Toxic epidermal necrolysis is the most severe form of drug-induced skin reaction and includes den... more Toxic epidermal necrolysis is the most severe form of drug-induced skin reaction and includes denudation of >30% of total body surface area. The mechanism of disease is not completely understood, but immunologic mechanisms, cytotoxic reactions, and delayed hypersensitivity seem to be involved. We report a case of cephazolin-induced toxic epidermal necrolysis treated with intravenous immunoglobulin and N-acetylcysteine with excellent response.
The epidemiological analysis of nosocomial pathogens is a subject of long-standing clinical inter... more The epidemiological analysis of nosocomial pathogens is a subject of long-standing clinical interest. In recent years, molecular techniques have received increasing attention as a means of analyzing epidemiological interrelationships, thus leading to use of the term molecular epidemiology . Since chromosomal DNA represents a fundamental molecule of cellular identity, there has been particular interest in assessing chromosomal similarity as a measure of epidemiological relatedness. One attractive approach has been to digest chromosomal DNA with restriction enzymes, resulting in a series of different sized fragments that form patterns when comparatively analyzed by agarose gel electrophoresis. In this context, differences in fragment patterns commonly are referred to as restriction-fragment length polymorphisms (RFLPs). Enzymes commonly used to cleave DNA typically recognize numerous sites within the bacterial chromosome. With such enzymes, restriction digestion of DNA from different bacterial isolates results in fragments that are too numerous to compare accurately after conventional agarose gel electrophoresis.
The American Journal of Tropical Medicine and Hygiene, 2021
ABSTRACTLeishmania RNA virus (LRV) is a double-stranded RNA virus belonging to the Totiviridae fa... more ABSTRACTLeishmania RNA virus (LRV) is a double-stranded RNA virus belonging to the Totiviridae family detected as cytoplasmic inclusions in some strains of the human parasite Leishmania spp. Experimental evidence supports the hypothesis that human coinfection with Leishmania spp.–LRV triggers an exacerbated immune response in the host that can be responsible for the observed complicated outcomes in cutaneous leishmaniasis (CL), such as mucosal leishmaniasis (ML) and treatment failure of CL. However, the reported frequencies of LRV associated with complicated outcomes in patient’s series are highly variable, diminishing the relevance on the virus presence in the pathogenesis of the disease. To assess whether or not the inconsistent information about the frequency of LRV associated with CL complicated outcomes could be related to the virus detection approach, the present study evaluated the LRV presence in clinical samples using a diagnostic algorithm according to the type of the samp...
Leishmania RNA virus (LRV) is a double strand RNA virus belonging to the Totiviridae family detec... more Leishmania RNA virus (LRV) is a double strand RNA virus belonging to the Totiviridae family detected as cytoplasmic inclusions in some strains of the human parasite Leishmania spp. Experimental evidence supports the hypothesis that human co-infection with Leishmania spp-LRV triggers an exacerbated immune response in the host that can be responsible for the observed complicated outcomes in cutaneous leishmaniasis (CL), such as mucosal leishmaniasis (ML) and treatment failure of cutaneous leishmaniasis (TFCL). However, the reported frequencies of LRV associated to complicated outcomes in patients’ series are highly variable, diminishing the relevance on the virus presence in the pathogenesis of the disease. For determining if the apparent inconsistent information about the frequency of LRV associated to CL complicated outcomes could be connected with the virus detection approach, this study tested previously described methods for LRV detection in clinical samples of patients according...
Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the mai... more Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the main cause of opportunistic mycosis at hospital settings. This study, made by members of the Colombian Association of Infectious Diseases (ACIN), was aimed at providing a set of recommendations for the management, follow-up and prevention of IC / candidemia and mucous membrane candida infection in adult, pediatric and neonatal patients in a hospital setting, including the hemato-oncological and critical care units. All the data obtained through an exhaustive search were reviewed and analyzed in a comprehensive manner by all the members of the group, and the recommendations issued are being made after a careful review of the scientific literature available and the consensus of all specialists involved; the emergence of Candida Spp. problem is highlighted and a correct orientation to health professionals regarding the management of patients with candidiasis is provided in a rational and pract...
Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the mai... more Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the main cause of opportunistic mycosis at hospital settings. This study, made by members of the Colombian Association of Infectious Diseases (ACIN), was aimed at providing a set of recommendations for the management, follow-up and prevention of IC / candidemia and mucous membrane candida infection in adult, pediatric and neonatal patients in a hospital setting, including the hemato-oncological and critical care units. All the data obtained through an exhaustive search were reviewed and analyzed in a comprehensive manner by all the members of the group, and the recommendations issued are being made after a careful review of the scientific literature available and the consensus of all specialists involved; the emergence of Candida Spp. problem is highlighted and a correct orientation to health professionals regarding the management of patients with candidiasis is provided in a rational and pract...
β-Lactam resistance in Pseudomonas aeruginosa clinical isolates is driven by a number of mechanis... more β-Lactam resistance in Pseudomonas aeruginosa clinical isolates is driven by a number of mechanisms. Whilst several are understood, how they act co-operatively in pathogenic strains is less clear. In some isolates, resistance profiles cannot always be explained by identifying the common resistance-determining pathways, suggesting that other mechanisms may be important. Pathogenic P. aeruginosa isolates from four countries were characterised by PCR. Quantitative expression analysis was also assessed for the activity of several pathways that influence antibiotic resistance, and culture experiments were conducted to test how random transposition of the insertion sequence IS26 during growth may influence resistance to some antibiotics. In most strains, antibiotic resistance was being driven by changes in multiple pathways and by the presence or absence of genes acquired by lateral gene transfer. Multiple mechanisms of resistance were prevalent in strains from all of the countries examined, although regional differences in the type of interacting mechanisms were apparent. Changes in chromosomal pathways included overexpression of AmpC and two efflux pumps. Also, gain or loss of IS26 at some chromosomal locations, most notably oprD, could influence resistance to carbapenems. IS26-related resistance was found in strains from Argentina and geographically linked Uruguay, but not in strains from either Colombia or Australia. Pseudomonas aeruginosa pathogenic strains are evolving to become multidrug-resistant in more complex ways. This is being influenced by single strains acquiring changes in numerous known pathways as well as by newly emerging resistance mechanisms in this species.
The Brazilian Journal of Infectious Diseases, 2014
Nosocomial infections caused by carbapenem-resistant Acinetobacter baumannii isolates have reache... more Nosocomial infections caused by carbapenem-resistant Acinetobacter baumannii isolates have reached epidemic levels in past decades. Currently this microorganism is responsible for outbreaks of difficult eradication and with high mortality rates worldwide. We herein report a rare case of an OXA-72-producing A. baumannii isolate colonizing a 47-year-old male patient with peritonitis due to abdominal stab wound, four years earlier than the first report of this carbapenemase in Acinetobacter pittii in Colombia. Although OXA-72 presents a low prevalence compared with OXA-23, our study demonstrated that A. baumannii isolates carrying the blaOXA-72 gene were present in the hospital environment in Colombia and could act as a reservoir for further spread to other Acinetobacter species, like A. pittii, causing carbapenem-resistance.
Toxic epidermal necrolysis is the most severe form of drug-induced skin reaction and includes den... more Toxic epidermal necrolysis is the most severe form of drug-induced skin reaction and includes denudation of >30% of total body surface area. The mechanism of disease is not completely understood, but immunologic mechanisms, cytotoxic reactions, and delayed hypersensitivity seem to be involved. We report a case of cephazolin-induced toxic epidermal necrolysis treated with intravenous immunoglobulin and N-acetylcysteine with excellent response.
The epidemiological analysis of nosocomial pathogens is a subject of long-standing clinical inter... more The epidemiological analysis of nosocomial pathogens is a subject of long-standing clinical interest. In recent years, molecular techniques have received increasing attention as a means of analyzing epidemiological interrelationships, thus leading to use of the term molecular epidemiology . Since chromosomal DNA represents a fundamental molecule of cellular identity, there has been particular interest in assessing chromosomal similarity as a measure of epidemiological relatedness. One attractive approach has been to digest chromosomal DNA with restriction enzymes, resulting in a series of different sized fragments that form patterns when comparatively analyzed by agarose gel electrophoresis. In this context, differences in fragment patterns commonly are referred to as restriction-fragment length polymorphisms (RFLPs). Enzymes commonly used to cleave DNA typically recognize numerous sites within the bacterial chromosome. With such enzymes, restriction digestion of DNA from different bacterial isolates results in fragments that are too numerous to compare accurately after conventional agarose gel electrophoresis.
The American Journal of Tropical Medicine and Hygiene, 2021
ABSTRACTLeishmania RNA virus (LRV) is a double-stranded RNA virus belonging to the Totiviridae fa... more ABSTRACTLeishmania RNA virus (LRV) is a double-stranded RNA virus belonging to the Totiviridae family detected as cytoplasmic inclusions in some strains of the human parasite Leishmania spp. Experimental evidence supports the hypothesis that human coinfection with Leishmania spp.–LRV triggers an exacerbated immune response in the host that can be responsible for the observed complicated outcomes in cutaneous leishmaniasis (CL), such as mucosal leishmaniasis (ML) and treatment failure of CL. However, the reported frequencies of LRV associated with complicated outcomes in patient’s series are highly variable, diminishing the relevance on the virus presence in the pathogenesis of the disease. To assess whether or not the inconsistent information about the frequency of LRV associated with CL complicated outcomes could be related to the virus detection approach, the present study evaluated the LRV presence in clinical samples using a diagnostic algorithm according to the type of the samp...
Leishmania RNA virus (LRV) is a double strand RNA virus belonging to the Totiviridae family detec... more Leishmania RNA virus (LRV) is a double strand RNA virus belonging to the Totiviridae family detected as cytoplasmic inclusions in some strains of the human parasite Leishmania spp. Experimental evidence supports the hypothesis that human co-infection with Leishmania spp-LRV triggers an exacerbated immune response in the host that can be responsible for the observed complicated outcomes in cutaneous leishmaniasis (CL), such as mucosal leishmaniasis (ML) and treatment failure of cutaneous leishmaniasis (TFCL). However, the reported frequencies of LRV associated to complicated outcomes in patients’ series are highly variable, diminishing the relevance on the virus presence in the pathogenesis of the disease. For determining if the apparent inconsistent information about the frequency of LRV associated to CL complicated outcomes could be connected with the virus detection approach, this study tested previously described methods for LRV detection in clinical samples of patients according...
Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the mai... more Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the main cause of opportunistic mycosis at hospital settings. This study, made by members of the Colombian Association of Infectious Diseases (ACIN), was aimed at providing a set of recommendations for the management, follow-up and prevention of IC / candidemia and mucous membrane candida infection in adult, pediatric and neonatal patients in a hospital setting, including the hemato-oncological and critical care units. All the data obtained through an exhaustive search were reviewed and analyzed in a comprehensive manner by all the members of the group, and the recommendations issued are being made after a careful review of the scientific literature available and the consensus of all specialists involved; the emergence of Candida Spp. problem is highlighted and a correct orientation to health professionals regarding the management of patients with candidiasis is provided in a rational and pract...
Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the mai... more Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the main cause of opportunistic mycosis at hospital settings. This study, made by members of the Colombian Association of Infectious Diseases (ACIN), was aimed at providing a set of recommendations for the management, follow-up and prevention of IC / candidemia and mucous membrane candida infection in adult, pediatric and neonatal patients in a hospital setting, including the hemato-oncological and critical care units. All the data obtained through an exhaustive search were reviewed and analyzed in a comprehensive manner by all the members of the group, and the recommendations issued are being made after a careful review of the scientific literature available and the consensus of all specialists involved; the emergence of Candida Spp. problem is highlighted and a correct orientation to health professionals regarding the management of patients with candidiasis is provided in a rational and pract...
β-Lactam resistance in Pseudomonas aeruginosa clinical isolates is driven by a number of mechanis... more β-Lactam resistance in Pseudomonas aeruginosa clinical isolates is driven by a number of mechanisms. Whilst several are understood, how they act co-operatively in pathogenic strains is less clear. In some isolates, resistance profiles cannot always be explained by identifying the common resistance-determining pathways, suggesting that other mechanisms may be important. Pathogenic P. aeruginosa isolates from four countries were characterised by PCR. Quantitative expression analysis was also assessed for the activity of several pathways that influence antibiotic resistance, and culture experiments were conducted to test how random transposition of the insertion sequence IS26 during growth may influence resistance to some antibiotics. In most strains, antibiotic resistance was being driven by changes in multiple pathways and by the presence or absence of genes acquired by lateral gene transfer. Multiple mechanisms of resistance were prevalent in strains from all of the countries examined, although regional differences in the type of interacting mechanisms were apparent. Changes in chromosomal pathways included overexpression of AmpC and two efflux pumps. Also, gain or loss of IS26 at some chromosomal locations, most notably oprD, could influence resistance to carbapenems. IS26-related resistance was found in strains from Argentina and geographically linked Uruguay, but not in strains from either Colombia or Australia. Pseudomonas aeruginosa pathogenic strains are evolving to become multidrug-resistant in more complex ways. This is being influenced by single strains acquiring changes in numerous known pathways as well as by newly emerging resistance mechanisms in this species.
The Brazilian Journal of Infectious Diseases, 2014
Nosocomial infections caused by carbapenem-resistant Acinetobacter baumannii isolates have reache... more Nosocomial infections caused by carbapenem-resistant Acinetobacter baumannii isolates have reached epidemic levels in past decades. Currently this microorganism is responsible for outbreaks of difficult eradication and with high mortality rates worldwide. We herein report a rare case of an OXA-72-producing A. baumannii isolate colonizing a 47-year-old male patient with peritonitis due to abdominal stab wound, four years earlier than the first report of this carbapenemase in Acinetobacter pittii in Colombia. Although OXA-72 presents a low prevalence compared with OXA-23, our study demonstrated that A. baumannii isolates carrying the blaOXA-72 gene were present in the hospital environment in Colombia and could act as a reservoir for further spread to other Acinetobacter species, like A. pittii, causing carbapenem-resistance.
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Papers by Carlos Saavedra