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Clinical Microbiology and Infection :... Jan 2016Aerococci have often been misidentified as streptococci in microbiology laboratories, leading to an underestimation of these bacteria as causes of human infections. An... (Review)
Review
Aerococci have often been misidentified as streptococci in microbiology laboratories, leading to an underestimation of these bacteria as causes of human infections. An increased awareness of aerococci and the introduction of matrix-assisted laser desorption ionization time-of-flight mass spectrometry, has led to an increased isolation of Aerococcus urinae and Aerococcus sanguinicola from human urine and blood. The two species are found in human urine and can cause urinary tract infections (UTI). Aerococcus urinae can, in older males with underlying urinary tract conditions, cause invasive infections such as urosepsis or infective endocarditis. The prognosis of invasive aerococcal infections appears to be relatively favourable despite the old age of patients and their many comorbidities. Though clinical breakpoints are still not in place, aerococci seem to be sensitive to penicillins, carbapenems and vancomycin. There is synergy between penicillin and aminoglycosides against some A. urinae isolates and this combination is often used in aerococcal infective endocarditis. The treatment of complicated aerococcal UTI is not obvious as many isolates are resistant to fluoroquinolones. In addition, A. urinae is resistant to sulphamethoxazole, and there are methodological problems in the determination of trimethoprim sensitivity. In complicated UTI, ampicillin is probably a safe treatment option, whereas nitrofurantoin is probably effective in uncomplicated UTI. Treatment studies in aerococcal infections are needed as is a better understanding of the natural niches for aerococci and the pathogenesis and clinical course of aerococcal infections.
Topics: Aerococcus; Anti-Bacterial Agents; Blood; Endocarditis, Bacterial; Gram-Positive Bacterial Infections; Humans; Microbial Sensitivity Tests; Sepsis; Urinary Tract Infections; Urine
PubMed: 26454061
DOI: 10.1016/j.cmi.2015.09.026 -
Microbiology Spectrum Apr 2016Gram-positive bacteria are a common cause of urinary-tract infection (UTI), particularly among individuals who are elderly, pregnant, or who have other risk factors for... (Review)
Review
Gram-positive bacteria are a common cause of urinary-tract infection (UTI), particularly among individuals who are elderly, pregnant, or who have other risk factors for UTI. Here we review the epidemiology, virulence mechanisms, and host response to the most frequently isolated Gram-positive uropathogens: Staphylococcus saprophyticus, Enterococcus faecalis, and Streptococcus agalactiae. We also review several emerging, rare, misclassified, and otherwise underreported Gram-positive pathogens of the urinary tract including Aerococcus, Corynebacterium, Actinobaculum, and Gardnerella. The literature strongly suggests that urologic diseases involving Gram-positive bacteria may be easily overlooked due to limited culture-based assays typically utilized for urine in hospital microbiology laboratories. Some UTIs are polymicrobial in nature, often involving one or more Gram-positive bacteria. We herein review the risk factors and recent evidence for mechanisms of bacterial synergy in experimental models of polymicrobial UTI. Recent experimental data has demonstrated that, despite being cleared quickly from the bladder, some Gram-positive bacteria can impact pathogenic outcomes of co-infecting organisms. When taken together, the available evidence argues that Gram-positive bacteria are important uropathogens in their own right, but that some can be easily overlooked because they are missed by routine diagnostic methods. Finally, a growing body of evidence demonstrates that a surprising variety of fastidious Gram-positive bacteria may either reside in or be regularly exposed to the urinary tract and further suggests that their presence is widespread among women, as well as men. Experimental studies in this area are needed; however, there is a growing appreciation that the composition of bacteria found in the bladder could be a potentially important determinant in urologic disease, including susceptibility to UTI.
Topics: Animals; Bacteriuria; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Humans; Microbiota; Urinary Tract; Urinary Tract Infections
PubMed: 27227294
DOI: 10.1128/microbiolspec.UTI-0012-2012 -
European Urology Jun 2021Little is known about the role of the genitourinary and gastrointestinal microbiota in the pathogenesis of male infertility.
BACKGROUND
Little is known about the role of the genitourinary and gastrointestinal microbiota in the pathogenesis of male infertility.
OBJECTIVE
To compare the taxonomic and functional profiles of the gut, semen, and urine microbiomes of infertile and fertile men.
DESIGN, SETTING, AND PARTICIPANTS
We prospectively enrolled 25 men with primary idiopathic infertility and 12 healthy men with proven paternity, and we collected rectal swabs, semen samples, midstream urine specimens, and experimental controls.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS
We performed comprehensive semen analysis, 16S rRNA sequencing for quantitative high-resolution taxonomy, and shotgun metagenomics with a median of 140 million reads per sample for functional metabolic pathway profiling.
RESULTS AND LIMITATIONS
We identified a diverse semen microbiome with modest similarity to the urinary microbiome. Infertile men harbored increased seminal α-diversity and distinct β-diversity, increased seminal Aerococcus, and decreased rectal Anaerococcus. Prevotella abundance was inversely associated with sperm concentration, and Pseudomonas was directly associated with total motile sperm count. Vasectomy appeared to alter the seminal microbiome, suggesting a testicular or epididymal contribution. Anaerobes were highly over-represented in the semen of infertile men with a varicocele, but oxidative stress and leukocytospermia were associated with only subtle differences. Metagenomics data identified significant alterations in the S-adenosyl-L-methionine cycle, which may play a multifaceted role in the pathogenesis of infertility via DNA methylation, oxidative stress, and/or polyamine synthesis.
CONCLUSIONS
This pilot study represents the first comprehensive investigation into the microbiome in male infertility. These findings provide the foundation for future investigations to explore causality and identify novel microbiome-based diagnostics and therapeutics for men with this complex and emotionally devastating disease.
PATIENT SUMMARY
We explored the resident populations of bacteria living in the gut, semen, and urine of infertile and fertile men. We found several important bacterial and metabolic pathway differences with the potential to aid in diagnosing and treating male infertility in the future.
Topics: Dysbiosis; Humans; Infertility, Male; Male; Microbiota; Pilot Projects; RNA, Ribosomal, 16S; Semen; Sperm Motility
PubMed: 33573862
DOI: 10.1016/j.eururo.2021.01.014 -
Microbiology Spectrum Feb 2023Aerococcus urinae and Aerococcus sanguinicola have been increasingly recognized as causative agents of urinary tract infection (UTI) during the last decade. Nitroxoline...
Aerococcus urinae and Aerococcus sanguinicola have been increasingly recognized as causative agents of urinary tract infection (UTI) during the last decade. Nitroxoline achieves high urinary concentrations after oral administration and is recommended in uncomplicated UTI in Germany, but its activity against spp. is unknown. The aim of this study was to assess the susceptibility of clinical species isolates to standard antibiotics and to nitroxoline. Between December 2016 and June 2018, 166 and 18 isolates were recovered from urine specimens sent to the microbiology laboratory of the University Hospital of Cologne, Germany. Susceptibility to standard antimicrobials was analyzed by disk diffusion (DD) according to EUCAST methodology, nitroxoline was tested by DD and agar dilution. Susceptibility of spp. to benzylpenicillin, ampicillin, meropenem, rifampicin, nitrofurantoin, and vancomycin was 100% and resistance was documented only against ciprofloxacin (20 of 184; 10.9%). MICs of nitroxoline in isolates were low (MIC 1/2 mg/L) while significantly higher MICs were observed in (MIC 64/128 mg/L). If the EUCAST nitroxoline breakpoint for E. coli and uncomplicated UTI was applied (16 mg/L), 97.6% of isolates would be interpreted as susceptible while all isolates would be considered resistant. Nitroxoline demonstrated high activity against clinical isolates, but low activity against Nitroxoline is an approved antimicrobial for UTI and could be an alternative oral drug to treat urinary tract infection, yet clinical studies are needed to demonstrate this potential . and have been increasingly recognized as causative agents in urinary tract infections. Currently, there are few data available on the activity of different antibiotics against these species and no data on nitroxoline. We demonstrate that clinical isolates in Germany are highly susceptible to ampicillin, while resistance to ciprofloxacin was common (10.9%). Additionally, we show that nitroxoline is highly active against , but not against , which based on the presented data, should be considered intrinsically resistant. The presented data will help to improve the therapy of urinary tract infections by species.
PubMed: 36847493
DOI: 10.1128/spectrum.02763-22 -
International Journal of Infectious... Jan 2021We describe our multicenter experience on diagnosis and management of Aerococcus bacteremia including the susceptibility profile of Aerococcus species and a suggested...
OBJECTIVES
We describe our multicenter experience on diagnosis and management of Aerococcus bacteremia including the susceptibility profile of Aerococcus species and a suggested algorithm for clinicians.
METHODS
Retrospective study of all patients with positive blood cultures for Aerococcus species from January 2005 to July 2020 in our institution with clinical data and susceptibility profile. Data were collected from both electronic health record and clinical microbiology laboratory database.
RESULTS
There were 219 unique isolates with only the susceptibility profiles available, while 81 patients had clinical information available. Forty-nine of those cases were deemed as true bloodstream infection and the rest were of unclear clinical significance. Cases of endocarditis (n = 7) were high-grade, monomicrobial bacteremia caused by Aerococcus urinae. Patients with endocarditis were younger (66 vs 80 p < 0.05). The risk for endocarditis was higher if duration of symptoms was longer than 7 days (OR 105, 95% CI: 5-2271), or if there were septic emboli (OR 71, 95% CI: 3-1612). A DENOVA score cutoff of ≥ 3 was 100% sensitive and 89% specific in detecting endocarditis. The 30-day and 3-month all-cause mortality for bacteremia was 17% and 24%, respectively. Six out of seven patients with endocarditis survived.
CONCLUSIONS
Antibiotic regimen for aerococcal bloodstream infections and endocarditis should be guided by species identification and antimicrobial susceptibility testing. DENOVA scoring system's performance in this study is more congruent to other studies. Hence, it can be used as an adjunctive tool in assessing the need for echocardiogram to rule out endocarditis. In our experience, two and four weeks of treatment for bloodstream infections and endocarditis, respectively, had good outcomes.
Topics: Adult; Aerococcus; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacteremia; Endocarditis, Bacterial; Female; Gram-Positive Bacterial Infections; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Retrospective Studies; Sepsis; Young Adult
PubMed: 33157289
DOI: 10.1016/j.ijid.2020.10.096 -
Cureus Apr 2022is a gram-positive organism frequently found in the urinary tract. It is often mistaken for and based on its appearance. It commonly causes urinary tract infections...
is a gram-positive organism frequently found in the urinary tract. It is often mistaken for and based on its appearance. It commonly causes urinary tract infections but has rarely been associated with fatal infective endocarditis and sepsis. We present a case of infective endocarditis and discuss echocardiographic imaging findings and management approach.
PubMed: 35547451
DOI: 10.7759/cureus.23947 -
Journal of Microscopy and Ultrastructure 2021is a Gram-positive, catalase- and oxidase-negative, microaerophilic, nonmotile bacteria species rarely associated with human infections such as arthritis, bacteremia,...
INTRODUCTION
is a Gram-positive, catalase- and oxidase-negative, microaerophilic, nonmotile bacteria species rarely associated with human infections such as arthritis, bacteremia, endocarditis, and meningitis. The bacteria are also often confused with streptococci species or treated as a contaminant.
PATIENTS AND METHODOLOGY
We conducted a retrospective, observational cohort study on all patients with isolates in blood samples from July 2010 to June 2019. All categorical data were presented as counts and proportions, whereas continuous data were presented as median and interquartile ranges.
RESULTS
A total of 20 isolates were identified over the study period of 9 years. Of these, was isolated in 10 (50%), in 6 (30%), and (not speciated) in 4 (20%). The median age was 74.3 years (12 males and 8 females). The two most frequent presentations were fever (15 of 20) and altered mentation (6 of 15). Most of the patients (11 of 15) had at least one predisposing comorbidity related to the urinary tract system (8 with recurrent urinary tract infection, 7 with urinary incontinence, 3 with an indwelling catheter, 2 with renal stones, and 1 each with benign prostatic hyperplasia and a recent cystoscopy). The median white blood cell count was 18,426 cells/mL, median hemoglobin 10.96 g/dL, median platelet count 191,000 cells/μL, median blood urea nitrogen 28.6 mg/dL, and median creatinine 1.54 mg/dL. The urinary tract was the most likely source of bacteremia (10 of 20) based on either imaging findings (5 cases), positive urine culture for (4 cases), or instrumentation history (1 case). In the rest, the cause of bacteremia could not be found. Endocarditis was suspected in 9 out of 20 patients. Transthoracic echocardiography/transesophageal echocardiography (TEE) confirmed 3 cases (2 aortic valves, 1 mitral valve and pacemaker). Interestingly, one case had septic emboli causing a right frontal stroke with a normal TEE and normal Doppler study for deep venous thrombosis. Blood cultures were positive in 35% (7 of 20) with polymicrobial growth, 3 with coagulase-negative staphylococci, 2 with , and the other 2 each with and Of the 20 cases, 9 and 10 required intensive care unit level care and vasopressor support, respectively. Most of the patients were treated for 5-14 days except the 3 cases with infective endocarditis (IE). The median hospital stay duration was 6.55 days with 2 fatalities (2 out of 20 patients).
CONCLUSION
Old age and underlying urologic conditions are the best-known risk factors for infection. Recent advances in diagnostic technology have led to an increase in detection of -related infections. The rare occurrence of in human infections and resultant lack of randomized control trials have resulted in a significant degree of clinical uncertainty in the management of IE.
PubMed: 33850708
DOI: 10.4103/JMAU.JMAU_61_19 -
Antibiotics (Basel, Switzerland) Aug 2023Bovine mastitis is a polymicrobial disease characterised by inflammation of the udders of dairy and beef cattle. The infection has huge implications to health and... (Review)
Review
Bovine mastitis is a polymicrobial disease characterised by inflammation of the udders of dairy and beef cattle. The infection has huge implications to health and welfare of animals, impacting milk and beef production and costing up to EUR 32 billion annually to the dairy industry, globally. Bacterial communities associated with the disease include representative species from , , , , , , and . Conventional treatment relies on antibiotics, but antimicrobial resistance, declining antibiotic innovations and biofilm production negatively impact therapeutic efficacy. Bacteriophages (phages) are viruses which effectively target and lyse bacteria with extreme specificity and can be a valuable supplement or replacement to antibiotics for bovine mastitis. In this review, we provide an overview of the etiology of bovine mastitis, the advantages of phage therapy over chemical antibiotics for the strains and research work conducted in the area in various model systems to support phage deployment in the dairy industry. We emphasise work on phage isolation procedures from samples obtained from mastitic and non-mastitic sources, characterisation and efficacy testing of single and multiple phages as standalone treatments or adjuncts to probiotics in various in vitro, ex vivo and in vivo bovine mastitis infection models. Furthermore, we highlight the areas where improvements can be made with focus on phage cocktail optimisation, formulation, and genetic engineering to improve delivery, stability, efficacy, and safety in cattle. Phage therapy is becoming more attractive in clinical medicine and agriculture and thus, could mitigate the impending catastrophe of antimicrobial resistance in the dairy sector.
PubMed: 37627727
DOI: 10.3390/antibiotics12081307 -
Journal of Medical Microbiology Jul 2021Periodontitis, one of the most common oral disorders in sheep, is caused by a mixed and opportunistic microbiota that severely affects the health and welfare of...
Periodontitis, one of the most common oral disorders in sheep, is caused by a mixed and opportunistic microbiota that severely affects the health and welfare of animals. However, little is known about the ecological processes involved and the composition of the microbiota associated with the development of the disease. Using high-throughput sequencing of the 16S ribosomal RNA gene and network analysis it would be possible to discriminate the microbiomes of clinically healthy sheep and those with periodontitis and possibly identify the key microorganisms associated with the disease. The present study aimed to characterise the composition of dental microbiomes and bacterial co-occurrence networks in clinically healthy sheep and animals with periodontitis. Dental biofilm samples were collected from ten sheep with periodontitis and ten clinically healthy animals. Bacteria were identified using high-throughput sequencing of the 16S ribosomal RNA gene. The most prevalent genera in the dental microbiota of sheep with periodontitis were , , and . In clinically healthy animals, the most significant genera were unclassified and was found at high prevalence in the microbiomes of both groups. The dental microbiota of sheep in the two clinical conditions presented different profiles and the diversity and richness of bacteria was greater in the diseased animals. Network analyses showed the presence of a large number of antagonistic interactions between bacteria in the dental microbiota of animals with periodontitis, indicating the occurrence of a dysbiotic community. Through the interrelationships, members of the genus are likely to be key pathogens, both in the dental microbiota of healthy animals and those with periodontitis. stood out among the top three nodes with more centrality and the largest number of hubs in the networks of animals with periodontitis. The dental biofilm microbiota associated with ovine periodontitis is dysbiotic and with significant antagonistic interactions, which discriminates healthy animals from diseased animals and highlights the importance of key bacteria, such as , , and species.
Topics: Animals; Bacteria; Biofilms; Ecology; High-Throughput Nucleotide Sequencing; Microbiota; Periodontitis; RNA, Ribosomal, 16S; Sheep
PubMed: 34313584
DOI: 10.1099/jmm.0.001396 -
Animals : An Open Access Journal From... Jun 2022With the development of modern pig raising technology, the increasing density of animals in pig houses leads to the accumulation of microbial aerosols in pig houses. It...
With the development of modern pig raising technology, the increasing density of animals in pig houses leads to the accumulation of microbial aerosols in pig houses. It is an important prerequisite to grasp the characteristics of bacteria in aerosols in different pig houses to solve the problems of air pollution and disease prevention and control in different pig houses. This work investigated the effects of growth stages on bacterial aerosol concentrations and bacterial communities in pig houses. Three traditional types of closed pig houses were studied: farrowing (FAR) houses, weaning (WEA) houses, and fattening (FAT) houses. The Andersen six-stage sampler and high-volume air sampler were used to assess the concentrations and size distribution of airborne bacteria, and 16S rRNA gene sequencing was used to identify the bacterial communities. We found that the airborne bacterial concentration, community richness, and diversity index increased with pig age. We found that , , , , and in the microbial aerosols of pig houses have the potential risk of causing disease. These differences lead us to believe that disinfection strategies for pig houses should involve a situational focus on environmental aerosol composition on a case-by-case basis.
PubMed: 35739876
DOI: 10.3390/ani12121540