-
Infection and Drug Resistance 2023Due to similar colony morphology among viridans group streptococci (VGS), the differentiation of VGS species remains difficult in routine clinical microbiology....
Performance of Two Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS) Systems for Identification of the Viridans Group Streptococci.
BACKGROUND
Due to similar colony morphology among viridans group streptococci (VGS), the differentiation of VGS species remains difficult in routine clinical microbiology. Recently, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been described as a fast method for identifying various bacteria at species level, and also for the VGS strains.
METHODS
A total of 277 VGS isolates were identified with the two MALDI-TOF MS systems (VITEK MS and Bruker Biotyper). The and gene sequencing was used as the reference identification method for comparison.
RESULTS
Based on and gene sequencing, 84 isolates were and 193 strains were other VGS isolates including group (n=91, 47.2%), group (n=80, 41.5%), group (n=11, 5.7%), group (n=10, 5.2%), and group (n=1, 0.5%). VITEK MS and Bruker Biotyper accurately identified 94.6% and 89.9% of all VGS isolates, respectively. VITEK MS showed better identification results than Bruker Biotyper for group including group, but for other VGS isolates, two MALDI-TOF MS systems showed comparable identification performance. However, VITEK MS was able to identify to the subspecies level with high-confidence ( ssp. ), while the Bruker Biotyper system could not. While Bruker Biotyper system could be able to correctly differentiate the subspecies of from , VITEK MS poorly identify.
CONCLUSION
This study demonstrated that two MALDI-TOF MS systems allowed discrimination for most VGS isolates with different identification performance, but Bruker Biotyper could produce more misidentifications and VITEK MS system. It is crucial to be familiar with the performance of MALDI-TOF MS systems used in clinical microbiology.
PubMed: 37193297
DOI: 10.2147/IDR.S407667 -
Arab Journal of Gastroenterology : the... Aug 2023Colorectal cancer (CRC) is the second most common cancer in Malaysia and mostly detected at advanced stages due to lack of awareness of CRC symptoms and signs. CRC...
BACKGROUND AND STUDY AIMS
Colorectal cancer (CRC) is the second most common cancer in Malaysia and mostly detected at advanced stages due to lack of awareness of CRC symptoms and signs. CRC pathogenesis is multifactorial, and there is ambiguous evidence on association of Streptococcus gallolyticus infection with CRC that needs further attention. Thus, a case-control study was conducted to determine whether S. gallolyticus infection is a predictor for CRC occurrence among patients attending Sultan Ahmad Shah Medical Centre@IIUM (SASMEC@IIUM).
PATIENTS AND METHODS
A total of 33 stool samples from patients diagnosed with CRC and 80 from patients without CRC attending surgical clinic of SASMEC@IIUM were collected and analyzed with iFOBT test and PCR assay to detect S. gallolyticus.
RESULTS
In this study, the proportion of S. gallolyticus infection was higher among patients with CRC (48.5%) compared with the control group (20%). Univariate analysis shows that occult blood in stool, S. gallolyticus infection and family history were significantly associated with the development of CRC (P < 0.05). Using the multivariate logistic regression model, positive stool PCR for S. gallolyticus had the lowest relative standard error and almost five times the odds of developing CRC after adjusting other factors (adjusted odds ratio = 4.7, 95% confidence interval = 1.7-12.6, relative standard error = 59.6%).
CONCLUSION
This finding suggests that S. gallolyticus infection was the strongest predictor of CRC's development in our study and potentially serves as a predictive marker for early detection of disease progression.
Topics: Humans; Case-Control Studies; Colorectal Neoplasms; Streptococcal Infections; Nucleic Acid Amplification Techniques; Streptococcus gallolyticus
PubMed: 37156704
DOI: 10.1016/j.ajg.2023.02.002 -
European Journal of Clinical... Jul 2023Whether cirrhotic patients with Streptococcus bovis bacteremia have an increased risk of colorectal neoplasm is uncertain. A multicentric retrospective cohort study was...
Whether cirrhotic patients with Streptococcus bovis bacteremia have an increased risk of colorectal neoplasm is uncertain. A multicentric retrospective cohort study was conducted investigating associations between S. bovis biotype and species, cirrhosis, and colorectal neoplasm. Out of 779 patients with S. bovis bacteremia, 69 (8.7%) had cirrhosis. No differences were found in the prevalence of colorectal neoplasm between cirrhotic and non-cirrhotic patients undergoing colonoscopy. Among cirrhotic patients, prevalence of colorectal neoplasms was higher in S. bovis biotype I (S. gallolyticus) bacteremia (80%) than in S. bovis biotype II (33.3%; p < 0.007). In conclusion, risk of colorectal neoplasm is high among cirrhotic patients with S. gallolyticus bacteremia.
Topics: Humans; Streptococcus bovis; Retrospective Studies; Colonic Neoplasms; Colorectal Neoplasms; Liver Cirrhosis; Bacteremia; Streptococcal Infections
PubMed: 37145237
DOI: 10.1007/s10096-023-04618-5 -
Scientific Reports Apr 2023Streptococcus gallolyticus subspecies gallolyticus (Sgg) is known to be strongly associated with colorectal cancer (CRC). Recent functional studies further demonstrated...
Streptococcus gallolyticus subspecies gallolyticus (Sgg) is known to be strongly associated with colorectal cancer (CRC). Recent functional studies further demonstrated that Sgg actively stimulates CRC cell proliferation and promotes the development of colon tumors. However, the Sgg factors important for the pro-proliferative and pro-tumor activities of Sgg remain unclear. Here, we identified a chromosomal locus in Sgg strain TX20005. Deletion of this locus significantly reduced Sgg adherence to CRC cells and abrogated the ability of Sgg to stimulate CRC cell proliferation. Thus, we designate this locus as the Sgg pathogenicity-associated region (SPAR). More importantly, we found that SPAR is important for Sgg pathogenicity in vivo. In a gut colonization model, mice exposed to the SPAR deletion mutant showed significantly reduced Sgg load in the colonic tissues and fecal materials, suggesting that SPAR contributes to the colonization capacity of Sgg. In a mouse model of CRC, deletion of SPAR abolished the ability of Sgg to promote the development of colon tumors growth. Taken together, these results highlight SPAR as a critical pathogenicity determinant of Sgg.
Topics: Animals; Mice; Streptococcus gallolyticus subspecies gallolyticus; Virulence; Colorectal Neoplasms; Colonic Neoplasms; Streptococcal Infections
PubMed: 37072463
DOI: 10.1038/s41598-023-33178-z -
Infection Oct 2023Streptococcal bloodstream infections (BSIs) are common, yet prognostic factors are poorly investigated. We aimed to investigate the mortality according to streptococcal...
PURPOSE
Streptococcal bloodstream infections (BSIs) are common, yet prognostic factors are poorly investigated. We aimed to investigate the mortality according to streptococcal species and seasonal variation.
METHODS
Patients with streptococcal BSIs from 2008 to 2017 in the Capital Region of Denmark were investigated, and data were crosslinked with nationwide registers for the identification of comorbidities. A multivariable logistic regression analysis was performed to assess mortality according to streptococcal species and season of infection.
RESULTS
Among 6095 patients with a streptococcal BSI (mean age 68.1 years), the 30-day mortality was 16.1% and the one-year mortality was 31.5%. With S. pneumoniae as a reference, S. vestibularis was associated with a higher adjusted mortality both within 30 days (odds ratio (OR) 2.89 [95% confidence interval (CI) 1.20-6.95]) and one year (OR 4.09 [95% CI 1.70-9.48]). One-year mortality was also higher in S. thermophilus, S. constellatus, S. parasanguinis, S. salivarius, S. anginosus, and S. mitis/oralis. However, S. mutans was associated with a lower one-year mortality OR 0.44 [95% CI 0.20-0.97], while S. gallolyticus was associated with both a lower 30-day (OR 0.42 [95% CI 0.26-0.67]) and one-year mortality (OR 0.66 [95% CI 0.48-0.93]). Furthermore, with infection in the summer as a reference, patients infected in the winter and autumn had a higher association with 30-day mortality.
CONCLUSIONS
The mortality in patients with streptococcal BSI was associated with streptococcal species. Further, patients with streptococcal BSIs infected in the autumn and winter had a higher risk of death within 30 days, compared with patients infected in the summer.
Topics: Humans; Aged; Prognosis; Streptococcus; Streptococcal Infections; Streptococcus pneumoniae; Sepsis; Bacteremia
PubMed: 36959526
DOI: 10.1007/s15010-023-02025-8 -
European Journal of Clinical... May 2023
Topics: Animals; Humans; Strongyloides stercoralis; Strongyloidiasis; Lupus Erythematosus, Systemic; Streptococcal Infections; Meningitis, Bacterial; Streptococcus gallolyticus
PubMed: 36959358
DOI: 10.1007/s10096-023-04589-7 -
Microbiology Spectrum Mar 2023Streptococcus gallolyticus subsp. () is an opportunistic gut pathogen associated with colorectal cancer. We previously showed that colonization of the murine colon by...
Streptococcus gallolyticus subsp. () is an opportunistic gut pathogen associated with colorectal cancer. We previously showed that colonization of the murine colon by in tumoral conditions was strongly enhanced by the production of gallocin A, a two-peptide bacteriocin. Here, we aimed to characterize the mechanisms of its action and resistance. Using a genetic approach, we demonstrated that gallocin A is composed of two peptides, GllA1 and GllA2, which are inactive alone and act together to kill "target" bacteria. We showed that gallocin A can kill phylogenetically close relatives of the pathogen. Importantly, we demonstrated that gallocin A peptides can insert themselves into membranes and permeabilize lipid bilayer vesicles. Next, we showed that the third gene of the gallocin A operon, , is necessary and sufficient to confer immunity to gallocin A. Structural modeling of GllA1 and GllA2 mature peptides suggested that both peptides form alpha-helical hairpins stabilized by intramolecular disulfide bridges. The presence of a disulfide bond in GllA1 and GllA2 was confirmed experimentally. Addition of disulfide-reducing agents abrogated gallocin A activity. Likewise, deletion of a gene encoding a surface protein with a thioredoxin-like domain impaired the ability of gallocin A to kill Enterococcus faecalis. Structural modeling of GIP revealed a hairpin-like structure strongly resembling those of the GllA1 and GllA2 mature peptides, suggesting a mechanism of immunity by competition with GllA1/2. Finally, identification of other class IIb bacteriocins exhibiting a similar alpha-helical hairpin fold stabilized with an intramolecular disulfide bridge suggests the existence of a new subclass of class IIb bacteriocins. Streptococcus gallolyticus subsp. (), previously named Streptococcus bovis biotype I, is an opportunistic pathogen responsible for invasive infections (septicemia, endocarditis) in elderly people and is often associated with colon tumors. is one of the first bacteria to be associated with the occurrence of colorectal cancer in humans. Previously, we showed that tumor-associated conditions in the colon provide with an ideal environment to proliferate at the expense of phylogenetically and metabolically closely related commensal bacteria such as enterococci (1). takes advantage of CRC-associated conditions to outcompete and substitute commensal members of the gut microbiota using a specific bacteriocin named gallocin, recently renamed gallocin A following the discovery of gallocin D in a peculiar isolate. Here, we showed that gallocin A is a two-peptide bacteriocin and that both GllA1 and GllA2 peptides are required for antimicrobial activity. Gallocin A was shown to permeabilize bacterial membranes and kill phylogenetically closely related bacteria such as most streptococci, lactococci, and enterococci, probably through membrane pore formation. GllA1 and GllA2 secreted peptides are unusually long (42 and 60 amino acids long) and have very few charged amino acids compared to well-known class IIb bacteriocins. modeling revealed that both GllA1 and GllA2 exhibit a similar hairpin-like conformation stabilized by an intramolecular disulfide bond. We also showed that the GIP immunity peptide forms a hairpin-like structure similar to GllA1/GllA2. Thus, we hypothesize that GIP blocks the formation of the GllA1/GllA2 complex by interacting with GllA1 or GllA2. Gallocin A may constitute the first class IIb bacteriocin which displays disulfide bridges important for its structure and activity and might be the founding member of a subtype of class IIb bacteriocins.
PubMed: 36951576
DOI: 10.1128/spectrum.05085-22 -
Microbiology Resource Announcements Apr 2023We assembled a complete genome sequence of Streptococcus gallolyticus strain XH2168 by combining the sequencing results from both the Illumina and Oxford Nanopore...
We assembled a complete genome sequence of Streptococcus gallolyticus strain XH2168 by combining the sequencing results from both the Illumina and Oxford Nanopore platforms. The assembled genome comprises 2,392,629 bp, with 37.69% G+C content and 2,265 protein-coding genes.
PubMed: 36946783
DOI: 10.1128/mra.00105-23 -
Animals : An Open Access Journal From... Feb 2023This study aims to investigate the effect of neem leaf supplementation on the feed intake, digestibility, performance, fermentation characteristics, and ruminal microbes...
This study aims to investigate the effect of neem leaf supplementation on the feed intake, digestibility, performance, fermentation characteristics, and ruminal microbes in goats. We included 24 Anglo-Nubian Thai native male goats with a body weight of 20 ± 2.0 kg, using 2 × 2 factorial in a completely randomized design for the following four treatments: (1) control, (2) control + 15% PEG in the concentrate, (3) 6% NL in concentrate, and (4) 6% NL + 15% PEG in concentrate. The results show that supplementation with 6% NL + 15% PEG in the concentrate had a higher ( < 0.05) feed intake gDM/d, % BW, g/kgBW, nutrient intake, nutrient digestion, weight change, and ADG than did the goats that were fed with 0% NL + 0% PEG, 0% NL + 15% PEG, and 6% NL + 0% PEG in concentrate, respectively. The feeding with 6% NL + 15% PEG had a higher ( < 0.05) level of propionic acid at 2 and 4 h post feeding compared to the other treatments. Supplementation with 6% NL + 15% PEG in the concentrate had the lowest ( < 0.05) methanogen, protozoa, blood urea nitrogen, ammonia nitrogen, acetic acid, and butyric acid, as well as a lower ratio of acetic acid to propionic acid at 2 and 4 h post feeding than the other treatments. However, supplementation with 6% NL + 15% PEG in concentrate had the highest values of and at 2 and 4 h post feeding compared to the other treatments ( < 0.05). Collectively, this study indicates that neem leaf supplements can increase growth performance and propionic acid and can modulate the abundance of and . Thus, neem leaf could potentially be a good supplement for goat feed.
PubMed: 36899747
DOI: 10.3390/ani13050890 -
Cureus Feb 2023The diagnosis of infective endocarditis is challenging because it has a variable clinical presentation and nonspecific symptoms and can present in different forms,...
The diagnosis of infective endocarditis is challenging because it has a variable clinical presentation and nonspecific symptoms and can present in different forms, especially when an unusual etiological agent is involved. We present the case of a female in her 70s admitted to the hospital with a medical history of bicytopenia, severe aortic stenosis, and rheumatoid arthritis. She had several consultations during which she presented with asthenia and general malaise. A septic screen test was performed that would determine that was present in a blood culture (BC), which was not valued. About three months later, she was hospitalized. In the first 24 hours of admission, the septic screen test was repeated and was isolated in BC. Splenic infarctions and transthoracic echocardiography suggested probable endocarditis, which was confirmed with transesophageal echocardiography. She underwent surgical intervention to remove the perivalvular abscess and replace the aortic prosthesis.
PubMed: 36879704
DOI: 10.7759/cureus.34529