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1.
J Med Microbiol ; 73(6)2024 Jun.
Article in English | MEDLINE | ID: mdl-38935081

ABSTRACT

Introduction. The absence of a gold-standard methodology for the microbiological diagnosis of urinary tract infections (UTI) has led to insufficient standardization of criteria for the interpretation of results and processing methods, particularly incubation time and culture media.Hypothesis. 48-hour incubation time period and use of blood agar enhances the sensitivity of microorganisms isolated significantly.Aim. To determine the sensitivity of blood agar and Brilliance UTI chromogenic agar, incubating for different periods (24-48 hours), for the detection of positive urine cultures.Methodoloy. Comparisons were made between all possible combinations of media and incubation times. As the gold-standard reference, we used the routine methodology of our laboratory, which involves prior screening with available clinical data, flow cytometry, sediment analysis and/or Gram staining. Screened samples were then cultured on blood agar and chromogenic agar and incubated for 48 hours. Also, based on the results of Gram staining, additional media were added in selected cases.Results. The most significant difference was found between chromogenic agar incubated for 24 hours and blood agar incubated for 48 hours, with the latter method allowing the recovery of 10.14 % more microorganisms (P < 0.0001). Furthermore, the value of performing Gram staining to guide processing was demonstrated, as it avoided the loss of at least 5.14 % of isolates.Conclusions. At least in urological and nephrological patients it is essential to include enriched culture media (blood agar) or to extend the incubation times due to the improvement of the diagnostic sensitivity of urine cultures. Gram staining also can help detect the presence of fastidious microorganisms or mixed infections, indicating whether rich and/or selective media should be included to enhance the diagnostic sensitivity of cultures. If this methodology is not followed, it should be noted that besides fastidious species, fastidious strains of Escherichia coli, Proteus mirabilis, Pseudomonas aerugniosa and Stenotrophomonas maltophilia will also be missed.


Subject(s)
Culture Media , Sensitivity and Specificity , Urinary Tract Infections , Urinary Tract Infections/diagnosis , Urinary Tract Infections/microbiology , Humans , Culture Media/chemistry , Time Factors , Bacteriological Techniques/methods , Bacteriological Techniques/standards , Bacteria/isolation & purification , Bacteria/classification , Bacteria/growth & development , Agar , Urine/microbiology
2.
J Hosp Infect ; 149: 98-103, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38685413

ABSTRACT

BACKGROUND: Many Gram-negative bacteria other than Pseudomonas aeruginosa have been implicated in waterborne outbreaks, but standardized laboratory detection methods for these organisms have not been established. AIM: This study aimed to establish laboratory testing methodologies for six waterborne pathogens: Acinetobacter spp., Burkholderia spp., Cupriavidus spp., Delftia acidovorans, Elizabethkingia spp. and Stenotrophomonas maltophilia. METHODS: Water samples were spiked by UK Health Security Agency laboratories and sent to the Glasgow Royal Infirmary laboratory for analysis. Water samples were spiked with either a pure culture of target organism or the target organism in water containing normal background flora, to ensure that the methodology could identify organisms from a mixed culture. Volumes of 100 mL were filtered under negative pressure on to culture media and incubated at 30 °C and 37 °C. The incubation time was 7 days, with plates read on days 2, 5 and 7. Further identification of colonies was undertaken using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). FINDINGS: Optimal recovery of organisms was obtained by culturing water samples on tryptic soy agar, chocolate bacitracin agar and pseudomonas selective agar. The optimal temperature for isolation was 30 °C. The optimal incubation time was 5 days, and MALDI-TOF MS identified all test species reliably. CONCLUSION: The methodology described was able to detect the six tested waterborne pathogens reliably, and can be utilized by laboratories involved in testing water samples during outbreak investigations.


Subject(s)
Hospitals , Water Microbiology , Humans , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Bacteriological Techniques/methods , Bacteriological Techniques/standards , Culture Media , Gram-Negative Bacteria/isolation & purification , Gram-Negative Bacteria/classification , Temperature , United Kingdom , Bacterial Load/methods
3.
J Microbiol Methods ; 211: 106778, 2023 08.
Article in English | MEDLINE | ID: mdl-37394181

ABSTRACT

In-house developed Bacillus anthracis-specific synthetic peptide-based latex agglutination test (LAT) assay was comparatively evaluated with World Organisation for Animal Health (WOAH)-recommended polymerase chain reaction (PCR)/real-time PCR (qPCR) methods for the screening of B. anthracis spores from the soil to provide a simple, rapid, and economical immunodiagnostic test for field application.


Subject(s)
Bacillus anthracis , Bacteriological Techniques , Latex Fixation Tests , Spores, Bacterial , Latex Fixation Tests/standards , Soil Microbiology , Bacillus anthracis/isolation & purification , Bacteriological Techniques/methods , Bacteriological Techniques/standards , Real-Time Polymerase Chain Reaction/standards , Spores, Bacterial/isolation & purification , Limit of Detection
4.
S Afr Med J ; 112(2): 13503, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-35139991

ABSTRACT

BACKGROUND: Bloodstream infections are an important cause of mortality in children. Blood cultures (BCs) remain the primary means of identifying organisms and their antibiotic susceptibility profiles. A shortcoming of BCs is that up to 56% of positive cultures will represent contaminants. Poor adherence to standard practices applicable to BC sampling could explain an unacceptable contamination rate. OBJECTIVES: To determine: (i) the BC contamination rate in the departments of paediatrics and child health at two tertiary hospitals in central South Africa; and (ii) BC sampling practices among paediatric clinicians. METHODS: The author determined the prevalence of BC contamination by analysis of laboratory data for the period 1 May - 27 August 2019, and assessed possible factors contributing to BC contamination by surveying paediatric medical staff with a self-administered BC practices questionnaire. RESULTS: Of the 244 BCs reviewed, 25.4% were positive. The most commonly isolated pathogens were coagulase-negative staphylococci (CoNS) (33.3%), Escherichia coli (22.2%), Enterococcus faecium (16.7%) and Acinetobacter baumannii (11.1%). In total, 15.2% of the BCs yielded contaminants and 2.9% had polymicrobial growth. The most common contaminant was CoNS. Approximately 68% of clinicians were not aware of BC sampling guidelines, and even among those who were aware of the guidelines, non-compliance was reported. CONCLUSIONS: The BC contamination rate was higher than internationally accepted rates. Educating clinicians on specific BC sampling guidelines is strongly recommended to decrease the high rate of contamination observed in this study.


Subject(s)
Bacteremia/diagnosis , Blood Culture/standards , Blood Specimen Collection/standards , Specimen Handling/standards , Bacteremia/microbiology , Bacteriological Techniques/standards , Guidelines as Topic , Humans , Pediatrics , Prevalence , South Africa , Surveys and Questionnaires , Tertiary Care Centers
5.
BMC Microbiol ; 22(1): 20, 2022 01 08.
Article in English | MEDLINE | ID: mdl-34996350

ABSTRACT

BACKGROUND: Legionella pneumophila is an opportunistic waterborne pathogen of significant public health problems, which can cause serious human respiratory diseases (Legionnaires' disease). Multiple cross displacement amplification (MCDA), a isothermal nucleic acid amplification technique, has been applied in the rapid detection of several bacterial agents. In this report, we developed a MCDA coupled with Nanoparticles-based Lateral Flow Biosensor (MCDA-LFB) for the rapid detection of L. pneumophila. RESULTS: A set of 10 primers based on the L. pneumophila specific mip gene to specifically identify 10 different target sequence regions of L. pneumophila was designed. The optimal time and temperature for amplification are 57 min and 65 °C. The limit of detection (LoD) is 10 fg in pure cultures of L. pneumophila. No cross-reaction was obtained and the specificity of MCDA-LFB assay was 100%. The whole process of the assay, including 20 min of DNA preparation, 35 min of L. pneumophila-MCDA reaction, and 2 min of sensor strip reaction, took a total of 57 min (less than 1 h). Among 88 specimens for clinical evaluation, 5 (5.68%) samples were L. pneumophila-positive by MCDA-LFB and traditional culture method, while 4(4.55%) samples were L. pneumophila-positive by PCR method targeting mip gene. Compared with culture method, the diagnostic accuracy of MCDA-LFB method was higher. CONCLUSIONS: In summary, the L. pneumophila-MCDA-LFB method we successfully developed is a simple, fast, reliable and sensitive diagnostic tool, which can be widely used in basic and clinical laboratories.


Subject(s)
Bacteriological Techniques/methods , Biosensing Techniques , Legionella pneumophila/isolation & purification , Nucleic Acid Amplification Techniques , Bacterial Proteins/genetics , Bacteriological Techniques/standards , Humans , Legionella pneumophila/genetics , Legionnaires' Disease/microbiology , Limit of Detection , Nanoparticles , Peptidylprolyl Isomerase/genetics , Sensitivity and Specificity , Time Factors , Water Microbiology
6.
BMC Microbiol ; 22(1): 31, 2022 01 20.
Article in English | MEDLINE | ID: mdl-35057744

ABSTRACT

BACKGROUND: Nasopharyngeal colonization is considered a necessary step in the initiation of pneumococcal diseases. Real time PCR (RT-PCR) is an alternative approach for the identification and quantification of pneumococci directly from samples. OBJECTIVES: To compare pneumococcal detection rates using culture-based method versus RT-PCR direct detection and to quantify pneumococcal colonization in two study cohorts (healthy children and hospitalized children with respiratory symptoms) using quantitation through RT-PCR. METHODOLOGY: A total of 101 nasopharyngeal swabs (NPS) from healthy children and 183 NPSs from hospitalized children with respiratory symptoms were included in the study. None of the children were vaccinated. All children were between 2 months to 2 years. In parallel to routine culture and identification, a RT-PCR assay targeting the lytA gene was done. RESULTS: Considering all 284 samples tested, colonization rate by conventional culture was 41.2% (n = 117) while positive colonization using RT-PCR was 43.7% (n = 124). The colonization rate detected by RT-PCR in the healthy cohort was 33.7% (n = 34) and it was 49.2% (n = 90) in the hospitalized cohort. It was 37.6% (n = 38) and 43.2% (n = 79) for the two cohorts by culture. The mean Cq value for the healthy cohort is 29.61 (SD 2.85) and 28.93 (SD 3.62) for the hospitalized cohort. With the standard curve obtained from amplifying a dilution series of control DNA, the mean amount of genomic DNA copy numbers detected in children with respiratory symptoms was log10 7.49 (SD 1.07) while it was log10 7.30 (SD 0.23) in healthy children and the difference was not statistically significant. CONCLUSIONS: The overall colonization rate was higher when detected using RT-PCR compared to culture. However, it was lower in the healthy group when detected with RT-PCR compared to culture. Even though there was a higher detection of pneumococcal colonization density in children with respiratory symptoms, this was not significantly higher unlike many previous studies. Therefore, the use of RT-PCR to detect pneumococcal colonization needs further evaluation with careful analysis of interpretation and confounders.


Subject(s)
Bacteriological Techniques/standards , Hospitalization/statistics & numerical data , Pneumococcal Infections/microbiology , Real-Time Polymerase Chain Reaction/standards , Streptococcus pneumoniae/growth & development , Streptococcus pneumoniae/genetics , Child, Preschool , Cohort Studies , Healthy Volunteers/statistics & numerical data , Humans , Infant , Nasopharynx/microbiology , Real-Time Polymerase Chain Reaction/methods , Respiratory Tract Infections/microbiology , Streptococcus pneumoniae/isolation & purification
7.
Diagn Microbiol Infect Dis ; 102(2): 115593, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34852987

ABSTRACT

We evaluated the diagnostic performances of 2 media (BCYE, MWY) on 951 Legionella-positive hospital water samples. MWY allowed detecting Legionella in 89.2% of samples, but in 10.8% (103/951) Legionella was found on BCYE plates only. In samples where Legionella was isolated with other microorganisms (663/951), MWY was essential to detect the majority of positive samples (349/663, 52.6%), as fewer plates resulted unreadable; however, in those containing Legionella only, a higher frequency of positive samples was recorded with BCYE (94.8%, 273/288) compared to MWY (85.1%, 245/288). Considering the 484 concordant positive samples, overall Legionella counts were significantly higher on BCYE (P = 0.0029), with 47% of samples showing higher counts on BCYE compared to MWY plates. Furthermore, discordant samples (positive on only one medium) showed different relative proportions between Legionella pneumophila and non-pneumophila, the latter being found more frequently on BCYE only (P = 0.0296).Our findings confirm the appropriateness of the ISO 11731:2017 update.


Subject(s)
Bacteriological Techniques/standards , Culture Media/standards , Environmental Monitoring/standards , Guidelines as Topic , Legionella/isolation & purification , Water Microbiology/standards , Humans
9.
Afr Health Sci ; 21(2): 628-632, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34795716

ABSTRACT

BACKGROUND: Tuberculosis (TB) sputum culture contaminants make it difficult to obtain pure TB isolates.We aimed to study and identify persistent TB sputum culture contaminants post the standard laboratory pre-culture sample decontamination techniques. METHODS: This was a longitudinal study of TB sputum culture contamination for a cohort of TB patients on standard treatment at: baseline, during TB treatment and post TB treatment. Sputum samples were decontaminated with 1.5%NaOH and neutralized using 6.8 Phosphate buffer solution.Sputum was then inoculated into MGIT (mycobactrial growth indicator tube) supplemented with 0.8ml PANTA. A drop of each positive MGIT culture was sub cultured onto blood agar and incubated for 48 hours at 35 -37OC.Any growth was identified using growth characteristics and colony morphology. RESULTS: From October 2017 through May 2019;we collected 8645 sputum samples of which 8624(99.8%) were eligible and inoculated into MGIT where 2444(28.3%)samples were TB culture positive and 255(10.4%)were positive for contaminants: 237 none-tuberculosis bacteria, 12 fungi and 6 mixed(none-tuberculous bacteria+fungi). There was no statistically significant difference between none tuberculosis bacteria and fungi in the treatment (OR=1.4,95%CI:0.26-7.47,p=0.690) and the post treatment TB phases(OR=2.02,95%CI:0.38-10.79,p=0.411)Vs baseline. CONCLUSION: None-tuberculous bacteria and fungi dominate the plethora of TB sputum culture contamination and persist beyond the standard laboratory pre-culture decontamination algorithm.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteriological Techniques/methods , Sputum/microbiology , Tuberculosis/diagnosis , Amphotericin B/pharmacology , Azlocillin/pharmacology , Bacteria/isolation & purification , Bacteriological Techniques/standards , Fungi/isolation & purification , Humans , Longitudinal Studies , Mycobacterium tuberculosis/growth & development , Nalidixic Acid/pharmacology , Polymyxin B/pharmacology , Trimethoprim/pharmacology
10.
Braz J Microbiol ; 52(4): 2057-2062, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34392499

ABSTRACT

Accurate detection of Helicobacter pylori infection and determination of antibiotics have significant meaning in clinical practice. The detection methods can be categorized into two types, invasive and non-invasive, but nowadays we use the urease breath test most frequently which is non-invasive. However, many developing countries cannot meet the requirements for having specialized equipment and they lack trained personnel. Also, for the children, it is difficult to make them cooperate for the test. Methods that detect Helicobacter pylori from stool sample can be a promising alternative for detection used in children and mass screening. Stool antigen tests have several advantages such as rapidity, simplicity, and cheapness, though their results may be influenced by the heterogenicity of antigens, the nature of biochemical techniques, and the amount of antigen presented in the stool. PCR-based methods can specifically detect Helicobacter pylori infection and antibiotic resistance by targeting specific gene sequence, but they also are limited by the requirements of facilities and experts, the existence of inhibitory substance, and interference from the dead bacteria. Some novel methods also deserve our attention. Here we summarized the results of researches about methods using stool sample and we hope our work can help clinicians choose the appropriate test in clinical practice.


Subject(s)
Bacteriological Techniques , Feces , Helicobacter Infections , Helicobacter pylori , Bacteriological Techniques/methods , Bacteriological Techniques/standards , Bacteriological Techniques/trends , Feces/microbiology , Helicobacter Infections/diagnosis , Helicobacter pylori/genetics , Helicobacter pylori/isolation & purification , Humans , Sensitivity and Specificity
11.
BMC Microbiol ; 21(1): 213, 2021 07 16.
Article in English | MEDLINE | ID: mdl-34266382

ABSTRACT

BACKGROUND: Burkholderia pseudomallei is the bacterial causative agent of melioidosis, a difficult disease to diagnose clinically with high mortality if not appropriately treated. Definitive diagnosis requires isolation and identification of the organism. With the increased adoption of MALDI-TOF MS for the identification of bacteria, we established a method for rapid identification of B. pseudomallei using the Vitek MS, a system that does not currently have B. pseudomallei in its in-vitro diagnostic database. RESULTS: A routine direct spotting method was employed to create spectra and SuperSpectra. An initial B. pseudomallei SuperSpectrum was created at Shoklo Malaria Research Unit (SMRU) from 17 reference isolates (46 spectra). When tested, this initial SMRU SuperSpectrum was able to identify 98.2 % (54/55) of Asian isolates, but just 46.7 % (35/75) of Australian isolates. Using spectra (430) from different reference and clinical isolates, two additional SMRU SuperSpectra were created. Using the combination of all SMRU SuperSpectra with seven existing SuperSpectra from Townsville, Australia 119 (100 %) Asian isolates and 31 (100 %) Australian isolates were correctly identified. In addition, no misidentifications were obtained when using these 11 SuperSpectra when tested with 34 isolates of other bacteria including the closely related species Burkholderia thailandensis and Burkholderia cepacia. CONCLUSIONS: This study has established a method for identification of B. pseudomallei using Vitek MS, and highlights the impact of geographical differences between strains for identification using this technique.


Subject(s)
Burkholderia pseudomallei/chemistry , Burkholderia pseudomallei/isolation & purification , Melioidosis/diagnosis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Bacteriological Techniques/instrumentation , Bacteriological Techniques/standards , Melioidosis/microbiology , Reproducibility of Results , Species Specificity
12.
N Z Med J ; 134(1539): 33-43, 2021 07 30.
Article in English | MEDLINE | ID: mdl-34320613

ABSTRACT

AIMS: This study describes 47 presentations of suspected leptospirosis in general practice in New Zealand. Our primary aim was to assess the laboratory diagnosis of leptospirosis in these patients, by comparing polymerase chain reaction (PCR) tests, microscopic agglutination test (MAT) and culture results. METHODS: Patients suspected of leptospirosis were recruited from general practices in the Waikato (n=17) and Wairoa (n=30) between August 2011 and June 2015. Blood and urine samples were tested for leptospirosis at two diagnostic laboratories and one research laboratory using PCR tests, MAT and culture. RESULTS: Forty-seven patients were recruited for this study: 37 during the acute phase of the illness (within 10 days of symptom onset) and 10 after the acute phase. Eleven of the acute phase patients (11/37, 30%) and two of the later phase patients (2/10, 20%) returned positive leptospirosis test results. The 11 acute phase leptospirosis positive patients had the following positive diagnostic tests: PCR and paired MAT (+/- blood culture) (n=3), PCR only (+/- blood culture) (n=4), paired MAT only (n=3) and blood culture only (n=1). Urine PCR (performed only on Wairoa patients) was the only positive test for two of these patients. CONCLUSION: About a quarter of farm workers and meat workers presenting to general practice with flu-like symptoms will have leptospirosis, but they will not be diagnosed unless appropriately tested, and then they may only test positive for some of the tests available. To increase the likelihood of making a diagnosis, clinicians should order multiple laboratory tests, including blood and urine PCR and a paired MAT.


Subject(s)
Bacteriological Techniques/methods , Bacteriological Techniques/standards , Leptospirosis/diagnosis , Primary Health Care , Adolescent , Adult , Aged , Child , Humans , Male , Middle Aged , New Zealand , Young Adult
13.
Arch Microbiol ; 203(7): 4737-4742, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34184097

ABSTRACT

In vivo bioluminescence imaging (BLI) offers a unique opportunity to analyze ongoing bacterial infections qualitatively and quantitatively in intact animals over time, leading to a reduction in the number of animals needed for a study. Since accurate determination of the bacterial burden plays an essential role in microbiological research, the present study aimed to evaluate the ability to quantify bacteria by non-invasive BLI technique in comparison to standard spread plate method and reverse transcription quantitative PCR (RT-qPCR). For this purpose, BALB/c mice were intranasally infected with 1 × 105 CFU of bioluminescent Streptococcus pneumoniae A66.1. At day 1 post-infection, the presence of S. pneumoniae in lungs was demonstrated by spread plate method and RT-qPCR, but not by in vivo BLI. However, on the second day p.i., the bioluminescent signal was already detectable, and the photon flux values positively correlated with CFU counts and RT-qPCR data within days 2-6. Though in vivo BLI is valuable research tool allowing the continuous monitoring and quantification of pneumococcal infection in living mice, it should be kept in mind that early in the infection, depending on the infective dose, the bioluminescent signal may be below the detection limit.


Subject(s)
Bacterial Physiological Phenomena , Animals , Bacteria/genetics , Bacteriological Techniques/standards , Luminescent Measurements/standards , Mice , Mice, Inbred BALB C , Reverse Transcriptase Polymerase Chain Reaction/standards
14.
J Orthop Surg Res ; 16(1): 310, 2021 May 13.
Article in English | MEDLINE | ID: mdl-33985549

ABSTRACT

BACKGROUND: In fracture-related infections (FRI), both the diagnosis of the infection and the identification of the causative pathogen are crucial to optimize treatment outcomes. Sonication has been successfully used for periprosthetic joint infections (PJI); however, its role in FRI remains unknown. Our aim was to determine the diagnostic accuracy (sensitivity, specificity) of sonicate fluid culture (SFC). The primary objective was to compare SFC with peri-implant tissue culture (PTC) overall and among subgroups using the consensus definition by Metsemakers et al. The secondary objective was to determine the yield of SFC in possible fracture-related infections (PFRI). METHODS: From March 2017 to May 2019, 230 cases of retrieved implants were retrospectively reviewed. To perform sonication, explants were placed in sterile polypropylene jars intraoperatively. After treatment in an ultrasonic bath (Bandelin, Berlin, Germany), sonicate fluid was incubated into blood culture bottles, and conventional culturing was eventually performed. Sensitivity and specificity were determined using two-by-two contingency tables. McNemar's test was used to compare proportions among paired samples while Fisher's exact test was used for comparison between categorical variables. RESULTS: Of the 230 cases, 107 were identified as FRI, whereas 123 were aseptic revision cases (ARC). Of the latter, 105 were labeled as PFRI. Sensitivity of SFC was higher in comparison with PTC, although this did not reach statistical significance (90.7% vs. 84.1%; p = .065). The specificity of SFC was significantly lower than that of PTC (73.2% vs. 88.6%; p = .003). In PFRI, SFC yielded significantly more positive results than PTC (33/105 vs. 14/105; p = .003). Overall, 142 pathogens were identified by SFC, whereas 131 pathogens were found by PTC. CONCLUSIONS: We found that sonication of fracture fixation devices may be a useful adjunct in FRI, especially in "low-grade" infections lacking confirmatory clinical criteria. Standardized diagnostic protocols are warranted in order to further optimize the diagnostic accuracy.


Subject(s)
Bacteriological Techniques/standards , Equipment Contamination , Fractures, Bone/surgery , Internal Fixators/microbiology , Prosthesis-Related Infections/diagnosis , Prosthesis-Related Infections/microbiology , Sonication/standards , Adolescent , Adult , Aged , Aged, 80 and over , Bacteriological Techniques/methods , Child , Device Removal , Female , Humans , Male , Middle Aged , Retrospective Studies , Sonication/methods , Young Adult
15.
BMC Microbiol ; 21(1): 100, 2021 03 31.
Article in English | MEDLINE | ID: mdl-33789573

ABSTRACT

BACKGROUND: 16S rRNA gene sequencing is currently the most common way of determining the composition of microbiota. This technique has enabled many new discoveries to be made regarding the relevance of microbiota to the health and disease of the host. However, compared to other diagnostic techniques, 16S rRNA gene sequencing is fairly costly and labor intensive, leaving room for other techniques to improve on these aspects. RESULTS: The current study aimed to compare the output of 16S rRNA gene sequencing to the output of the quick IS-pro analysis, using vaginal swab samples from 297 women of reproductive age. 16S rRNA gene sequencing and IS-pro analyses yielded very similar vaginal microbiome profiles, with a median Pearson's R2 of 0.97, indicating a high level of similarity between both techniques. CONCLUSIONS: We conclude that the results of 16S rRNA gene sequencing and IS-pro are highly comparable and that both can be used to accurately determine the vaginal microbiota composition, with the IS-pro analysis having the benefit of rapidity.


Subject(s)
Bacteria/genetics , Bacteriological Techniques/standards , Microbiota/genetics , Vagina/microbiology , Adult , Bacteriological Techniques/economics , Electrophoresis, Capillary/economics , Electrophoresis, Capillary/standards , Female , Humans , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA/economics , Sequence Analysis, DNA/standards
16.
Clin J Am Soc Nephrol ; 16(2): 233-240, 2021 02 08.
Article in English | MEDLINE | ID: mdl-33462084

ABSTRACT

BACKGROUND AND OBJECTIVES: International guidelines suggest a target culture-negative peritonitis rate of <15% among patients receiving long-term peritoneal dialysis. Through a pediatric multicenter dialysis collaborative, we identified variable rates of culture-negative peritonitis among participating centers. We sought to evaluate whether specific practices are associated with the variability in culture-negative rates between low- and high-culture-negative rate centers. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Thirty-two pediatric dialysis centers within the Standardizing Care to Improve Outcomes in Pediatric End Stage Renal Disease (SCOPE) collaborative contributed prospective peritonitis data between October 1, 2011 and March 30, 2017. Clinical practice and patient characteristics were compared between centers with a ≤20% rate of culture-negative peritonitis (low-rate centers) and centers with a rate >20% (high-rate centers). In addition, centers completed a survey focused on center-specific peritoneal dialysis effluent culture techniques. RESULTS: During the 5.5 years of observation, 1113 patients had 1301 catheters placed, totaling 19,025 patient months. There were 620 episodes of peritonitis in 378 patients with 411 catheters; cultures were negative in 165 (27%) peritonitis episodes from 125 (33%) patients and 128 (31%) catheters. Low-rate centers more frequently placed catheters with a downward-facing exit site and two cuffs (P<0.001), whereas high-rate centers had more patients perform dialysis themselves without the assistance of an adult care provider (P<0.001). The survey demonstrated that peritoneal dialysis effluent culture techniques were highly variable across centers. No consistent practice or technique helped to differentiate low- and high-rate centers. CONCLUSIONS: Culture-negative peritonitis is a frequent complication of maintenance peritoneal dialysis in children. Despite published recommendations for dialysis effluent collection and culture methods, great variability in culture techniques and procedures exists among individual dialysis programs and respective laboratory processes.


Subject(s)
Ambulatory Care Facilities/statistics & numerical data , Peritoneal Dialysis/adverse effects , Peritoneal Dialysis/standards , Peritonitis/microbiology , Specimen Handling/standards , Adolescent , Bacteriological Techniques/standards , Catheterization/adverse effects , Catheters, Indwelling/adverse effects , Child , Child, Preschool , Clinical Laboratory Techniques , Dialysis Solutions , Female , Humans , Infant , Male , Prospective Studies , Self Care/statistics & numerical data , United States
17.
Bone Joint J ; 103-B(1): 39-45, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33380187

ABSTRACT

AIMS: Metagenomic next-generation sequencing (mNGS) is useful in the diagnosis of infectious disease. However, while it is highly sensitive at identifying bacteria, it does not provide information on the sensitivity of the organisms to antibiotics. The purpose of this study was to determine whether the results of mNGS can be used to guide optimization of culture methods to improve the sensitivity of culture from intraoperative samples. METHODS: Between July 2014 and October 2019, patients with suspected joint infection (JI) from whom synovial fluid (SF) was obtained preoperatively were enrolled. Preoperative aspirated SF was analyzed by conventional microbial culture and mNGS. In addition to samples taken for conventional microbial culture, some samples were taken for intraoperative culture to optimize the culture method according to the preoperative mNGS results. The demographic characteristics, medical history, laboratory examination, mNGS, and culture results of the patients were recorded, and the possibility of the optimized culture methods improving diagnostic efficiency was evaluated. RESULTS: A total of 56 cases were included in this study. There were 35 cases of JI and 21 cases of non-joint infection (NJI). The sensitivity, specificity, and accuracy of intraoperative microbial culture after optimization of the culture method were 94.29%, 76.19%, and 87.5%, respectively, while those of the conventional microbial culture method were 60%, 80.95%, and 67.86%, respectively. CONCLUSION: Preoperative aspirated SF detected via mNGS can provide more aetiological information than preoperative culture, which can guide the optimization and improve the sensitivity of intraoperative culture. Cite this article: Bone Joint J 2021;103-B(1):39-45.


Subject(s)
Arthritis, Infectious/diagnosis , Bacteriological Techniques/standards , High-Throughput Nucleotide Sequencing , Metagenomics , Prosthesis-Related Infections/diagnosis , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Arthritis, Infectious/drug therapy , Arthritis, Infectious/microbiology , Female , Humans , Male , Middle Aged , Prosthesis-Related Infections/drug therapy , Prosthesis-Related Infections/microbiology , Sensitivity and Specificity
18.
Diagn Microbiol Infect Dis ; 99(2): 115243, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33130506

ABSTRACT

Mycobacterium tuberculosis (MTB) is commonly diagnosed via the GeneXpert MTB/RIF assay. The cycle threshold (Ct) value of probe A from this assay produced a fluorescence signal upon Mycobacterium intracellulare detection. No other nontuberculous mycobacteria (NTM) exhibited positive probe signals. Using a confirmed mycobacterial culture as a standard, probe A of the assay exhibited 84% sensitivity (95% confidence interval [CI]: 71%-97%) and 50% specificity (95% CI: 37%-63%) for clinical samples. For M. intracellulare strains, probe A exhibited 90% sensitivity (95% CI: 80%-100%) and 50% specificity (95% CI: 37%-63%). The identity of the amino acid sequence and 81-bp core region of rpoB from MTB and NTM suggested that the highly conserved property might be associated with a mismatch between the probes and the chromosomal DNA target. Probe A yielded a positive signal upon M. intracellulare detection; thus, probe A may help diagnose M. intracellular infections.


Subject(s)
Bacteriological Techniques , Molecular Diagnostic Techniques , Mycobacterium avium Complex/isolation & purification , Mycobacterium avium-intracellulare Infection/diagnosis , Bacterial Proteins/genetics , Bacteriological Techniques/standards , Drug Resistance, Bacterial/genetics , Humans , Mycobacterium avium Complex/genetics , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/isolation & purification , Nontuberculous Mycobacteria/genetics , Nontuberculous Mycobacteria/isolation & purification , Rifampin/pharmacology , Sensitivity and Specificity , Sequence Analysis
19.
Diagn Microbiol Infect Dis ; 99(2): 115236, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33130507

ABSTRACT

Lower respiratory tract infections are important causes of morbidity and mortality. The global increase in antimicrobial resistance necessitates rapid diagnostic assays. The BioFire FilmArray Pneumonia plus (FAPP) panel is a Food and Drug Administration-approved multiplex polymerase chain reaction assay that detects the most important etiological agents of pneumonia and associated antibiotic resistance genes, in approximately 1 hour. This study assessed the diagnostic performance of this assay by comparing it to conventional culture methods in the analysis of 59 lower respiratory tract specimens. The sensitivity and specificity of the FAPP panel for bacterial detection were 92.0% (95% confidence interval [CI], 80.8% to 97.8%) and 93.8% (95% CI, 91.1% to 95.3%) respectively. For detecting antibiotic resistance, the positive- and negative percent agreement were 100% (95% CI, 81.5% to 100.0%) and 98.5% (95% CI, 216 96.7% to 99.4%) respectively. The FAPP panel was found to be highly accurate in evaluating tracheal aspirate specimens from hospitalized patients.


Subject(s)
Bacteria/isolation & purification , Bacteriological Techniques , Molecular Diagnostic Techniques , Respiratory Tract Infections/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Bacteria/classification , Bacteria/genetics , Bacteriological Techniques/standards , Bronchoalveolar Lavage Fluid/microbiology , Child , Child, Preschool , Cross-Sectional Studies , Drug Resistance, Bacterial/genetics , Female , Humans , Infant , Male , Middle Aged , Multiplex Polymerase Chain Reaction , Pneumonia, Bacterial/diagnosis , Pneumonia, Bacterial/microbiology , Prospective Studies , Sensitivity and Specificity , South Africa , Trachea/microbiology , Young Adult
20.
Western Pac Surveill Response J ; 11(1): 41-46, 2020.
Article in English | MEDLINE | ID: mdl-32963890

ABSTRACT

PROBLEM: Emerging bacterial antimicrobial (antibiotic) resistance (AMR) is a global threat to human health. However, most lower income countries do not have microbiological diagnostic testing for prompt, reliable confirmation of bloodstream infection and identification of AMR. CONTEXT: Clinicians in Pacific island nations are increasingly challenged by patients who have infection due to antimicrobial-resistant bacteria. Treatment of infection remains empirical because of a lack of diagnostic testing capacity and may follow guidelines that were formulated without reference to local measures of AMR prevalence. There is limited understanding among clinicians of microbiology testing and test interpretation. ACTION: Examine the lessons learnt from pilot laboratory development programmes in two Pacific island nations that focused on establishing standard procedures for micrological diagnostics and antimicrobial susceptibility testing (AST) and on improving the training of clinicians to increase their use of laboratory services. OUTCOME: The pilot programmes addressed a range of logistical difficulties and evaluated two blood culture systems. They also examined and improved internal QC implementation and evaluated the prevalence of AMR. DISCUSSION: Continued development of microbiological diagnostic capability in the Pacific region is paramount. Pacific Island nations need to develop the capability of at least one central laboratory to culture AMR pathogens and subject them to quality-controlled AST or arrange for suitable referral to a nearby country. DISCUSSION: This study demonstrated a persistently high prevalence of three major bacterial STIs across four countries in WHO's Western Pacific Region during nearly two decades. Further strengthening of strategies to control and prevent STIs is warranted.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteriological Techniques/standards , Drug Resistance, Bacterial , Microbial Sensitivity Tests/standards , Molecular Diagnostic Techniques/standards , Humans , Pacific Islands , Pilot Projects , Quality Control
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