-
Microorganisms Aug 2019The genus has recently emerged as a cause of life-threatening infections in humans, particularly in immunocompromised patients. Several new species in the genus have... (Review)
Review
The genus has recently emerged as a cause of life-threatening infections in humans, particularly in immunocompromised patients. Several new species in the genus have been proposed in the last decade. Numerous studies have indicated that , rather than , is the most prevalent pathogen in this genus. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry systems with an extended spectrum database could reliably identify and , but they are unable to distinguish the remaining species. Precise species identification relies on molecular techniques, such as housekeeping gene sequencing and whole-genome sequencing. These microorganisms are usually susceptible to minocycline but resistant to most β-lactams, β-lactam/β-lactam inhibitors, carbapenems, and aminoglycosides. They often exhibit variable susceptibility to piperacillin, piperacillin-tazobactam, fluoroquinolones, and trimethoprim-sulfamethoxazole. Accordingly, treatment should be guided by antimicrobial susceptibility testing. Target gene mutations are markedly associated with fluoroquinolone resistance. Knowledge on the genomic characteristics provides valuable insights into in these emerging pathogens.
PubMed: 31466280
DOI: 10.3390/microorganisms7090295 -
Journal of Clinical Medicine Jan 2020Septicaemia likely results in high case-fatality rates in the present multidrug-resistant (MDR) era. Amongst them are hospital-acquired pneumonia (HAP) and... (Review)
Review
Septicaemia likely results in high case-fatality rates in the present multidrug-resistant (MDR) era. Amongst them are hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), two frequent fatal septicaemic entities amongst hospitalised patients. We reviewed the PubMed database to identify the common organisms implicated in HAP/VAP, to explore the respective risk factors, and to find the appropriate antibiotic choice. Apart from methicillin-resistant and , extended-spectrum β-lactamase-producing Enterobacteriaceae spp., MDR or extensively drug-resistant (XDR)- complex spp., followed by , , and are ranked as the top Gram-negative bacteria (GNB) implicated in HAP/VAP. Carbapenem-resistant Enterobacteriaceae notably emerged as an important concern in HAP/VAP. The above-mentioned pathogens have respective risk factors involved in their acquisition. In the present XDR era, tigecycline, colistin, and ceftazidime-avibactam are antibiotics effective against the carbapenemase and oxacillinase producers amongst the Enterobacteriaceae isolates implicated in HAP/VAP. Antibiotic combination regimens are recommended in the treatment of MDR/XDR- or complex isolates. Some special patient populations need prolonged courses (>7-day) and/or a combination regimen of antibiotic therapy. Implementation of an antibiotic stewardship policy and the measures recommended by the United States (US) Institute for Healthcare were shown to decrease the incidence rates of HAP/VAP substantially.
PubMed: 31963877
DOI: 10.3390/jcm9010275 -
Microorganisms Apr 2022spp. is a ubiquitous pathogenic bacterium that has been identified as the causal agent for a variety of conditions such as meningitis, pneumonia, necrotizing fasciitis,... (Review)
Review
spp. is a ubiquitous pathogenic bacterium that has been identified as the causal agent for a variety of conditions such as meningitis, pneumonia, necrotizing fasciitis, endophthalmitis, and sepsis and is emerging as a global threat including in Southeast Asia. infections tend to be associated with high mortality rates (18.2-41%) and are mostly observed in neonates and immunocompromised patients. Difficulties in precisely identifying at the species level by traditional methods have hampered our understanding of this genus in human infections. In Southeast Asian countries, hospital outbreaks have usually been ascribed to , whereas in Singapore, was reported as the main spp. associated with hospital settings. Misidentification of spp. could, however, underestimate the number of cases attributed to the bacterium, as precise identification requires tools such as MALDI-TOF MS, and particularly whole-genome sequencing, which are not available in most hospital laboratories. spp. has an unusual antibiotic resistance pattern for a Gram-negative bacterium with a limited number of horizontal gene transfers, which suggests an intrinsic origin for its multidrug resistance. Efforts to prevent and further understand spp. infections and limit its spread must rise to this new challenge.
PubMed: 35630327
DOI: 10.3390/microorganisms10050882 -
Malaria Journal May 2021Mosquito species from the Anopheles gambiae complex and the Anopheles funestus group are dominant African malaria vectors. Mosquito microbiota play vital roles in...
BACKGROUND
Mosquito species from the Anopheles gambiae complex and the Anopheles funestus group are dominant African malaria vectors. Mosquito microbiota play vital roles in physiology and vector competence. Recent research has focused on investigating the mosquito microbiota, especially in wild populations. Wild mosquitoes are preserved and transported to a laboratory for analyses. Thus far, microbial characterization post-preservation has been investigated in only Aedes vexans and Culex pipiens. Investigating the efficacy of cost-effective preservatives has also been limited to AllProtect reagent, ethanol and nucleic acid preservation buffer. This study characterized the microbiota of African Anopheles vectors: Anopheles arabiensis (member of the An. gambiae complex) and An. funestus (member of the An. funestus group), preserved on silica desiccant and RNAlater solution.
METHODS
Microbial composition and diversity were characterized using culture-dependent (midgut dissections, culturomics, MALDI-TOF MS) and culture-independent techniques (abdominal dissections, DNA extraction, next-generation sequencing) from laboratory (colonized) and field-collected mosquitoes. Colonized mosquitoes were either fresh (non-preserved) or preserved for 4 and 12 weeks on silica or in RNAlater. Microbiota were also characterized from field-collected An. arabiensis preserved on silica for 8, 12 and 16 weeks.
RESULTS
Elizabethkingia anophelis and Serratia oryzae were common between both vector species, while Enterobacter cloacae and Staphylococcus epidermidis were specific to females and males, respectively. Microbial diversity was not influenced by sex, condition (fresh or preserved), preservative, or preservation time-period; however, the type of bacterial identification technique affected all microbial diversity indices.
CONCLUSIONS
This study broadly characterized the microbiota of An. arabiensis and An. funestus. Silica- and RNAlater-preservation were appropriate when paired with culture-dependent and culture-independent techniques, respectively. These results broaden the selection of cost-effective methods available for handling vector samples for downstream microbial analyses.
Topics: Animals; Anopheles; Bacteria; Microbiota; Mosquito Vectors; Preservation, Biological; South Africa; Specimen Handling
PubMed: 34022891
DOI: 10.1186/s12936-021-03754-7 -
Saudi Medical Journal Mar 2020To describe the epidemiological, clinical, and outcome data of patients infected or colonized with Chryseobacterium/Elizabethkingia spp including antibiotic...
OBJECTIVES
To describe the epidemiological, clinical, and outcome data of patients infected or colonized with Chryseobacterium/Elizabethkingia spp including antibiotic susceptibility patterns.
METHODS
This retrospective study was conducted at Prince Sultan Military Medical City, Riyadh, Saudi Arabia. All patients infected or colonized by Chryseobacterium /Elizabethkingia spp who were admitted between June 2013 and May 2019 were included. Data were extracted from patient electronic medical records.
RESULTS
We enrolled 27 patients (13 males and 14 females) with a mean age of 35.6 years. Chryseobacterium/Elizabethkingia spp were isolated from blood cultures (n=13, 48%) and tracheal aspirations (n=11, 41%). The most frequent species isolated was Elizabethkingia meningoseptica (n=22). Although 6 patients were considered colonized, the remaining 21 patients presented with ventilator associated pneumonia (n=9), central line associated bloodstream infection (n=4), septic shock (n=4), or isolated bacteremia (n=4). In 25 cases the infections were health-care related. Three patients (11%) died within 28 days. Twenty-six isolates (96.5%) were resistant to carbapenems. Moxifloxacin and cotrimoxazole were the most active antibiotics.
CONCLUSION
Chryseobacterium/Elizabethkingia spp infection is rare, but can be responsible for severe hospital acquired infections. Cotrimoxazole and fluoroquinolone are the most effective antibiotic treatments.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Child; Child, Preschool; Chryseobacterium; Drug Resistance, Bacterial; Female; Flavobacteriaceae Infections; Humans; Infant; Infant, Newborn; Male; Middle Aged; Moxifloxacin; Retrospective Studies; Saudi Arabia; Trimethoprim, Sulfamethoxazole Drug Combination; Young Adult
PubMed: 32114605
DOI: 10.15537/smj.2020.3.24985 -
MBio Dec 2022The mosquito microbiota has a profound impact on multiple biological processes ranging from reproduction to disease transmission. Interestingly, the adult mosquito...
The mosquito microbiota has a profound impact on multiple biological processes ranging from reproduction to disease transmission. Interestingly, the adult mosquito microbiota is largely derived from the larval microbiota, which in turn is dependent on the microbiota of their water habitat. The larval microbiota not only plays a crucial role in larval development but also has a significant impact on the adult stage of the mosquito. By precisely engineering the larval microbiota, it is feasible to alter larval development and other life history traits of the mosquitoes. Bacteriophages, given their host specificity, can serve as a tool for modulating the microbiota. For this proof-of-principle study, we selected representative strains of five common mosquito-associated bacterial genera, namely, Enterobacter, Serratia, Pseudomonas, Elizabethkingia, and Asaia. Our results with monoaxenic cultures showed that larvae with Enterobacter and Pseudomonas displayed normal larval development with no significant mortality. However, monoaxenic larvae with showed delayed larval development and higher mortality. and gnotobiotic larvae failed to develop past the first instar. We isolated and characterized three novel bacteriophages (EP1, SP1, and EKP1) targeting Enterobacter, and respectively, and utilized a previously characterized bacteriophage (GH1) targeting Pseudomonas to modulate larval water microbiota. Gnotobiotic larvae with all five bacterial genera showed reduced survival and larval development with the addition of bacteriophages EP1 and GH1, targeting Enterobacter and Pseudomonas, respectively. The effect was synergistic when both EP1 and GH1 were added together. Our results demonstrate a novel application of bacteriophages for mosquito control. Mosquitoes are efficient vectors of multiple human and animal pathogens. The biology of mosquitoes is strongly affected by their associated microbiota. Because of the important role of the larval microbiota in mosquito biology, the microbiota can potentially serve as a target for altering mosquito life-history traits. Our study provides proof of principle that bacteriophages can be used as tools to modulate the mosquito larval habitat microbiota and can, in turn, affect larval development and survival. These results highlight the utility of bacteriophages in mosquito microbiota research and also provide a new potential mosquito control tool.
Topics: Animals; Humans; Mosquito Vectors; Larva; Phage Therapy; Flavobacteriaceae Infections; Bacteria; Water
PubMed: 36445694
DOI: 10.1128/mbio.03017-22 -
Antibiotics (Basel, Switzerland) Feb 2021(1) : spp. is an emerging nosocomial pathogen which causes mostly blood stream infection and nosocomial pneumonia. Among species, is the major pathogen, but...
(1) : spp. is an emerging nosocomial pathogen which causes mostly blood stream infection and nosocomial pneumonia. Among species, is the major pathogen, but misidentification as is a common problem. also possesses broad antibiotic resistance, resulting in high morbidity and mortality of the infection. The aim of our study was to review intra-abdominal infections and investigate resistance mechanisms against TMP/SMX in by whole genome sequencing. (2) : We retrospectively searched records of patients with intra-abdominal infection between 1990 and 2019. We also conducted whole genome sequencing for a TMP/SMX-resistant to identify possible mechanisms of resistance. (3) : We identified a total of nine cases of intra-abdominal infection in a review of the literature, including our own case. The cases included three biliary tract infections, three CAPD-related infection, two with infected ascites, and two postoperation infections. Host factor, indwelling-catheter, and previous invasive procedure, including surgery, play important roles in infection. Removal of the catheter is crucial for successful treatment. Genomic analysis revealed accumulated mutations leading to TMP/SMX-resistance in . (4) : Patients with underlying disease and indwelling catheter are more susceptible to intra-abdominal infection, and successful treatment requires removal of the catheter. The emerging resistance to TMP/SMX may be related to accumulated mutations in .
PubMed: 33572268
DOI: 10.3390/antibiotics10020173 -
Revista Espanola de Quimioterapia :... Sep 2021The global pandemic of COVID-19 has had negative repercussions on the activities and research in clinical microbiology laboratories other than those related to... (Review)
Review
The global pandemic of COVID-19 has had negative repercussions on the activities and research in clinical microbiology laboratories other than those related to SARS-CoV-2. Nonetheless, the research activity has also continued in other fields. In this brief review, some of the recent publications related to new diagnostic tests, methods for rapid antimicrobial susceptibility testing and for the detection of resistance genes, new diagnostic technologies, and some aspects related to old and emergent pathogens (Candida auris, Elizabethkingia spp. Streptococcus pyogenes) are summarized.
Topics: COVID-19; Candida; Humans; Pandemics; SARS-CoV-2
PubMed: 34598413
DOI: 10.37201/req/s01.01.2021 -
The Journal of Antimicrobial... Feb 2021We aimed to determine susceptibilities of Elizabethkingia spp. to 25 commonly tested and 8 novel antibiotics, and to compare the performance of different susceptibility...
OBJECTIVES
We aimed to determine susceptibilities of Elizabethkingia spp. to 25 commonly tested and 8 novel antibiotics, and to compare the performance of different susceptibility testing methods.
METHODS
Clinical isolates of Elizabethkingia spp., Chryseobacterium spp. and Flavobacterium spp. collected during 2002-18 (n = 210) in a nationwide surveillance programme in Taiwan were speciated by 16S rRNA sequencing. MICs were determined by broth microdilution. The broth microdilution results of 18 common antibiotics were compared with those obtained by the VITEK 2 automated system.
RESULTS
Among the Elizabethkingia spp. identified (n = 108), Elizabethkingia anophelis was the most prevalent (n = 90), followed by Elizabethkingia meningoseptica (n = 7) and Elizabethkingia miricola cluster [E. miricola (n = 6), Elizabethkingia bruuniana (n = 3) and Elizabethkingia ursingii (n = 2)]. Most isolates were recovered from respiratory or blood specimens from hospitalized, elderly patients. PFGE showed two major and several minor E. anophelis clones. All isolates were resistant to nearly all the tested β-lactams. Doxycycline, minocycline and trimethoprim/sulfamethoxazole inhibited >90% of Elizabethkingia spp. Rifampin inhibited E. meningoseptica (100%) and E. anophelis (81.1%). Fluoroquinolones and tigecycline were active against E. meningoseptica and E. miricola cluster isolates. Novel antibiotics, including imipenem/relebactam, meropenem/vaborbactam, ceftazidime/avibactam, cefepime/zidebactam, delafloxacin, eravacycline and omadacycline were ineffective but lascufloxacin inhibited half of Elizabethkingia spp. The very major discrepancy rates of VITEK 2 were >1.5% for ciprofloxacin, moxifloxacin and vancomycin. Major discrepancy rates were >3% for amikacin, tigecycline, piperacillin/tazobactam and trimethoprim/sulfamethoxazole.
CONCLUSIONS
MDR, absence of standard interpretation criteria and poor intermethod concordance necessitate working guidelines to facilitate future research of emerging Elizabethkingia spp.
Topics: Aged; Anti-Bacterial Agents; Flavobacteriaceae; Flavobacteriaceae Infections; Humans; Microbial Sensitivity Tests; RNA, Ribosomal, 16S; Taiwan
PubMed: 33258923
DOI: 10.1093/jac/dkaa499 -
Scientific Reports Feb 2021Muscle is an important structural tissue in aquatic animals and it is susceptible to bacterial and fungal infection, which could affect flesh quality and health. In this...
Investigation of Proteus vulgaris and Elizabethkingia meningoseptica invasion on muscle oxidative stress and autophagy in Chinese soft-shelled turtle (Pelodiscus sinensis).
Muscle is an important structural tissue in aquatic animals and it is susceptible to bacterial and fungal infection, which could affect flesh quality and health. In this study, Chinese soft-shelled turtles were artificially infected with two pathogens, Proteus vulgaris and Elizabethkingia meningoseptica and the effects on muscle nutritional characteristics, oxidative stress and autophagy were assayed. Upon infection, the muscle nutritional composition and muscle fiber structure were notably influenced. Meanwhile, the mRNA expression of Nrf2 was down-regulated and Keap1 up-regulated, thus resulting in a decrease in antioxidant capacity and oxidative stress. However, with N-acetylcysteine treatment, the level of oxidative stress was decreased, accompanied by significant increases in antioxidant enzyme activities and the mRNA levels of SOD, CAT, GSTCD, and GSTO1. Interestingly, there was a significant increase in autophagy in the muscle tissue after the pathogen infection, but this increase could be reduced by N-acetylcysteine treatment. Our findings suggest that muscle nutritional characteristics were dramatically changed after pathogen infection, and oxidative stress and autophagy were induced by pathogen infection. However, N-acetylcysteine treatment could compromise the process perhaps by decreasing the ROS level and regulating Nrf2-antioxidant signaling pathways.
Topics: Acetylcysteine; Animals; Antioxidants; Autophagy; China; Flavobacteriaceae; Flavobacteriaceae Infections; Muscles; Oxidative Stress; Proteus vulgaris; Signal Transduction; Turtles
PubMed: 33574492
DOI: 10.1038/s41598-021-83388-6