-
Mikrobiyoloji Bulteni Oct 2021Fungal peritonitis is less commonly seen than bacterial peritonitis in patients undergoing peritoneal dialysis (PD), but it is a serious complication with high morbidity...
Fungal peritonitis is less commonly seen than bacterial peritonitis in patients undergoing peritoneal dialysis (PD), but it is a serious complication with high morbidity and mortality. It often results in catheter loss and modifying therapy from PD to hemodialysis. The causative organisms are often Candida species. In this report, a PD-associated peritonitis caused by Wickerhamomyces anomalus (Candida pelliculosa), a rare fungal infection agent with increasing clinical importance by causing different clinical pictures was presented. An outpatient peritoneal fluid culture was sent from a 48-yearold male patient, who had been undergoing continuous peritoneal dialysis (CAPD) for 9 years, due to abdominal pain and blur in peritoneal fluid during dialysis. The patient admitted to the emergency department four days later due to the persistence of his complaints. A sample of peritoneal fluid was taken in the emergency department and sent to the laboratory for microbiological analysis. In the direct microscopical examination of the peritoneal fluid; cell number was determined as 210/mm3, and no microorganisms were seen in the Gram and methylene blue staining. The patient was admitted to the nephrology service with a pre-diagnosis of PD-associated peritonitis. Enterobacter aerogenes was grown in the peritoneal fluid culture which was sent from the dialysis outpatient clinic four days ago. The peritoneal fluid sample sent from the emergency department was inoculated on 5% sheep blood , EMB and chocolate agars and no growth was detected. As the patient's complaints and peritoneal fluid leukocyte count continued to increase, peritoneal fluid cultures were repeated and recurrent growth of yeast was detected in cultures. The yeast was identified as Candida pelliculosa by matrix assisted laser desorption ionization time-of-flight mass spectrofotometry (MALDI-TOF) VITEK®MS (bioMerieux, France). The species identification was confirmed by sequencing the target ITS gene regions on the rRNA and the isolate was identified as 100% Wickerhamomyces anomalus (sexual reproduction form of Candida pelliculosa, teleomorph). The reference microdilution method was performed according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI) in order to test the antifungal susceptibility. After 24 hour incubation, the minimal inhibitory concentrations (MIC) were determined as 0.03 μg/ml for amphotericin B, 0.125 μg/ml for caspofungin 0.125 μg/ml for voriconazole, 0.03 μg/ ml for itraconazole and 4 μg/ml for fluconazole. Fluconazole and anidulafungin were started for the treatment of fungal peritonitis. The patient's peritoneal dialysis catheter was removed and hemodialysis was applied to the patient. Clinical and laboratory symptoms regressed with antifungal therapy and the patient's anidulafungin treatment was discontinued for 14 days after the catheter removal. In conclusion, in patients undergoing CAPD, as in our case, fungal pathogens should also be considered although it is rare, when there is no laboratory and clinical improvement, and the response to treatment is not complete in PD-associated peritonitis to prevent delays in diagnosis and treatment.
Topics: Animals; Antifungal Agents; Candida; Humans; Male; Peritoneal Dialysis; Peritonitis; Saccharomycetales; Sheep
PubMed: 34666666
DOI: 10.5578/mb.20219718 -
Antimicrobial Resistance and Infection... Aug 2021Despite compliance to extensive reprocessing protocols, duodenoscopes have been linked to outbreaks of susceptible and multi-drug resistant organisms (MDRO) due to...
BACKGROUND
Despite compliance to extensive reprocessing protocols, duodenoscopes have been linked to outbreaks of susceptible and multi-drug resistant organisms (MDRO) due to persistent duodenoscope contamination. Duodenoscope-associated infections (DAIs) based on transmission of susceptible microorganisms are likely to be underreported due to detection bias.
CASE PRESENTATION
We describe the retrospective detection of a DAI case caused by a susceptible microorganism which at the time of clinical infection was not recognized as such. During 2017 and 2018, duodenoscopes were cultured on a daily basis due to research activities. While analyzing this data, it was found that a duodenoscope had been contaminated with Enterobacter cloacae complex over a period of 3 months. We checked whether patients treated with this duodenoscope had developed infections and found one patient with an E. cloacae cholangitis 3 months after the ERCP (Endoscopic retrograde cholangiopancreaticography) procedure. The isolates on the duodenoscope and in the patients' blood culture were indistinguishable by amplified fragment length polymorphism (AFLP). By classical multi-locus sequence typing (MLST), both strains were of the same (but novel) sequence type. Application of whole genome MLST showed 93 (out of 3757) allelic differences.
CONCLUSION
This case report describes a plausible link between a contaminated duodenoscope and a patient infection with E. cloacae. Transmission of susceptible E. cloacae was highly suspected from AFLP and MLST results; by WGS, 93 allelic differences were found which proves closely related strains. This report shows that DAIs by susceptible microorganisms can be easily missed and therefore its true prevalence remains underscored.
Topics: Amplified Fragment Length Polymorphism Analysis; Cross Infection; Duodenoscopes; Enterobacter cloacae; Enterobacteriaceae Infections; Equipment Contamination; Humans; Multilocus Sequence Typing
PubMed: 34454611
DOI: 10.1186/s13756-021-00996-7 -
Poultry Science Sep 2021Since its first appearance in 1996, H9N2 avian influenza virus (AIV) of the Y439 lineage persisted in Korean live bird markets (LBMs) until the last documented...
Pathogenicity of H9N2 low pathogenic avian influenza viruses of different lineages isolated from live bird markets tested in three animal models: SPF chickens, Korean native chickens, and ducks.
Since its first appearance in 1996, H9N2 avian influenza virus (AIV) of the Y439 lineage persisted in Korean live bird markets (LBMs) until the last documented occurrence in 2018. However, in June 2020, the avian influenza surveillance program detected a novel H9N2 AIV belonging to the Y280 lineage, which has zoonotic potential, in a Korean native chicken (KNC) from a LBM. In this study, we infected KNCs and ducks (the 2 major species held at LBMs), as well as SPF chickens, with Y280-lineage H9N2 AIV LBM261/20 and Y439-equivalent LBM294/18 to compare pathogenicity and transmissibility. In SPF chickens, LBM261/20 replicated mostly in the respiratory tract and spread rapidly among birds. By contrast, LBM294/18 replicated preferentially in the gastrointestinal tract and transmitted more slowly than LBM261/20. LBM261/20 replicated for a longer time in KNCs than in SPF chickens, and only in the respiratory tract; by contrast, LBM294/18 was detected in the oropharynx and cloaca. Ducks did not shed either virus or seroconvert. Taken together, the data suggest that the scheme used to monitor the newly introduced H9N2 AIV of the Y280 lineage needs to be modified to place emphasis on oropharyngeal sampling. Such changes will facilitate better disease control and protect public health.
Topics: Animals; Chickens; Ducks; Influenza A Virus, H9N2 Subtype; Influenza in Birds; Republic of Korea; Virulence
PubMed: 34284181
DOI: 10.1016/j.psj.2021.101318 -
Microbiology Insights 2021DDT is one of the most persistent pesticides among all the different types of organo-chlorine pesticides used. Among all the degradation methods, bacterial degradation...
Isolation and Characterization of a Bacterial Strain (Accession No. KX438060.1) Capable of Degrading DDTs Under Aerobic Conditions and Its Use in Bioremediation of Contaminated Soil.
DDT is one of the most persistent pesticides among all the different types of organo-chlorine pesticides used. Among all the degradation methods, bacterial degradation of DDT is most effective. The present study was conducted to isolate different bacteria present in waste samples which have the ability to degrade DDT present in the soil in the minimum possible period of time and to observe the effect of different physical and chemical properties of the soil samples. Many pesticide degrading bacteria were isolated and identified through cultural, biochemical tests and further identified by 16S RNA sequencing method. The most potent strain DDT 1 growth in mineral salt medium supplemented with DDT as the only source of carbon (5-100 PPM) and was monitored at an optical density of 600 nm. The growth parameters at different physio-chemical conditions were further optimized. The result showed that had maximum growth in 15 days. FTIR analysis of the residual DDT after 15 days incubation showed that was able to degrade pesticide into its further metabolites of DDD, DDE, DDNU and other components can be used for biodegradation of DDT present in contaminated soil and water ecosystems.
PubMed: 34177271
DOI: 10.1177/11786361211024289 -
Euro Surveillance : Bulletin Europeen... May 2021The hospital water environment, including the wastewater drainage system, is increasingly reported as a potential reservoir for carbapenemase-producing Enterobacterales...
The hospital water environment, including the wastewater drainage system, is increasingly reported as a potential reservoir for carbapenemase-producing Enterobacterales (CPE). We investigated a persistent outbreak of OXA-48 CPE (primarily ) in a haematological ward of a French teaching hospital by epidemiological, microbiological and environmental methods. Between January 2016 and June 2019, we detected 37 new OXA-48 CPE-colonised and/or ‑infected patients in the haematological ward. In October 2017, a unit dedicated to CPE-colonised and/or ‑infected patients was created. Eleven additional sporadic acquisitions were identified after this date without any obvious epidemiological link between patients, except in one case. Environmental investigations of the haematological ward (June-August 2018) identified seven of 74 toilets and one of 39 drains positive for OXA-48 CPE (seven , one , one ). Whole genome comparisons identified a clonal dissemination of OXA-48-producing from the hospital environment to patients. In addition to strict routine infection control measures, an intensive cleaning programme was performed (descaling and bleaching) and all toilet bowls and tanks were changed. These additional measures helped to contain the outbreak. This study highlights that toilets can be a possible source of transmission of OXA-48 CPE.
Topics: Bacterial Proteins; Citrobacter freundii; Cronobacter sakazakii; Cross Infection; Disease Outbreaks; Disease Reservoirs; Enterobacteriaceae Infections; Escherichia coli; France; Hospitals; Humans; Infection Control; Toilet Facilities; Water Microbiology; beta-Lactamases
PubMed: 34047273
DOI: 10.2807/1560-7917.ES.2021.26.21.2000118 -
Access Microbiology 2021Multidrug-resistant bacteria have been increasingly described in healthcare institutions, however community resistance also seems to be emerging. an intestinal...
Multidrug-resistant bacteria have been increasingly described in healthcare institutions, however community resistance also seems to be emerging. an intestinal commensal bacteria, is also a pathogen and represents an important intestinal reservoir of resistance. Our aim was the study of the intestinal colonization and of the persistence of antibiotic resistant intestinal bacteria in healthy university students of Porto, in the north of Portugal. Samples from 30 university students were collected and analysed. Two isolates were randomly obtained from each student and Gram-negative bacilli resistant to antibiotics were studied. In addition, we evaluated changes in the Gram-negative intestinal colonization of ten university students in a short period of time. Molecular characterization showed a high presence of in commensal . Gram-negative bacteria with intrinsic and extrinsic resistance were isolated, namely spp., spp. and spp. We isolated three ESBL-producing from two students. These isolates showed group 1 (=1), group 9 (=2), (=2), (=1) and (=2) genes. Additionally, they showed specific virulence factors and conjugational transfer of antibiotic resistance and virulence genes. One spp. isolate resistant to carbapenems was detected colonizing one student. Our results confirm that healthy young adults may be colonized with commensals showing clinically relevant antibiotic resistance mechanisms, creating a risk of silent spread of these bacteria in the community.
PubMed: 33997613
DOI: 10.1099/acmi.0.000182 -
Research and Reports in Tropical... 2021Patient-care equipment and inanimate objects contaminated with bacteria are a persistent problem in countries like Ethiopia, and remain overlooked. This study aimed to...
Magnitude, Diversity, and Antibiograms of Bacteria Isolated from Patient-Care Equipment and Inanimate Objects of Selected Wards in Arba Minch General Hospital, Southern Ethiopia.
INTODUCTION
Patient-care equipment and inanimate objects contaminated with bacteria are a persistent problem in countries like Ethiopia, and remain overlooked. This study aimed to elucidate the magnitude of contaminations, diversity, and antimicrobial-susceptibility patterns of bacterial isolates from selected wards of Arba Minch General Hospital, Ethiopia.
METHODS
Samples were inoculated into bacteriological media and identified by biochemical characterization, followed by antimicrobial-susceptibility tests.
RESULTS
Of the 99 inanimate objects and items of patient-care equipment examined, 71 (71.7%) showed contamination: 26 (76.4%) from the surgical ward and 22 (66.6%) and 23 (71.8%), respectively, from the pediatric ward and neonatal intensive care unit. In the case of Gram-positive bacteria, coagulase-negative staphylococci (CoNS; 52.2%) were predominant, followed by (47.7%), whereas common Gram-negative counterparts were spp. (28.5%) and spp. (23.8%). Antibiograms of and CoNS showed 100% and 78% resistance, respectively, against penicillin. Isolates of spp. showed 100% resistance to ceftriaxone and ampicillin, whereas those of spp. displayed complete resistance against ampicillin and trimethoprim-sulfamethoxazole. All isolates of spp., spp., spp., , and spp. exhibited 100% resistance to amoxicillin, ampicillin, and trimethoprim-sulfamethoxazole. Overall prevalence of multidrug-resistant bacteria was 57.7%.
CONCLUSION
A stringent infection-vigilance program comprising routine sampling from equipment and inanimate objects combined with antimicrobial-resistance surveillance and decontamination efforts must be instituted promptly.
PubMed: 33976582
DOI: 10.2147/RRTM.S301215 -
Journal of Bacteriology Jun 2021Proteolysis is a fundamental property of all living cells. In the bacterium Salmonella enterica serovar Typhimurium, the HspQ protein controls the specificities of the...
Proteolysis is a fundamental property of all living cells. In the bacterium Salmonella enterica serovar Typhimurium, the HspQ protein controls the specificities of the Lon and ClpAP proteases. Upon acetylation, HspQ stops being a Lon substrate and no longer enhances proteolysis of the Lon substrate Hha. The accumulated HspQ protein binds to the protease adaptor ClpS, hindering proteolysis of ClpS-dependent substrates of ClpAP, such as Oat, a promoter of antibiotic persistence. HspQ is acetylated by the protein acetyltransferase Pat from acetyl coenzyme A (acetyl-CoA) bound to the acetyl-CoA binding protein Qad. We now report that low cytoplasmic Mg promotes expression, which protects substrates of Lon and ClpSAP by increasing HspQ amounts. The promoter is activated by PhoP, a regulatory protein highly activated in low cytoplasmic Mg that also represses transcription. Both the gene and PhoP repression of the promoter are necessary for antibiotic persistence. PhoP also promotes transcription in Escherichia coli, which shares a similar PhoP box in the promoter region with Typhimurium, Salmonella bongori, and Enterobacter cloacae. Our findings identify cytoplasmic Mg and the PhoP protein as critical regulators of protease specificity in multiple enteric bacteria. The bacterium Salmonella enterica serovar Typhimurium narrows down the spectrum of substrates degraded by the proteases Lon and ClpAP in response to low cytoplasmic Mg, a condition that decreases protein synthesis. This control is exerted by PhoP, a transcriptional regulator activated in low cytoplasmic Mg that governs proteostasis and is conserved in enteric bacteria. The uncovered mechanism enables bacteria to control the abundance of preexisting proteins.
Topics: Bacterial Proteins; Cytoplasm; Gene Expression Regulation, Bacterial; Heat-Shock Proteins; Magnesium; Protease La; Salmonella typhimurium; Substrate Specificity
PubMed: 33941609
DOI: 10.1128/JB.00143-21 -
Infection and Drug Resistance 2021Antimicrobial resistance, especially carbapenem resistance Enterobacteriaceae and plasmid mediated mobile colistin resistance, is a serious issue worldwide. This study...
PURPOSE
Antimicrobial resistance, especially carbapenem resistance Enterobacteriaceae and plasmid mediated mobile colistin resistance, is a serious issue worldwide. This study was designed to determine the epidemiological characteristics of plasmid mediated colistin resistance and carbapenem resistant Enterobacteriaceae from tertiary A hospital located in Hefei, China.
METHODS
Totally, 158 carbapenems resistant Enterobacteriaceae (CRE) were screened for antibiotic susceptibility, , extended spectrum β-lactamases (ESBLs), metallo-β-lactamases (MBLs), and fosfomycin resistance genes using PCR and sequencing. The sequence types were identified by multilocus sequence typing (MLST). Plasmid profiles were determined by PCR based replicon typing (PBRT), and the plasmid sizes were confirmed by southern blotting.
RESULTS
The isolates showed high MIC and MIC for all antimicrobials, except tigecycline, meropenem, and colistin. The main Carbapenemase genes were (90.5%), (3.7%), (5.6%) and (14.5%). The found 36.7%, (3.7%) recorded in six isolates. PBRT revealed in on IncR, IncFII, and IncA/C. in on IncFII, whereas in noticed on IncHI2 plasmid. was recorded among IncFIIK, IncFII, and IncF in , and . Resistance genes ( , ) harboring plasmids are successfully trans-conjugant to . A high incidence of ST11 was observed in carbapenem resistant isolates. While in , multiple STs were identified. However, in ST23 was identified for the first time in Anhui Province. Among , ST270 detected carrying . Southern-hybridization confirmed the plasmid sizes 35-150kb.
CONCLUSION
This study indicates the co-carrying of and among clinical isolates, the prevalence of different Enterobacteriaceae STs is alarming, especially in . Holding such a resistance profile is a threat for humans and animals, which may be transferred between the strains through plasmid transfusion. Persistent control actions are immediately necessary to combat this hazard.
PubMed: 33854345
DOI: 10.2147/IDR.S303739 -
Scientific Reports Apr 2021Isolation of bacterial small colony variants (SCVs) from clinical specimens is not uncommon and can fundamentally change the outcome of the associated infections....
Isolation of bacterial small colony variants (SCVs) from clinical specimens is not uncommon and can fundamentally change the outcome of the associated infections. Bacterial SCVs often emerge with their normal colony phenotype (NCV) co-isolates in the same sample. The basis of SCV emergence in vivo is not well understood in Gram-negative bacteria. In this study, we interrogated the causal genetic lesions of SCV growth in three pairs of NCV and SCV co-isolates of Escherichia coli, Citrobacter freundii, and Enterobacter hormaechei. We confirmed SCV emergence was attributed to limited genomic mutations: 4 single nucleotide variants in the E. coli SCV, 5 in C. freundii, and 8 in E. hormaechei. In addition, a 10.2 kb chromosomal segment containing 11 genes was deleted in the E. hormaechei SCV isolate. Each SCV had at least one coding change in a gene associated with bacterial oxidative respiration and another involved in iron capture. Chemical and genetic rescue confirmed defects in heme biosynthesis for E. coli and C. freundii and lipoic acid biosynthesis in E. hormaachei were responsible for the SCV phenotype. Prototrophic growth in all 3 SCV Enterobacteriaceae species was unaffected under anaerobic culture conditions in vitro, illustrating how SCVs may persist in vivo.
Topics: Aerobiosis; Anaerobiosis; Biosynthetic Pathways; Child; Colony Count, Microbial; Drug Resistance, Bacterial; Enterobacteriaceae; Female; Gene Silencing; Genes, Bacterial; Genetic Variation; Heme; Humans; Infant; Iron; Kinetics; Male; Microbial Sensitivity Tests; Phenotype; Thioctic Acid; Whole Genome Sequencing
PubMed: 33811225
DOI: 10.1038/s41598-021-86764-4