High-definition optical coherence tomography (HD-OCT) permits real-time 3-D imaging of the impact... more High-definition optical coherence tomography (HD-OCT) permits real-time 3-D imaging of the impact of selected agents on human skin allografts. The real-time 3-D HD-OCT assessment of i) the impact on morphological and cellular characteristics of the processing of human acellular dermal matrices (HADMs) and ii) repopulation of HADMs in vitro by human fibroblasts and remodelling of the extracellular matrix by these cells. Four different skin decellularisation methods, Dispase II/Triton X-100, Dispase II/SDS (sodium dodecyl sulphate), NaCl/Triton X-100 and NaCl/SDS, were analyzed by HD-OCT. HD-OCT features of epidermal removal, dermo-epidermal junction (DEJ) integrity, cellularity and dermal architecture were correlated with reflectance confocal microscopy (RCM), histopathology and immunohistochemistry. Human adult dermal fibroblasts were in vitro seeded on the NaCl/Triton X-100 processed HADMs, cultured up to 19 days and evaluated by HD-OCT in comparison with MTT proliferation test and histology. Epidermis was effectively removed by all treatments. DEJ was best preserved after NaCl/Triton X-100 treatment. Dispase II/SDS treatment seemed to remove all cellular debris in comparison with NaCl/Triton X-100 but disturbed the DEJ severely. The dermal micro-architectural structure and vascular spaces of (sub)papillary dermis were best preserved with the NaCl/Triton X-100. The impact on the 3-D structure and vascular holes was detrimental with Dispase II/SDS. Elastic fibre fragmentation was only observed after Dispase II incubation. HD-OCT showed that NaCl/Triton X-100 processed matrices permitted in vitro repopulation by human dermal fibroblasts (confirmed by MTT test and histology) and underwent remodelling upon increasing incubation time. Care must be taken in choosing the appropriate processing steps to maintain selected properties of the extracellular matrix in HADMs. Processing HADMs with NaCl/Triton X-100 permits in vitro the proliferation and remodelling activity of human dermal fibroblasts. HD-OCT provides unique real-time and non-invasive 3-D imaging of tissue-engineered skin constructs and complementary morphological and cytological information. This article is protected by copyright. All rights reserved.
Burkholderia multivorans is a member of the Burkholderia cepacia complex (Bcc), notorious for its... more Burkholderia multivorans is a member of the Burkholderia cepacia complex (Bcc), notorious for its pathogenicity in persons with cystic fibrosis. Epidemiological surveillance suggests that patients predominantly acquire B. multivorans from environmental sources, with rare cases of patient-to-patient transmission. Here we report on the genomic analysis of thirteen isolates from an endemic B. multivorans strain infecting four cystic fibrosis patients treated in different pediatric cystic fibrosis centers in Belgium, with no evidence of cross-infection. All isolates share an identical sequence type (ST-742) but whole genome analysis shows that they exhibit peculiar patterns of genomic diversity between patients. By combining short and long reads sequencing technologies, we highlight key differences in terms of small nucleotide polymorphisms indicative of low rates of adaptive evolution within patient, and well-defined, hundred kbps-long segments of high enrichment in mutations between p...
International Journal of Infectious Diseases, 2018
Background: We are currently witnessing the global emergence of multi-drug resistant (MDR) Gram-n... more Background: We are currently witnessing the global emergence of multi-drug resistant (MDR) Gram-negative rods (GNR) in neutropenic patients with oncohematologic diseases. The aim of this study was to analyze the episodes of bacteremia caused by MDR-GNR in febrile neutropenic patients (FNP). Methods & Materials: We prospectively enrolled Gram negative rods bacteriemia occurring in admitted FNP from 01/01/2008-10/31/2017. Clinical and microbiological data were collected. MDR-GNR were defined as resistant to at least three classes of antibiotics: aminoglycosides, third-and fourth-generation cephalosporins, quinolones, carbapenems and/or betalactams with beta-lactamase inhibitors. MDR P. aeruginosa was defined as resistant to at least piperacillin, ciprofloxacin, ceftazidime and carbapenems. Univariate analysis was performed, considering statistically significant a p-value ≤0.05. Results: Throughout the study period, 635 episodes of febrile neutropenia were registered. Bacteriemia occurred in 57% (362/635) of episodes (in 194 patients). The median age of patients with bacteriemia was 40.9 years with a male predominance (56.6%). Associated disease: acute myeloid leukemia 47%, acute lymphoid leukemia 29%, other 24%. Disease in induction phase: 35.1%; consolidation: 21%; relapsed 17.1%. Median time from hospital admission to the development of bacteremia: 16 days. Previous antibiotic treatment: 54.8%. Quinolone prophylaxis was performed in 33.4% (applied from the start of the study to May 2010). GNR were isolated in 240 of 397 pathogens(60.45%) corresponding 53.75% (129/240) to MDR-GNR. Bacteriemia developing after 48 hours of admission was caused by MDR-GNR in 90.7% of cases. Mechanisms of resistance: ESBLs 53/129(41%), AMPc 8/129(6.2%), OXA beta-lactamases 8/129(8%), MBL carbapenemases 3/129(2.3%), KPC carbapenemases 6/129(4.6%), other 51/129(39.6%). Breakthrough bacteremia was caused by MDR-GNR in 69/362 cases (19%). Empirical treatment (ET) was inappropriate in 50/240 GNR isolates, 41 were MDR-GNR. Lethality was 19.9% (72/362) among episodes of bacteriemia. Univariate analysis: bacteriemia after 48 hours of admission(p < 0.001), breakthrough bacteremia(p < 0.001) and inappropriate ET(p < 0.001) were significantly associated to MDR-GNR bacteremia. Conclusion: The majority of bacteremia was due to MDR-GNR and the presentation was predominantly late. The isolation of MDR-GNR was significantly associated to bacteremia after 48 hours admission, breakthrough bacteriemia and inappropriate ET. MDR-GNR coverage should be considered when choosing an ET.
S23 systemic inflammatory response and oxidative stress. Productions of reactive oxygen species a... more S23 systemic inflammatory response and oxidative stress. Productions of reactive oxygen species and cytokines play important roles in scald-induced multiple organ failure. Prevention of multiple organ failure has been proposed by reducing oxidative stress after scald injury. Methods: Crassulaceae Rhodiola, a traditional Chinese medicine, is known as a potent antioxidant. The purpose of present study is observed whether Rhodiola extracts can protect against scald-induced oxidative and inflammatory injury. Under brief anesthesia, dorsum of the rats was shaved, exposed to 90' water bath for 10 or 15 seconds, which resulted in partial-thickness second-degree skin burn involving 30% of the total body surface area. These rats were subjected to vesicle or Rhodiola extracts treatment twice daily for 2 days. Results: Significant elevated levels of oxygen radical absorbance capacity (ORAC), lipid peroxidation (malondialdehyde; MDA), TNF-alpha, and IL-1 beta in plasma and skin tissue in the scald induced rats (vesicle) compared to control (sham) group. However, all of these markers of injury were significantly reduced in Rhodiola extracts treatment rats. Protection of Rhodiola extracts treatment was further demonstrated by Histopathologic examination in the dermal revealed with H and E staining. Conclusion: Rhodiola extracts treatment can used as an effective approach to protect against scald-induced oxidative and inflammatory skin injury.
and Madaba for the ages 2-3 years and 3-4 years was as follows: Penicillin (90.9%; 81.3%) for Irb... more and Madaba for the ages 2-3 years and 3-4 years was as follows: Penicillin (90.9%; 81.3%) for Irbid, and (91.1%; 89.7%) for Madaba; clarithromycin (72.7%; 81.3%) for Irbid and (64.4%, 75.9%) for Madaba; trimethoprim-sulfamethoxazole (100%; 100%) for Irbid and (100%, 93.1%) for Madaba. Multiresistance in Irbid and Madaba was 78.9% and 68.9% respectively. 81 isolates were macrolide resistant in both cities, where 48.3% and 51.7% were M-phenotype and cMLS B for Irbid and 42.3% and 55.8% for Madaba, respectively. Predominant serotypes were 19F (18.8%) and 23F (11.6%) in both cities. Conclusion: There was high carriage of pneumococci in both cities. The resistance has reached an alarming rate for penicillin and trimethoprim-sulfamethoxazole in both cities. Localizing specific serotypes among specific areas is recommended for better control with the available PCVs.
The sequence of oprI, the gene coding for the major outer membrane lipoprotein I, was determined ... more The sequence of oprI, the gene coding for the major outer membrane lipoprotein I, was determined by PCR sequencing for representatives of 17 species of rRNA group I pseudomonads, with a special emphasis on Pseudomonas aeruginosa and Pseudomonas fluorescens. Within the P. aeruginosa species, oprI sequences for 25 independent isolates were found to be identical, except for one silent substitution at position 96. The oprI sequences diverged more for the other rRNA group I pseudomonads (85 to 91% similarity with P. aeruginosa oprI). An accumulation of silent and also (but to a much lesser extent) nonsilent substitutions in the different sequences was found. A clustering according to the respective presence and/or positions of the HaeIII, PvuII, and SphI sites could also be obtained. A sequence cluster analysis showed a rather widespread distribution of P. fluorescens isolates. All other rRNA group I pseudomonads clustered in a manner that was in agreement with other studies, showing that the oprI gene can be useful as a complementary phylogenetic marker for classification of rRNA group I pseudomonads.
The emergence of antibiotic-resistant bacteria and decrease in the discovery rate of novel antibi... more The emergence of antibiotic-resistant bacteria and decrease in the discovery rate of novel antibiotics takes mankind back to the ‘pre-antibiotic era' and search for alternative treatments. Bacteriophages have been one of promising alternative agents which can be utilised for medicinal and biological control purposes in agriculture and related fields. The idea to treat bacterial infections with phages came out of the pioneering work of Félix d‘Hérelle but this was overshadowed by the success of antibiotics. Recent renewed interest in phage therapy is dictated by its advantages most importantly by their specificity against the bacterial targets. This prevents complications such as antibiotic-induced dysbiosis and secondary infections. This article is compiled by the participants of the Expert Round Table conference ‘Bacteriophages as tools for therapy, prophylaxis and diagnostics' (19–21 October 2015) at the Eliava Institute of Bacteriophage, Microbiology and Virology, Tbilisi...
International Journal of Infectious Diseases, 2014
Background: Antibiotic resistance (ABR), a typical emerging phenomenon of highly complex and self... more Background: Antibiotic resistance (ABR), a typical emerging phenomenon of highly complex and self-organising systems evolving at the edge of chaos, is a worldwide problem. Beside over consumption and inappropriate use several fundamental issues are still not well understood, like their natural role, while data on incidence and prevalence of antibiotic resistances among animals, domesticated and wild are also only fragmentary available. Methods & Materials: Our batch (86) included pseudomonad isolates, mainly aeruginosa, (of 50 pets (dog, cat, turtle, parrot), 16 farm animals (cow, sheep, horse, pig, goat), 7 zoo animals (seal, dolphin, kangaroo, tamarind) and 13 wild sea turtles. The strains were biochemically (Vitek-BioMérieux) and genomically identified (pseudomonad-specific oprI/L lipoprotein PCR) before antibiotic resistance profiling and P.aeruginosa serotyping was done. Antibiotics tested were temocillin, ticarcillin, ticarcillin + clavulanic acid, piperacillin/tazobactam, ceftazidime, cefepim, aztreonam, imipenem, meropenem, amykacin, gentamycin, tobramycin, ciprofloxacin, tigecyclin, fosfomycin, colistin, and timethoprim + sulfamethoxazole. All strains were genotyped by Rep-PCR (Diversilab-BioMérieux). All isolates originated from Portugal except the turtle isolates who were sampled in Sao Tomé.
International Journal of Infectious Diseases, 2014
Background: One of the greatest threat to the recent generation of antibiotics is the increasing ... more Background: One of the greatest threat to the recent generation of antibiotics is the increasing prevalence of bacterial resistant, specially Gram-negative bacteria. Acinetobacter baumanni is one of the most important superbugs becoming increasingly prevalent in patients with diabetes mellitus in Middle East particularly in Saudi Arabia. We have shown that diabetic patients are more susceptible to acquire infection with these type of superbugs A.baumannii than the rest of the population. Carbapenem resistance in A.baumannii limits therapeutic options and is largely manifested by -lactamases and metallo--lactamase that play a significant role in mechanisms of drug-resistance in diabetic patients. The aim is to investigate the level of threat of these pathogens to diabetics and the mechanisms of drug-resistance of patients in Saudi Arabia hospitals. Methods & Materials: A total of 64 non-repetitive, strains collected between 2008 to 2012 from different specimens from diabetic patients from King Faisal Specialist Hospital and Research Centre, Riyadh. All isolates were identified by Vitek system. Multiplex PCR using primers for bla OXA-51 combined with primers for bla OXA-23 , bla OXA-24/40 and bla OXA-58 was employed. PCR was used for detection of -lactamase and metallo--lactamase genes and insertion sequences IS elements. Pulsed-field gel electrophoresis (PFGE) has been performed. MICs was determined by dilution method. Results: Sixty-four clinical isolates of A. baumannii having bla OXA-51-like gene. All isolates were resistant to imipenem and meropenem (MIC > 16-32 mg/L) except four were intermediate (MIC = 8 mg/L) and Six were susceptible (MIC 0.5-2 mg/L) to both of them. All isolates were sensitive to tigecycline and colistin (MIC 0.5-2 mg/L) except four were resistant (MIC 8-32 mg/L) and three were intermediate to tigecycline only (MIC 4-8). The cause of resistance was from -lactamase of bla OXA-23 and bla OXA-24/40 and metallo--lactamase bla VIM and bla SPM. Fifty-nine isolates were possess the insertion sequence ISAba1. PFGE showed Nine clusters of bla OXA-51-like enzymes. Conclusion: Carbapenem-resistant Acinetobacter baumannii is a serious superbugs threaten diabetic patients due to the circulation of -lactamases and metallo--lactamase in Saudi Arabian hospitals. Furthermore, the emergence of tigecycline plus colistin resistance is causing a treatment shortfall for these patients.
Objectives: To rapidly detect transmission of Pseudomonas aeruginosa (P. aeruginosa) among cystic... more Objectives: To rapidly detect transmission of Pseudomonas aeruginosa (P. aeruginosa) among cystic fibrosis (CF) patients in a hospital environment, so that the necessary measures can be taken to avoid future transmissions. Methods: The use of molecular typing techniques such as rep-PCR (Diversilab ® , bioMérieux), in combination with multiplex PCR targeting ferripyoverdine receptor genes and S-type pyocin genes to distinguish between P. aeruginosa isolates. Conclusion: In order to quickly detect and respond to bacterial transmissions and outbreaks in hospitals, an appropriate detection method to identify these transmission events and strains is indispensable. Although the use of rep-PCR to determine the clonally relatedness of potential transmissible strains is very useful, we have shown that a combination of the latter technique together with a specific multiplex PCR targeting virulence factors such as ferripyoverdine receptors and pyocins allows for the accurate detection of transmission of P. aeruginosa among CF patients in a hospital environment. We showed that intra CF patient P. aeruginosa transmission can occur but that there is not really one highly transmissible CF clone spreading.
Cultures of human epithelial cells (keratinocytes) are used as an additional surgical tool to tre... more Cultures of human epithelial cells (keratinocytes) are used as an additional surgical tool to treat critically burnt patients. Initially, the production environment of keratinocyte grafts was regulated exclusively by national regulations. In 2004, the European Tissues and Cells Directive 2004/23/EC (transposed into Belgian Law) imposed requirements that resulted in increased production costs and no significant increase in quality and/or safety. In 2007, Europe published Regulation (EC) No 1394/2007 on Advanced Therapy Medicinal Products. Overnight, cultured keratinocytes became (arguably) "Advanced" Therapy Medicinal Products (ATMPs) to be produced as human medicinal products. The practical impact of these amendments was (and still is) considerable. A similar development appears imminent in bacteriophage therapy. Bacteriophages are bacterial viruses that can be used for tackling the problem of bacterial resistance development to antibiotics. Therapeutic natural bacteriopha...
High-definition optical coherence tomography (HD-OCT) permits real-time 3-D imaging of the impact... more High-definition optical coherence tomography (HD-OCT) permits real-time 3-D imaging of the impact of selected agents on human skin allografts. The real-time 3-D HD-OCT assessment of i) the impact on morphological and cellular characteristics of the processing of human acellular dermal matrices (HADMs) and ii) repopulation of HADMs in vitro by human fibroblasts and remodelling of the extracellular matrix by these cells. Four different skin decellularisation methods, Dispase II/Triton X-100, Dispase II/SDS (sodium dodecyl sulphate), NaCl/Triton X-100 and NaCl/SDS, were analyzed by HD-OCT. HD-OCT features of epidermal removal, dermo-epidermal junction (DEJ) integrity, cellularity and dermal architecture were correlated with reflectance confocal microscopy (RCM), histopathology and immunohistochemistry. Human adult dermal fibroblasts were in vitro seeded on the NaCl/Triton X-100 processed HADMs, cultured up to 19 days and evaluated by HD-OCT in comparison with MTT proliferation test and histology. Epidermis was effectively removed by all treatments. DEJ was best preserved after NaCl/Triton X-100 treatment. Dispase II/SDS treatment seemed to remove all cellular debris in comparison with NaCl/Triton X-100 but disturbed the DEJ severely. The dermal micro-architectural structure and vascular spaces of (sub)papillary dermis were best preserved with the NaCl/Triton X-100. The impact on the 3-D structure and vascular holes was detrimental with Dispase II/SDS. Elastic fibre fragmentation was only observed after Dispase II incubation. HD-OCT showed that NaCl/Triton X-100 processed matrices permitted in vitro repopulation by human dermal fibroblasts (confirmed by MTT test and histology) and underwent remodelling upon increasing incubation time. Care must be taken in choosing the appropriate processing steps to maintain selected properties of the extracellular matrix in HADMs. Processing HADMs with NaCl/Triton X-100 permits in vitro the proliferation and remodelling activity of human dermal fibroblasts. HD-OCT provides unique real-time and non-invasive 3-D imaging of tissue-engineered skin constructs and complementary morphological and cytological information. This article is protected by copyright. All rights reserved.
Burkholderia multivorans is a member of the Burkholderia cepacia complex (Bcc), notorious for its... more Burkholderia multivorans is a member of the Burkholderia cepacia complex (Bcc), notorious for its pathogenicity in persons with cystic fibrosis. Epidemiological surveillance suggests that patients predominantly acquire B. multivorans from environmental sources, with rare cases of patient-to-patient transmission. Here we report on the genomic analysis of thirteen isolates from an endemic B. multivorans strain infecting four cystic fibrosis patients treated in different pediatric cystic fibrosis centers in Belgium, with no evidence of cross-infection. All isolates share an identical sequence type (ST-742) but whole genome analysis shows that they exhibit peculiar patterns of genomic diversity between patients. By combining short and long reads sequencing technologies, we highlight key differences in terms of small nucleotide polymorphisms indicative of low rates of adaptive evolution within patient, and well-defined, hundred kbps-long segments of high enrichment in mutations between p...
International Journal of Infectious Diseases, 2018
Background: We are currently witnessing the global emergence of multi-drug resistant (MDR) Gram-n... more Background: We are currently witnessing the global emergence of multi-drug resistant (MDR) Gram-negative rods (GNR) in neutropenic patients with oncohematologic diseases. The aim of this study was to analyze the episodes of bacteremia caused by MDR-GNR in febrile neutropenic patients (FNP). Methods & Materials: We prospectively enrolled Gram negative rods bacteriemia occurring in admitted FNP from 01/01/2008-10/31/2017. Clinical and microbiological data were collected. MDR-GNR were defined as resistant to at least three classes of antibiotics: aminoglycosides, third-and fourth-generation cephalosporins, quinolones, carbapenems and/or betalactams with beta-lactamase inhibitors. MDR P. aeruginosa was defined as resistant to at least piperacillin, ciprofloxacin, ceftazidime and carbapenems. Univariate analysis was performed, considering statistically significant a p-value ≤0.05. Results: Throughout the study period, 635 episodes of febrile neutropenia were registered. Bacteriemia occurred in 57% (362/635) of episodes (in 194 patients). The median age of patients with bacteriemia was 40.9 years with a male predominance (56.6%). Associated disease: acute myeloid leukemia 47%, acute lymphoid leukemia 29%, other 24%. Disease in induction phase: 35.1%; consolidation: 21%; relapsed 17.1%. Median time from hospital admission to the development of bacteremia: 16 days. Previous antibiotic treatment: 54.8%. Quinolone prophylaxis was performed in 33.4% (applied from the start of the study to May 2010). GNR were isolated in 240 of 397 pathogens(60.45%) corresponding 53.75% (129/240) to MDR-GNR. Bacteriemia developing after 48 hours of admission was caused by MDR-GNR in 90.7% of cases. Mechanisms of resistance: ESBLs 53/129(41%), AMPc 8/129(6.2%), OXA beta-lactamases 8/129(8%), MBL carbapenemases 3/129(2.3%), KPC carbapenemases 6/129(4.6%), other 51/129(39.6%). Breakthrough bacteremia was caused by MDR-GNR in 69/362 cases (19%). Empirical treatment (ET) was inappropriate in 50/240 GNR isolates, 41 were MDR-GNR. Lethality was 19.9% (72/362) among episodes of bacteriemia. Univariate analysis: bacteriemia after 48 hours of admission(p < 0.001), breakthrough bacteremia(p < 0.001) and inappropriate ET(p < 0.001) were significantly associated to MDR-GNR bacteremia. Conclusion: The majority of bacteremia was due to MDR-GNR and the presentation was predominantly late. The isolation of MDR-GNR was significantly associated to bacteremia after 48 hours admission, breakthrough bacteriemia and inappropriate ET. MDR-GNR coverage should be considered when choosing an ET.
S23 systemic inflammatory response and oxidative stress. Productions of reactive oxygen species a... more S23 systemic inflammatory response and oxidative stress. Productions of reactive oxygen species and cytokines play important roles in scald-induced multiple organ failure. Prevention of multiple organ failure has been proposed by reducing oxidative stress after scald injury. Methods: Crassulaceae Rhodiola, a traditional Chinese medicine, is known as a potent antioxidant. The purpose of present study is observed whether Rhodiola extracts can protect against scald-induced oxidative and inflammatory injury. Under brief anesthesia, dorsum of the rats was shaved, exposed to 90' water bath for 10 or 15 seconds, which resulted in partial-thickness second-degree skin burn involving 30% of the total body surface area. These rats were subjected to vesicle or Rhodiola extracts treatment twice daily for 2 days. Results: Significant elevated levels of oxygen radical absorbance capacity (ORAC), lipid peroxidation (malondialdehyde; MDA), TNF-alpha, and IL-1 beta in plasma and skin tissue in the scald induced rats (vesicle) compared to control (sham) group. However, all of these markers of injury were significantly reduced in Rhodiola extracts treatment rats. Protection of Rhodiola extracts treatment was further demonstrated by Histopathologic examination in the dermal revealed with H and E staining. Conclusion: Rhodiola extracts treatment can used as an effective approach to protect against scald-induced oxidative and inflammatory skin injury.
and Madaba for the ages 2-3 years and 3-4 years was as follows: Penicillin (90.9%; 81.3%) for Irb... more and Madaba for the ages 2-3 years and 3-4 years was as follows: Penicillin (90.9%; 81.3%) for Irbid, and (91.1%; 89.7%) for Madaba; clarithromycin (72.7%; 81.3%) for Irbid and (64.4%, 75.9%) for Madaba; trimethoprim-sulfamethoxazole (100%; 100%) for Irbid and (100%, 93.1%) for Madaba. Multiresistance in Irbid and Madaba was 78.9% and 68.9% respectively. 81 isolates were macrolide resistant in both cities, where 48.3% and 51.7% were M-phenotype and cMLS B for Irbid and 42.3% and 55.8% for Madaba, respectively. Predominant serotypes were 19F (18.8%) and 23F (11.6%) in both cities. Conclusion: There was high carriage of pneumococci in both cities. The resistance has reached an alarming rate for penicillin and trimethoprim-sulfamethoxazole in both cities. Localizing specific serotypes among specific areas is recommended for better control with the available PCVs.
The sequence of oprI, the gene coding for the major outer membrane lipoprotein I, was determined ... more The sequence of oprI, the gene coding for the major outer membrane lipoprotein I, was determined by PCR sequencing for representatives of 17 species of rRNA group I pseudomonads, with a special emphasis on Pseudomonas aeruginosa and Pseudomonas fluorescens. Within the P. aeruginosa species, oprI sequences for 25 independent isolates were found to be identical, except for one silent substitution at position 96. The oprI sequences diverged more for the other rRNA group I pseudomonads (85 to 91% similarity with P. aeruginosa oprI). An accumulation of silent and also (but to a much lesser extent) nonsilent substitutions in the different sequences was found. A clustering according to the respective presence and/or positions of the HaeIII, PvuII, and SphI sites could also be obtained. A sequence cluster analysis showed a rather widespread distribution of P. fluorescens isolates. All other rRNA group I pseudomonads clustered in a manner that was in agreement with other studies, showing that the oprI gene can be useful as a complementary phylogenetic marker for classification of rRNA group I pseudomonads.
The emergence of antibiotic-resistant bacteria and decrease in the discovery rate of novel antibi... more The emergence of antibiotic-resistant bacteria and decrease in the discovery rate of novel antibiotics takes mankind back to the ‘pre-antibiotic era' and search for alternative treatments. Bacteriophages have been one of promising alternative agents which can be utilised for medicinal and biological control purposes in agriculture and related fields. The idea to treat bacterial infections with phages came out of the pioneering work of Félix d‘Hérelle but this was overshadowed by the success of antibiotics. Recent renewed interest in phage therapy is dictated by its advantages most importantly by their specificity against the bacterial targets. This prevents complications such as antibiotic-induced dysbiosis and secondary infections. This article is compiled by the participants of the Expert Round Table conference ‘Bacteriophages as tools for therapy, prophylaxis and diagnostics' (19–21 October 2015) at the Eliava Institute of Bacteriophage, Microbiology and Virology, Tbilisi...
International Journal of Infectious Diseases, 2014
Background: Antibiotic resistance (ABR), a typical emerging phenomenon of highly complex and self... more Background: Antibiotic resistance (ABR), a typical emerging phenomenon of highly complex and self-organising systems evolving at the edge of chaos, is a worldwide problem. Beside over consumption and inappropriate use several fundamental issues are still not well understood, like their natural role, while data on incidence and prevalence of antibiotic resistances among animals, domesticated and wild are also only fragmentary available. Methods & Materials: Our batch (86) included pseudomonad isolates, mainly aeruginosa, (of 50 pets (dog, cat, turtle, parrot), 16 farm animals (cow, sheep, horse, pig, goat), 7 zoo animals (seal, dolphin, kangaroo, tamarind) and 13 wild sea turtles. The strains were biochemically (Vitek-BioMérieux) and genomically identified (pseudomonad-specific oprI/L lipoprotein PCR) before antibiotic resistance profiling and P.aeruginosa serotyping was done. Antibiotics tested were temocillin, ticarcillin, ticarcillin + clavulanic acid, piperacillin/tazobactam, ceftazidime, cefepim, aztreonam, imipenem, meropenem, amykacin, gentamycin, tobramycin, ciprofloxacin, tigecyclin, fosfomycin, colistin, and timethoprim + sulfamethoxazole. All strains were genotyped by Rep-PCR (Diversilab-BioMérieux). All isolates originated from Portugal except the turtle isolates who were sampled in Sao Tomé.
International Journal of Infectious Diseases, 2014
Background: One of the greatest threat to the recent generation of antibiotics is the increasing ... more Background: One of the greatest threat to the recent generation of antibiotics is the increasing prevalence of bacterial resistant, specially Gram-negative bacteria. Acinetobacter baumanni is one of the most important superbugs becoming increasingly prevalent in patients with diabetes mellitus in Middle East particularly in Saudi Arabia. We have shown that diabetic patients are more susceptible to acquire infection with these type of superbugs A.baumannii than the rest of the population. Carbapenem resistance in A.baumannii limits therapeutic options and is largely manifested by -lactamases and metallo--lactamase that play a significant role in mechanisms of drug-resistance in diabetic patients. The aim is to investigate the level of threat of these pathogens to diabetics and the mechanisms of drug-resistance of patients in Saudi Arabia hospitals. Methods & Materials: A total of 64 non-repetitive, strains collected between 2008 to 2012 from different specimens from diabetic patients from King Faisal Specialist Hospital and Research Centre, Riyadh. All isolates were identified by Vitek system. Multiplex PCR using primers for bla OXA-51 combined with primers for bla OXA-23 , bla OXA-24/40 and bla OXA-58 was employed. PCR was used for detection of -lactamase and metallo--lactamase genes and insertion sequences IS elements. Pulsed-field gel electrophoresis (PFGE) has been performed. MICs was determined by dilution method. Results: Sixty-four clinical isolates of A. baumannii having bla OXA-51-like gene. All isolates were resistant to imipenem and meropenem (MIC > 16-32 mg/L) except four were intermediate (MIC = 8 mg/L) and Six were susceptible (MIC 0.5-2 mg/L) to both of them. All isolates were sensitive to tigecycline and colistin (MIC 0.5-2 mg/L) except four were resistant (MIC 8-32 mg/L) and three were intermediate to tigecycline only (MIC 4-8). The cause of resistance was from -lactamase of bla OXA-23 and bla OXA-24/40 and metallo--lactamase bla VIM and bla SPM. Fifty-nine isolates were possess the insertion sequence ISAba1. PFGE showed Nine clusters of bla OXA-51-like enzymes. Conclusion: Carbapenem-resistant Acinetobacter baumannii is a serious superbugs threaten diabetic patients due to the circulation of -lactamases and metallo--lactamase in Saudi Arabian hospitals. Furthermore, the emergence of tigecycline plus colistin resistance is causing a treatment shortfall for these patients.
Objectives: To rapidly detect transmission of Pseudomonas aeruginosa (P. aeruginosa) among cystic... more Objectives: To rapidly detect transmission of Pseudomonas aeruginosa (P. aeruginosa) among cystic fibrosis (CF) patients in a hospital environment, so that the necessary measures can be taken to avoid future transmissions. Methods: The use of molecular typing techniques such as rep-PCR (Diversilab ® , bioMérieux), in combination with multiplex PCR targeting ferripyoverdine receptor genes and S-type pyocin genes to distinguish between P. aeruginosa isolates. Conclusion: In order to quickly detect and respond to bacterial transmissions and outbreaks in hospitals, an appropriate detection method to identify these transmission events and strains is indispensable. Although the use of rep-PCR to determine the clonally relatedness of potential transmissible strains is very useful, we have shown that a combination of the latter technique together with a specific multiplex PCR targeting virulence factors such as ferripyoverdine receptors and pyocins allows for the accurate detection of transmission of P. aeruginosa among CF patients in a hospital environment. We showed that intra CF patient P. aeruginosa transmission can occur but that there is not really one highly transmissible CF clone spreading.
Cultures of human epithelial cells (keratinocytes) are used as an additional surgical tool to tre... more Cultures of human epithelial cells (keratinocytes) are used as an additional surgical tool to treat critically burnt patients. Initially, the production environment of keratinocyte grafts was regulated exclusively by national regulations. In 2004, the European Tissues and Cells Directive 2004/23/EC (transposed into Belgian Law) imposed requirements that resulted in increased production costs and no significant increase in quality and/or safety. In 2007, Europe published Regulation (EC) No 1394/2007 on Advanced Therapy Medicinal Products. Overnight, cultured keratinocytes became (arguably) "Advanced" Therapy Medicinal Products (ATMPs) to be produced as human medicinal products. The practical impact of these amendments was (and still is) considerable. A similar development appears imminent in bacteriophage therapy. Bacteriophages are bacterial viruses that can be used for tackling the problem of bacterial resistance development to antibiotics. Therapeutic natural bacteriopha...
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