strain WYM and Clostridium sp. strain Ade.TY originated from landfill leachate sludge have demonstrated highly efficient H2 production. The maximum H2 production attained from these isolates are in the descending order of strain C. perfringens strain JJC > C. bifermentans strain WYM > Clostridium sp. strain Ade.TY with yield of 4.68 ± 0.12, 3.29 ± 0.11, and 2.87 ± 0.10 mol H2/mol glucose, respectively. The result has broken the conventional theoretical yield of 4 mol H2/mol glucose. These isolates were thermodynamically favourable with Gibbs free energy between -33 and -35 kJ/mol (under process conditions: pH 6, 37 °C and 5 g/L glucose). All three isolates favour butyrate pathway for H2 production with the ratio of acetate and butyrate of 0.77, 0.65 and 0.80 for strain JJC, WYM and Ade.TY, respectively. This study reported provides a new insight on the potential of unique bacteria in H2 production.

Isolation process of industrially useful Clostridium bifermentans from natural samples.

A selective isolation procedure of clostridial strains from natural samples able to convert glycerol to 1,3-propanediol (1,3-PD) and organic acids was investigated. The modified PY medium of high concentration of NaHCO(3) was shown to be highly selective for Clostridium bifermentans. Obtained isolates produced mainly 1,3-PD, lactic, acetic, and formic acids from glycerol.

GAC adsorption filters as barriers for viruses, bacteria and protozoan (oo)cysts in water treatment.

Granular Activated Carbon (GAC) adsorption filtration is commonly used in drinking water treatment to remove NOM and micro-pollutants and on base of the process conditions a certain capacity to eliminate pathogenic micro-organisms was expected. The experiences with the mandatory quantitative microbial risk assessment of Dutch drinking water revealed a lack of knowledge on the elimination capacity of this process for pathogens. The objective of the current study was to determine the capacity of GAC filtration to remove MS2, Escherichia coli and spores of Clostridium bifermentans as process indicators for pathogens and more directly of (oo)cysts of Cryptosporidium parvum and Giardia lamblia. Challenge tests with fresh and loaded GAC were performed in pilot plant GAC filters supplied with pre-treated surface water at a contact time which was half of the contact time of the full-scale GAC filters. MS2 phages were not removed and the removal of E. coli and the anaerobic spores was limited ranging from < or =0.1-1.1 log. The (oo)cysts of C. parvum and G. lamblia, however, were removed significantly (1.3-2.7 log). On base of the results of the experiments and the filtration conditions the removal of the indicator bacteria and (oo)cysts was largely attributed to attachment. The model of the Colloid Filtration Theory was used to describe the removal of the dosed biocolloids in the GAC filters, but the results demonstrated that there is a lack of quantitative knowledge about the influence of collector characteristics on the two major CFT parameters, the single collector and the sticking efficiency.

Resolution of culture Clostridium bifermentans DPH-1 into two populations, a Clostridium sp. and tetrachloroethene-dechlorinating Desulfitobacterium hafniense strain JH1.

Clostridium bifermentans strain DPH-1 reportedly dechlorinates tetrachloroethene (PCE) to cis-1,2-dichloroethene. Cultivation-based approaches resolved the DPH-1 culture into two populations: a nondechlorinating Clostridium sp. and PCE-dechlorinating Desulfitobacterium hafniense strain JH1. Strain JH1 carries pceA, encoding a PCE reductive dehalogenase, and shares other characteristics with Desulfitobacterium hafniense strain Y51.

Recovery of anaerobic bacteria from wounds after lawn-mower injuries.

Accidental injury while using lawn mowers can cause serious infectious complications in the injured extremity. Anaerobic bacteria were rarely recovered from this infection. Two children who sustained injury in their foot by a lawn mower developed severe wound infection. Culture of the wound from 1 patient had heavy growth of Clostridium bifermentans and Peptostreptococcus magnus, and the culture from the other child grew Clostridium perfringens. Antimicrobial therapy directed at the pathogens and vigorous surgical irrigation and debridement led to complete recovery from the infection. This report illustrates the recovery of anaerobic bacteria from children that had wound infection after lawn-mower injury.