A combination of photodynamic therapy and antimicrobial compounds to treat skin and mucosal infections: a systematic review.

BACKGROUND: Antimicrobial photodynamic therapy (aPDT) is a growing approach to treat skin and mucosal infections. Despite its effectiveness, investigators have explored whether aPDT can be further combined with antibiotics and antifungal drugs. OBJECTIVE: To systematically assess the in vivo studies on the effectiveness of combinations of aPTD plus antimicrobials in the treatment of cutaneous and mucosal infections. MATERIALS AND METHODS: Searches were performed in four databases (PubMed, EMBASE, Cochrane library databases, ClinicaTrials.gov) until July 2018. The pooled information was evaluated according to the PRISMA guidelines. RESULTS: 11 full-text articles were finally evaluated and included. The best aPDT combinations involved 5-aminolevulinic acid or phenothiazinium dye-based aPDT. In general, the combination shows benefits such as reducing treatment times, lowering drug dosages, decreasing drug toxicity, improving patient compliance and diminishing the risk of developing resistance. The mechanism of action may be that first aPDT damages the microbial cell wall or membrane, which allows better penetration of the antimicrobial drug. LIMITATIONS: The number of studies was low, the protocols used were heterogeneous, and there was a lack of clinical trials. CONCLUSIONS: The additive or synergistic effect of aPDT combined with antimicrobials could be promising to manage skin and mucosal infections, helping to overcome the microbial drug resistance.

Klebsiella pneumoniae survives within macrophages by avoiding delivery to lysosomes.

Klebsiella pneumoniae is an important cause of community-acquired and nosocomial pneumonia. Evidence indicates that Klebsiella might be able to persist intracellularly within a vacuolar compartment. This study was designed to investigate the interaction between Klebsiella and macrophages. Engulfment of K. pneumoniae was dependent on host cytoskeleton, cell plasma membrane lipid rafts and the activation of phosphoinositide 3-kinase (PI3K). Microscopy studies revealed that K. pneumoniae resides within a vacuolar compartment, the Klebsiella-containing vacuole (KCV), which traffics within vacuoles associated with the endocytic pathway. In contrast to UV-killed bacteria, the majority of live bacteria did not co-localize with markers of the lysosomal compartment. Our data suggest that K. pneumoniae triggers a programmed cell death in macrophages displaying features of apoptosis. Our efforts to identify the mechanism(s) whereby K. pneumoniae prevents the fusion of the lysosomes to the KCV uncovered the central role of the PI3K-Akt-Rab14 axis to control the phagosome maturation. Our data revealed that the capsule is dispensable for Klebsiella intracellular survival if bacteria were not opsonized. Furthermore, the environment found by Klebsiella within the KCV triggered the down-regulation of the expression of cps. Altogether, this study proves evidence that K. pneumoniae survives killing by macrophages by manipulating phagosome maturation that may contribute to Klebsiella pathogenesis.

In Vivo IS6110 Profile Changes in a Mycobacterium tuberculosis Strain as Determined by Tracking over 14 Years.

Transposition and homologous recombination of IS6110 appear in Mycobacterium tuberculosis along in vivo sequential infections. These events were checked in different clones of a successful strain, M. tuberculosis Zaragoza, with the focus on a variant in which integration of a copy of IS6110 in the origin of replication (oriC) region occurred.

Global study of IS6110 in a successful Mycobacterium tuberculosis strain: clues for deciphering its behavior and for its rapid detection.

The Mycobacterium tuberculosis insertion sequence IS6110, besides being a very useful tool in molecular epidemiology, seems to have an impact on the biology of bacilli. In the present work, we mapped the 12 points of insertion of IS6110 in the genome of a successful strain named M. tuberculosis Zaragoza (which has been referred to as the MTZ strain). This strain, belonging to principal genetic group 3, caused a large unsuspected tuberculosis outbreak involving 85 patients in Zaragoza, Spain, in 2001 to 2004. The mapping of the points of insertion of IS6110 in the genome of the Zaragoza strain offers clues for a better understanding of the adaptability and virulence of M. tuberculosis. Surprisingly, the presence of one copy of IS6110 was found in Rv2286c, as was recently described for a successful Beijing sublineage. As a result of this analysis, a rapid method for detecting this particular M. tuberculosis strain has been designed.

Rapid test for identification of a highly transmissible Mycobacterium tuberculosis Beijing strain of sub-Saharan origin.

The development of a rapid test to identify Mycobacterium tuberculosis Beijing isolates and specifically strain GC1237, coming from a sub-Saharan country, is needed due to its alarming wide spread on Gran Canaria Island (Spain). A rapid test that detects IS6110 present between dnaA and dnaN in the Beijing strains and in a specific site for GC1237 (Rv2180c) has been developed. This test would be a useful tool in the surveillance of subsequent cases.

Successful control of Serratia marcescens outbreak in a neonatal unit of a tertiary-care hospital in Spain.

OBJECTIVE: Serratia marcescens is a Gram-negative bacterium that is found in hospital environments and commonly associated with outbreaks in neonatal units. One S. marcescens isolate was detected from a bloodstream culture from a neonate in our hospital that was followed by an outbreak. The aim of this study was to describe the molecular epidemiology of a S. marcescens outbreak in the neonatal unit. METHODS: In order to investigate the outbreak, weekly surveillance rectal swabs were submitted for culture from all patients admitted in this unit from August to September 2018. Environmental samples were obtained from potential sources in September 2018. Typing of isolates was performed by pulsed field gel electrophoresis (PFGE). In addition, we studied the in vitro activity of chlorhexidine against S. marcescens. RESULTS: During this period, 146 infants were hospitalised in our neonatal unit, of which 16 patients had a S. marcescens-positive sample. A total of 36 environmental surveillance samples were collected, and one sample from a stethoscope from an incubator of a colonized baby was positive for S. marcescens. All the 18 isolates, including the isolate from the stethoscope, belonged to a single PFGE cluster. We found that very low concentrations of chlorhexidine, even with application times close to 0 achieved significant reductions in the amount of S. marcescens. CONCLUSION: A unique clone of S. marcescens caused this outbreak, including isolates from patients and from one stethoscope. The outbreak was controlled with the early implementation of specific control measures.

Pacemaker-induced endocarditis by Gordonia bronchialis.

PURPOSE: Gordonia species are known to be opportunistic human pathogens causing secondary infections. We present the second case in the world of endocarditis caused by Gordonia bronchialis and a review of all the cases of endocarditis caused by Gordonia spp. METHODS: The identification was performed by matrix-assisted desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing were performed to confirm the identification. Antimicrobial susceptibility was performed by MIC test Strip on Mueller-Hinton agar supplemented with 5% defibrinated sheep blood according to Clinical and Laboratory Standards Institute. RESULTS: Pacemaker-induced endocarditis due to Gordonia bronchialis infection was determined in an 88-year old woman. The patient was treated with ceftriaxone and ciprofloxacin until completing 6 weeks from the pacemaker explant with a good evolution. CONCLUSION: The case presented supports the pathogenic role of Gordonia bronchialis as an opportunistic pathogen and highlights the high risk of suffering infections caused by environmental bacteria.

Successful control of Serratia marcescens outbreak in a neonatal unit of a tertiary-care hospital in Spain.

OBJECTIVE: Serratia marcescens is a Gram-negative bacterium that is found in hospital environments and commonly associated with outbreaks in neonatal units. One S. marcescens isolate was detected from a bloodstream culture from a neonate in our hospital that was followed by an outbreak. The aim of this study was to describe the molecular epidemiology of a S. marcescens outbreak in the neonatal unit. METHODS: In order to investigate the outbreak, weekly surveillance rectal swabs were submitted for culture from all patients admitted in this unit from August to September 2018. Environmental samples were obtained from potential sources in September 2018. Typing of isolates was performed by pulsed field gel electrophoresis (PFGE). In addition, we studied the in vitro activity of chlorhexidine against S. marcescens. RESULTS: During this period, 146 infants were hospitalised in our neonatal unit, of which 16 patients had a S. marcescens-positive sample. A total of 36 environmental surveillance samples were collected, and one sample from a stethoscope from an incubator of a colonized baby was positive for S. marcescens. All the 18 isolates, including the isolate from the stethoscope, belonged to a single PFGE cluster. We found that very low concentrations of chlorhexidine, even with application times close to 0 achieved significant reductions in the amount of S. marcescens. CONCLUSION: A unique clone of S. marcescens caused this outbreak, including isolates from patients and from one stethoscope. The outbreak was controlled with the early implementation of specific control measures.

Pacemaker-induced endocarditis by Gordonia bronchialis.

PURPOSE: Gordonia species are known to be opportunistic human pathogens causing secondary infections. We present the second case in the world of endocarditis caused by Gordonia bronchialis and a review of all the cases of endocarditis caused by Gordonia spp. METHODS: The identification was performed by matrix-assisted desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing were performed to confirm the identification. Antimicrobial susceptibility was performed by MIC test Strip on Mueller-Hinton agar supplemented with 5% defibrinated sheep blood according to Clinical and Laboratory Standards Institute. RESULTS: Pacemaker-induced endocarditis due to Gordonia bronchialis infection was determined in an 88-year old woman. The patient was treated with ceftriaxone and ciprofloxacin until completing 6 weeks from the pacemaker explant with a good evolution. CONCLUSION: The case presented supports the pathogenic role of Gordonia bronchialis as an opportunistic pathogen and highlights the high risk of suffering infections caused by environmental bacteria.

Comparing Two Automated Techniques for the Primary Screening-Out of Urine Culture.

Urinary tract infection is the most common human infection with a high morbidity. In primary care and hospital services, conventional urine culture is a key part of infection diagnosis but results take at least 24 h. Therefore, a rapid and reliable screening method is still needed to discard negative samples as quickly as possible and to reduce the laboratory workload. In this aspect, this study aims to compare the diagnostic performance between Sysmex UF-1000i and FUS200 systems in comparison to urine culture as the gold standard. From March to June 2016, 1,220 urine samples collected at the clinical microbiology laboratory of the "Miguel Servet" hospital were studied in parallel with both analysers, and some technical features were evaluated to select the ideal equipment. The most balanced cut-off values taking into account bacteria or leukocyte counts were 138 bacteria/µL or 119.8 leukocyte/µL for the UF-1000i (95.3% SE and 70.4% SP), and 5.7 bacteria/µL or 4.3 leukocyte/µL for the FUS200 (95.8% SE and 44.4% SP). The reduction of cultured plates was 37.4% with the FUS200 and 58.3% with the UF-1000i. This study shows that both techniques improve the workflow in the laboratory, but the UF-1000i has the highest specificity at any sensitivity and the FUS200 needs a shorter processing time.

Mycobacterium tuberculosis genotypes and predominant clones among the multidrug-resistant isolates in Spain 1998-2005.

Although the incidence of tuberculosis (TB) is gradually decreasing in Spain, there is an increase in the proportion of foreign-born cases. This changing scenario is slowly shifting the local TB epidemiology from endemic to imported cases with an increased risk for multidrug-resistant (MDR) and extensively drug resistant (XDR) strains of Mycobacterium tuberculosis complex. MDR/XDR strains from Spain (n=366 MTBC isolates, 1 strain per patient) isolated between 1998 and 2005 were retained for this retrospective analysis. All strains were analyzed by spoligotyping, while 12-loci MIRU-VNTR data were available for 106 isolates from 2003 to 2005. Demographic, phylogenetic, and epidemiologic analyses using anonymized data were collected and analyzed using the SITVIT2 database. Our study provides with a first snapshot of genetic diversity of MDR/XDR-TB in several autonomous regions of Spain. It highlights significantly more of SIT1/Beijing and SIT66/BOV MDR isolates (5.7% and 7.38% respectively) and increasingly more foreign-born cases from Eastern Europe. Future studies should focus on shared genotypes between Spanish and foreign-born patients to decipher the modes of transmission and risk factors involved, and decipher the proportion of imported cases of active disease versus cases of reactivation of latent TB infection among foreign-born individuals.

In-depth analysis of the genome sequence of a clinical, extensively drug-resistant Mycobacterium bovis strain.

Although human-to-human transmission of Mycobacterium bovis strains and other members of the animal lineage of the tubercle bacilli is a rare event, an extensively drug resistant (XDR) strain, named M. bovis B strain, caused a lethal outbreak in the nineties in Spain. The genome of M. bovis B strain was re-sequenced by SOLiD platform and mapped to the reference M. bovis AF2122/97. The genetic polymorphisms detected have been analysed in depth. One hundred and fifty-eight specific non-synonymous SNPs were detected; ninety-two of these were non-conservative. In addition, one specific 3195-bp insertion could be identified as an ABC transporter gene by homology with tbd2 gene, which was found to be present in other clinical M. bovis strains. Its peculiar phenotype profile of resistance was explained by molecular characteristics, including a 5685-bp specific deletion that revealed a novel polymorphism associated with resistance to paraminosalicilic acid. From a phylogenetical point of view, according to the SNPs detected, M. bovis B could be included into the clonal complex M. bovis European 2. This is the first time that a deep analysis of the whole-genome sequencing of an extensively drug-resistant M. bovis strain is detailed. It offers the explanation for the resistance and found several data to be incorporated for future research.