Actinobaculum Schaalii Research Articles

Use of MALDI-TOF MS in diagnostic microbiology for identification of species that conventional methods usually fail to identify

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been used in clinical diagnostic laboratories for the identification of microorganisms. It has a relevant advantage compared to other methods in terms of speed to provide results, being an alternative for addressing restrictions in clinical diagnosis as it may replace or complement existing identification techniques. This is especially important because some rare microorganisms would be identified only by higher cost techniques which are not widely available, such as genetic sequencing. Thus, the present paper reports two cases in which uncommon microorganisms were identified effectively and quickly. Keywords: Non-tuberculous Mycobacteria; Mycobacterium abscessus; Bacterial infections; Actinotignum schaalii; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Actinotignum Schaalii bacteremia: from microbiota to the infection

Actinotignum schaalii is a gram-positive, facultative anaerobic bacillus, an opportunist agent that is underestimated or mistaken as a contaminant. In this article, we present a case of sepsis with multiorgan dysfunction due to acute pyelonephritis complicated by A. schaalii bacteraemia in an elderly patient with diabetes mellitus, chronic obstructive renal disease, benign prostatic hyperplasia, renal lithiasis and chronic urinary device. Through specific laboratory techniques such as Matrix-Assisted Laser Desorption/Ionisation Time-Of-Flight Mass Spectrometry, it was possible to identify the presence of A. schaalii in blood cultures. However, uroculture was negative. After 20 days of β-lactam, it was possible to successfully heal the infection. The difficulty in identifying this rare agent has definitely constrained our diagnostic and therapeutic approach.

A Case of Urinary Tract Infection Caused by the Emerging Uropathogen Actinotignum schaalii

A Case of Urinary Tract Infection Caused by the Emerging Uropathogen <i>Actinotignum schaalii</i>

Treatment considerations for potential uropathogens detected by precision microbiological testing.

The clinical and microbiological data for urinary tract infections (UTIs) for 6 organisms detected by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) at community health systems were examined. The use of precision microbiological diagnostic testing such as MALDI-TOF and real-time quantitative polymerase chain reaction has increased the ability to detect a wider spectrum of organisms. This has raised questions of the clinical relevance of infrequently encountered organisms, especially when cultured from urine. This article reviews clinical and microbiological data for UTIs for 6 organisms detected by MALDI-TOF at community health systems (Actinotignum schaalii, Chryseobacterium indologenes, Aerococcus urinae, Aerococcus sanguinicola, Corynebacterium riegelii, and Corynebacterium urealyticum). Since little information currently exists, most of the data associating the aforementioned organisms with UTIs were derived from case reports. Although these organisms are more readily identified using precision microbiological diagnostic testing methods, infection should not be assumed based on culture results alone since asymptomatic bacteriuria has been reported. Similar to more common urinary pathogens, clinical correlation is essential. To facilitate treatment, we provide a table of empirical options likely to achieve clinical success based on in vivo and in vitro data. If available, pathogen-specific susceptibility data should be used to direct therapy. Clinical and microbiological data and potential treatment options were presented for 6 traditionally underrecognized organisms that are increasingly being found from urinary specimens. The treatment recommendations should be interpreted cautiously as they were devised through the use of very limited data.

Aerococcus urinae, Alloscardovia omnicolens, and Actinotignum schaalii: the AAA Minor League Team of Urinary Tract Infection Pathogens

In clinical microbiology laboratories, advancements in the methods used for routine organism identification have facilitated more accurate species level resolution. This, along with increasing knowledge regarding “new” pathogens, has provided new insights into biology and has revealed clinical associations not previously known. Aerococcus urinae, Alloscardovia omnicolens, and Actinotignum schaalii are Gram-positive bacteria associated with urinary tract infections but can also be members of the urinary tract microbiota. In addition, invasive infections have been reported for the three bacteria, usually with a urinary tract source. Importantly, the use of routine biochemical testing methods for identification of these bacteria can result in misidentification or the incorrect determination that they are not clinically significant. Of these bacteria, only A. urinae has antimicrobial susceptibility testing criteria and interpretative breakpoints. Microbiologists and clinicians need to be aware of these urinary tract pathogens and how to correctly identify them.

Significant increase in cultivation of Gardnerella vaginalis, Alloscardovia omnicolens, Actinotignum schaalii, and Actinomyces spp. in urine samples with total laboratory automation

While total laboratory automation (TLA) is well established in laboratory medicine, only a few microbiological laboratories are using TLA systems. Especially in terms of speed and accuracy, working with TLA is expected to be superior to conventional microbiology. We compared in total 35,564 microbiological urine cultures with and without incubation and processing with BD Kiestra TLA for a 6-month period each retrospectively. Sixteen thousand three hundred thirty-eight urine samples were analyzed in the pre-TLA period and 19,226 with TLA. Sixty-two percent (n = 10,101/16338) of the cultures processed without TLA and 68% (n = 13,102/19226) of the cultures processed with TLA showed growth. There were significantly more samples with two or more species per sample and with low numbers of colony forming units (CFU) after incubation with TLA. Regarding the type of bacteria, there were comparable amounts of Enterobacteriaceae in the samples, slightly less non-fermenting Gram-negative bacteria, but significantly more Gram-positive cocci, and Gram-positive rods. Especially Alloscardivia omnicolens, Gardnerella vaginalis, Actinomyces spp., and Actinotignum schaalii were significantly more abundant in the samples incubated and processed with TLA. The time to report was significantly lower in the TLA processed samples by 1.5 h. We provide the first report in Europe of a large number of urine samples processed with TLA. TLA showed enhanced growth of non-classical and rarely cultured bacteria from urine samples. Our findings suggest that previously underestimated bacteria may be relevant pathogens for urinary tract infections. Further studies are needed to confirm our findings.

Draft genome sequence of Actinotignum schaalii DSM 15541T: Genetic insights into the lifestyle, cell fitness and virulence.

The permanent draft genome sequence of Actinotignum schaalii DSM 15541T is presented. The annotated genome includes 2,130,987 bp, with 1777 protein-coding and 58 rRNA-coding genes. Genome sequence analysis revealed absence of genes encoding for: components of the PTS systems, enzymes of the TCA cycle, glyoxylate shunt and gluconeogensis. Genomic data revealed that A. schaalii is able to oxidize carbohydrates via glycolysis, the nonoxidative pentose phosphate and the Entner-Doudoroff pathways. Besides, the genome harbors genes encoding for enzymes involved in the conversion of pyruvate to lactate, acetate and ethanol, which are found to be the end products of carbohydrate fermentation. The genome contained the gene encoding Type I fatty acid synthase required for de novo FAS biosynthesis. The plsY and plsX genes encoding the acyltransferases necessary for phosphatidic acid biosynthesis were absent from the genome. The genome harbors genes encoding enzymes responsible for isoprene biosynthesis via the mevalonate (MVA) pathway. Genes encoding enzymes that confer resistance to reactive oxygen species (ROS) were identified. In addition, A. schaalii harbors genes that protect the genome against viral infections. These include restriction-modification (RM) systems, type II toxin-antitoxin (TA), CRISPR-Cas and abortive infection system. A. schaalii genome also encodes several virulence factors that contribute to adhesion and internalization of this pathogen such as the tad genes encoding proteins required for pili assembly, the nanI gene encoding exo-alpha-sialidase, genes encoding heat shock proteins and genes encoding type VII secretion system. These features are consistent with anaerobic and pathogenic lifestyles. Finally, resistance to ciprofloxacin occurs by mutation in chromosomal genes that encode the subunits of DNA-gyrase (GyrA) and topisomerase IV (ParC) enzymes, while resistant to metronidazole was due to the frxA gene, which encodes NADPH-flavin oxidoreductase.

Propionimicrobium lymphophilum and Actinotignum schaalii bacteraemia: a case report.

Propionimicrobium lymphophilum is an anaerobic Gram-positive bacillus that exists in human skin and urinary tract. The pathogenicity is, however, not well known. Only two cases of urinary tract infection have been described recently. In the case presented here, the bacterium was isolated, concomitant with Actinotignum schaalii, from blood culture of a patient with fever and difficulty of urination. The bacteria were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA sequencing. The case was successfully treated with ampicillin/sulbactam.

Recurrent obstructive acute pyelonephritis: A rare form of Actinotignum (Actinobaculum) schaalii infection in a HIV-1 infected patient

Actinobaculum schaalii is a rarely reported, anaerobic, Gram-positive bacterium which role as uropathogen is emerging. We report here the case of a 47 year old HIV-1 infected woman presented with five recurrent episodes of obstructive pyelonephritis in the context of multiple renal stones. No bacteria was found until the fifth episode, during which prolonged urinary cultures as well as 16S rDNA sequencing allowed the diagnosis of A. schaalii infection. She had developed a life-threatening condition with severe renal failure. A right nephrectomy was performed and found that the intrarenal stones were attributed to the antiretroviral therapy. The renal parenchyma corresponded to an end-stage renal disease with chronic pyelonephritis without abcesses or granules. The situation improved after six months of amoxicillin therapy.

Prevalence of Actinotignum schaalii in patients with urinary tract infections combined with leukocyturia and inconclusive bacteriological results

Prevalence of Actinotignum schaalii in patients with urinary tract infections combined with leukocyturia and inconclusive bacteriological results

Actinotignum (formerly Actinobaculum) schaalii: a review of MALDI-TOF for identification of clinical isolates, and a proposed method for presumptive phenotypic identification

Actinotignum schaalii is a recognised cause of urinary tract infection. Following a case of urosepsis, 20 isolates of A.schaalii were collected over an initial 18 month period from urine and blood culture. An additional 25 isolates were collected over the following 13 months. Actinotignum schaalii had likely been overlooked or dismissed as a contaminant in our laboratory prior to this study period. It grows slowly on blood agar with supplemental CO2 or anaerobically. It may not grow on MacConkey agar or chromogenic agars used for routine urine culture. Repeated attempts at identification by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) may be required as the optimal age of cultures for testing is unclear. Utilising its characteristic antibiogram may assist phenotypic identification of this organism which is otherwise difficult to distinguish from other actinomycetes.

Description of strain FC3T as the neotype strain of Actinobaculum massiliense.

Actinobaculum massiliense (Euzéby, 2006) was isolated from the urine of an elderly woman in 2001. Unfortunately, the strain deposited as the type strain was, by error, an Actinobaculum schaalii strain (Yassin et al., 2015). In 2015, we isolated a new strain of A. massiliense, FC3, from the urine of a 12-year-old patient with acute cystitis. We herein present the characteristics of strain FC3 (=CSUR P1982=DSM 100580) and formally propose it as the neotype strain of A. massiliense.

Actinobaculum schaalii: A truly emerging pathogen?: Actinobaculum schaalii: un pathogène réellement émergent?

Actinobaculum schaalii is a Gram-positive facultative anaerobe bacillus. It is a commensal organism of the genitourinary tract. Its morphology is nonspecific. Aerobic culture is tedious, and identification techniques have long been inadequate. Thus, A. schaalii has often been considered as a nonpathogen bacterium or a contaminant. Its pathogenicity is now well described in urinary tract infections, and infections in other sites have been reported. This pathogen is considered as an emerging one following the growing use of mass spectrometry identification. In this context, the aim of our study was to evaluate the number of isolations of A. schaalii before and after the introduction of mass spectrometry in our hospital and to study the clinical circumstances in which isolates were found.

Answer to November 2015 Photo Quiz

Answer: Actinobaculum schaalii. The Gram stain of material from the abscess showed many Gram-positive cocci and Gram-negative coccobacilli. The organism that grew in aerobic culture initially presented as a pleomorphic Gram-positive organism with both coccoid and rod-shaped forms. After extended

A validation of the Danish microbiology database (MiBa) and incidence rate of Actinotignum schaalii (Actinobaculum schaalii) bacteraemia in Denmark

Actinotignum schaalii (former named Actinobaculum schaalii) can cause urinary tract infections (UTIs) and bacteraemia, mainly in the elderly. A. schaalii is difficult to identify with conventional biochemical tests, and it is often overlooked if the urine is only cultured in ambient air. The aim of this study was to validate data from the nationwide Danish microbiology database (MiBa) with data from the laboratory information system (LIS) at the local department of microbiology in Viborg-Herning, and to evaluate the incidence rate of bacteraemia caused by A. schaalii in Denmark by using data from the MiBa. All departments of microbiology in Denmark report data to the MiBa. All microbiological samples with A. schaalii in Denmark were extracted for a period of 5 years from the MiBa and from the local LISs. All data obtained from our local LIS were also found in the MiBa, except for data on real-time PCR, which were not registered, owing to missing ID codes in the MiBa. From 2010 to 2014, there was a significant increase in the incidence rate of blood cultures with A. schaalii, from 1.8 to 6.8 cases per million, which was probably due to coincident implementation of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) in routine diagnostics. We found that A. schaalii caused bacteraemia and UTIs mainly in the elderly. In conclusion, the MiBa can be a useful source of nationwide microbiological data in Denmark. Our results suggest that the incidence rate of A. schaalii as a cause of bacteraemia has been underestimated, and that culture of urine in CO2 can improve the detection of A. schaalii.

Actinobaculum shaalii: a new uropathogen?

&lt;em&gt;Background&lt;/em&gt; &lt;em&gt;and&lt;/em&gt; &lt;em&gt;Aims&lt;/em&gt;. &lt;em&gt;Actinobaculum&lt;/em&gt; &lt;em&gt;schaalii&lt;/em&gt; is a facultative anaerobic, Gram-positive rod-shaped species phylogenetically related to Actinomyces. &lt;em&gt;A&lt;/em&gt;. &lt;em&gt;schaalii&lt;/em&gt; is an emerging pathogen causing urinary tract infections (UTI) in both children and adults; although, as part of the human genitourinary tract flora, it is frequently overlooked or considered as a contaminant. While the phenotypic identification of &lt;em&gt;A&lt;/em&gt;. &lt;em&gt;schaalii&lt;/em&gt; is difficult, the recent Matrix-Assisted Laser Desorption/Ionisation Time-Of-Flight-mass spectrometry (MALDI TOF) technology could represent a promising tool for its identification. &lt;br /&gt;&lt;em&gt;Materials&lt;/em&gt; &lt;em&gt;and&lt;/em&gt; &lt;em&gt;Methods&lt;/em&gt;. This is a retrospective study including all known cases (n=7) of &lt;em&gt;A&lt;/em&gt;. &lt;em&gt;schaalii&lt;/em&gt; infections occurred (between July 2013 and November 2013) at the Microbiology Laboratory of the A. Cardarelli Hospital, in Campobasso (Italy). &lt;br /&gt;&lt;em&gt;Results&lt;/em&gt;. All the 7 &lt;em&gt;A.&lt;/em&gt; &lt;em&gt;schaalii&lt;/em&gt; collected strains, resulted &lt;em&gt;in&lt;/em&gt; &lt;em&gt;vitro&lt;/em&gt; susceptible to most of the drugs commonly used for urinary tract infections, but resistant to ciprofloxacin, a first-line antibiotic in the treatment of prostatitis. All isolates were susceptible to amoxicillin, amoxicillin-clavulanic, ampicillin-sulbactam, cefuroxime, gentamicin, piperacillin-tazobactam, vancomicin, tetracycline (no EUCAST breakpoints). All except two isolates were susceptible to cefotaxime; 3/7 and 5/7 strains were clindamicin and levofloxacin resistant, respectively. &lt;br /&gt;&lt;em&gt;Conclusions&lt;/em&gt;. As most antibiotics empirically prescribed for UTI (mainly fluoroquinolones or trimethoprim/sulfamethoxazole) are not effective against &lt;em&gt;A&lt;/em&gt;. &lt;em&gt;schaalii&lt;/em&gt;, the appropriate onset of treatment was delayed by an average of 2.8 days. The implementation of the newer MALDI TOF technology in routine diagnostic procedures may allow a more reliable and rapid identification of &lt;em&gt;A&lt;/em&gt;. &lt;em&gt;schaalii&lt;/em&gt; in future.

Actinobaculum schaalii bacteremia: A report of two cases

We report two cases of bacteremia with Actinobaculum schaalii, a rarely reported, anaerobic, Gram-positive bacterium. The first case was a patient with renal cancer who developed pyelonephritis after cryoablation, and the second was a patient who developed sepsis after a urogenital procedure. Bacteremia resolved after administration of empiric antibiotic therapy.

Urinary tract infection caused by Actinobaculum schaalii: a urosepsis pathogen that should not be underestimated

Introduction: Actinobaculum schaalii is a Gram‐positive facultative anaerobic coccoid rod bacterium that grows slowly in culture. This bacterium was classified as a new genus in 1997 but is often overlooked or considered a contaminant because of both its resemblance to the normal bacterial flora on skin and mucosa and the overgrowth of other bacteria. During the past decade, A. schaalii has emerged as a more common urinary tract pathogen than previously thought. Case presentation: Here, we describe the case of a patient with an untreated A. schaalii urinary tract infection that turned into urosepsis. Conclusion: This case shows that the invasive potential of this bacterium should not always be ruled out.

Mise au point : les uropathogènes émergents

Technological advances during the last years in bacterial identification by molecular biology and mass spectrometry, or Matrix Assisted Laser Desorption Ionisation-Time of Flight (MALDI-TOF) have allowed identifying new bacteria involved in urinary tract infections. The purpose of this review is to familiarize clinicians with these bacteria so that they can look at a particular target population and help biologists to suspect and identify them. A bibliographic research was performed using the Medline database concerning the keywords Aerococcus, Actinobaculum, Alloscardovia, Trueperella. If Aerococcus sp. is now well known, Actinobaculum sp., Alloscardovia sp. and Trueperella sp. remain rarely isolated and unknown from clinicians. Importance of these germs could be underestimated because of the identifying and isolation difficulties which existed beforehand. They are particularly found in a population of elderly people with underlying conditions or urological risk factors of urinary tract infection. Actinobaculum schaalii is also found more frequently in young children. Aerococcus sp. et A.schaalii are true uropathogens not to be underestimated. Further studies are still needed to confirm the specific involvement of Trueperella and Alloscardovia in urinary diseases.

Dissection of the genus Actinobaculum: Reclassification of Actinobaculum schaalii Lawson et al. 1997 and Actinobaculum urinale Hall et al. 2003 as Actinotignum schaalii gen. nov., comb. nov. and Actinotignum urinale comb. nov., description of Actinotignum sanguinis sp. nov. and emended descriptions of the genus Actinobaculum and Actinobaculum suis; and re-examination of the culture deposited as Actinobaculum massiliense CCUG 47753T (

The remarkable host specificity of the species of the genus Actinobaculum led us to recharacterize these species by a polyphasic approach. A comparative chemotaxonomic study including analysis of whole-cell sugars, amino acid composition of the peptidoglycan, fatty acid methyl esters, respiratory quinones and polar lipids revealed significant differences that, in combination with molecular data, support a dissection of the genus Actinobaculum. The proposals of this study include the reclassification of Actinobaculum schaalii and Actinobaculum urinale as Actinotignum schaalii gen. nov., comb. nov. (type strain DSM 15541(T) = CCUG 27420(T)) and Actinotignum urinale comb. nov. (type strain DSM 15805(T) = CCUG 46093(T)), respectively. Emended descriptions of the genus Actinobaculum and Actinomyces suis are also provided. The results of 16S rRNA gene sequence analysis and DNA-DNA hybridization also indicated that the type strain of Actinobaculum massiliense deposited as CCUG 47753(T) ( = DSM 19118(T)) should in fact be considered a member of the species Actinobaculum schaalii. In addition, comparative 16S rRNA gene sequencing and DNA-DNA relatedness studies of four strains recovered from clinical materials demonstrated that three of the isolates belonged to Actinotignum schaalii; the remaining strain represents a novel species, for which the name Actinotignum sanguinis sp. nov. is proposed. The type strain is IMMIB L-2199(T) ( = DSM 26039(T) = CCUG 64068(T)).