Phenotypic and Genotypic Assays to Evaluate Coagulase-Negative Staphylococci Biofilm Production in Bloodstream Infections.

Coagulase-negative staphylococci (CoNS) are commensal on human body surfaces and, for years, they were not considered a cause of bloodstream infection and were often regarded as contamination. However, the involvement of CoNS in nosocomial infection is increasingly being recognized. The insertion of cannulas and intravascular catheters represents the primary source of CoNS entry into the bloodstream, causing bacteremia and sepsis. They owe their pathogenic role to their ability to produce biofilms on surfaces, such as medical devices. In this study, we evaluate the adhesive capacity of CoNS isolated from blood cultures by comparing a spectrophotometric phenotypic assay with genotypic analysis based on the evidence of the ica operon. We retrospectively reviewed the database of CoNS isolated from blood cultures from January to December 2021 that were considered responsible for 361 bloodstream infections. Eighty-nine CoNS were selected among these. Our data show that Staphylococcus epidermidis was the predominant species isolated, expressing greater adhesive capacities, especially those with the complete operon. Knowledge of the adhesive capabilities of a microorganism responsible for sepsis can be useful in implementing appropriate corrective and preventive measures, since conventional antibiotic therapy cannot effectively eradicate biofilms.

Mycobacterium chimaera Identification Using MALDI-TOF MS Technology: A Practical Approach for the Clinical Microbiology Laboratories.

Mycobacterium chimaera (MC) is an environmental, slowly growing, non-tuberculous mycobacterium (NTM) belonging to Mycobacterium avium complex (MAC), which recently has been linked to severe cardiovascular infections following open heart and vascular surgery. The majority of the diagnostic laboratory tests used in routine are not able to distinguish MC from M. intracellulare (MI), because of the great genetic similarity existing between these two species. The Genotype Mycobacterium NTM-DR™ represents a valid method to differentiate between these species, but it is expensive, requiring also specialized personnel. Recently, MALDI-TOF MS has been proposed to identify relevant NTM. However, a software implementation is required to distinguish between MC and MI, presenting the two microorganisms' overlapping spectra. The present study evaluates the feasibility of applying a MALDI-TOF logarithmic-based analysis in the routine of a clinical microbiology laboratory, and proposes an easy-to-use template spreadsheet to make the results quickly interpretable. The protocol was previously validated through the identification of 87 strains of MC/MI collected from clinical and environmental samples, and it was identified using the GenoType Mycobacterium NTM-DR™ and/or WGS. The proposed protocol provides accurate identification for the isolates tested; moreover, it is less expensive and more rapid than sequencing methods and can be implemented with minimum effort.

Adherence to Guidelines in the Treatment of Diabetic Ketoacidosis in Children: An Austrian Survey.

BACKGROUND: The aim of this study is to assess the adherence of Austrian physicians to International Society for Pediatric and Adolescent Diabetes guidelines 2009 concerning treatment in diabetic ketoacidosis and whether there is a difference between specialty (endocrinologists or intensivists) or clinical experience. PATIENTS AND METHODS: An online questionnaire was sent to members of the working groups of the Austrian Society of Pediatric and Adolescent Medicine. RESULTS: Of 106 questionnaires, 56 were included in the analysis. The mean ± SD overall adherence was 60 ± 23.5%. Endocrinologists showed a nonsignificant higher result, related to a significant higher adherence regarding the amount of fluids (P < 0.05) and tendency to bicarbonate use (P = 0.052) respectively. No differences were found between participants with different clinical experience. All gave crystalloids, 55% administered initial bolus of 10 to 20 mL/kg per hour, 58% used 1.5 to 2 times fluid maintenance, 87% started insulin after first fluid bolus, 28% gave 0.05 and 0.1 IE/kg per hour to infants and children respectively, and 43% 0.05 IE/kg per hour to all patients. When blood glucose falls, 53% gave glucose and 47% reduced insulin. In cerebral edema, 46% gave at least 2 of 3 recommended measures (fluid reduction, mannitol, or hypertonic saline). In acidosis (pH <6.9), 25% administered bicarbonate (as per guideline) and 52.9% never gave bicarbonate. CONCLUSIONS: Adherence to the actual guidelines is 60% and does neither depend on speciality nor on clinical routine. Essential treatment measures (eg, amount of fluids, consequence of rapid glucose fall, bicarbonate use) are not commonly known.

Disseminated Mycobacterium Avium Infection in a Child with Complete Interferon-γ Receptor 1 Deficiency due to Compound Heterozygosis of IFNGR1 for a Subpolymorphic Copy Number Variation and a Novel Splice-Site Variant.

Complete interferon-γ receptor 1 deficiency is a monogenic primary immunodeficiency caused by IFNGR1 germline defects, with autosomal dominant or recessive inheritance, which results in invasive mycobacterial diseases with varying degrees of severity. Most of the autosomal recessive IFNGR1 mutations are homozygous loss-of-function single-nucleotide variants, whereas large genomic deletions and compound heterozygosity have been very rarely reported. Herein we describe the clinical presentation, diagnosis, and successful treatment with hematopoietic stem cell transplantation of a child with disseminated Mycobacterium avium infection due to compound heterozygosity for a subpolymorphic copy number variation and a novel splice-site variant.

Migrations do not modify Mycobacterium tuberculosis resistance rates: a 20-year retrospective study.

Tuberculosis (TB) caused by resistant strains is becoming a public health concern also in high-income countries. In Pavia province, Northern Italy, the prevalence of foreign-born has increased in recent years. Nevertheless, it is unclear if this has modified epidemiology and resistance patterns of Mycobacterium tuberculosis. We retrospectively collected data on all the Mycobacterium tuberculosis strains isolated by culture in the microbiology reference laboratory of the province of Pavia from 01/01/1998 to 31/12/2017. Overall, 919 patients were identified, 320 were foreign-born (34.8%). The proportion of cases due to foreign-born patients increased during the study period as did resistance to isoniazid (INH) (p = 0.01), while resistance to rifampicin (RIF) did not (p = 0.8). INH and RIF resistance were comparable among Italian and foreign-born patients (7.9% vs 9.7% for INH and 4% vs 5% for RIF, respectively). Twenty-height (3.05%) patients harboured MDR strains. Prevalence of MDR strains was not different between Italians and foreign-born patients (2.8% vs 3.4%, p = 0.6). During the study period the proportion of TB cases due to foreign-born patients and INH resistance increased. This increase was equal among Italian and foreign-born patients. Migrants in our area are not a driver of resistance to anti-mycobacterial drugs.

High Prevalence and Incidence of Diabetic Peripheral Neuropathy in Children and Adolescents With Type 1 Diabetes Mellitus: Results From a Five-Year Prospective Cohort Study.

BACKGROUND: In this prospective cohort study, we investigated the prevalence of diabetic peripheral neuropathy at baseline and after five years of follow-up in children and adolescents with type 1 diabetes mellitus using both measurements of nerve conduction velocity and clinical neurological examination. METHODS: A total of 38 patients who underwent insulin pump or intensive insulin therapy were included. The subjects averaged 12.6 ± 2.4 years of age and their diabetes duration averaged 5.6 ± 3.2 years. All patients underwent a detailed physical, neurological, and electrophysiological examination, as well as laboratory testing at their annual checkup. RESULTS: At baseline, the prevalence of diabetic peripheral neuropathy diagnosed using neurological examination was 13.2%, whereas nerve conduction velocity testing revealed diabetic peripheral neuropathy in 31.6%, highlighting a high prevalence of subclinical diabetic peripheral neuropathy. During follow-up, there was a strong increase in the prevalence of clinically diagnosed diabetic peripheral neuropathy, which reached 34.2% (P = 0.039) after five years; the proportion of patients with subclinical diabetic peripheral neuropathy even reached 63.2% (P = 0.002). The most significant changes in electrophysiological parameters were observed in the tibial sensory nerve (P = 0.001). CONCLUSIONS: The prevalence of diabetic peripheral neuropathy in children and adolescents with type 1 diabetes mellitus was high, and there was a rapid increase in the prevalence of diabetic peripheral neuropathy during a five-year follow-up interval. Importantly, our data show that a mere clinical evaluation is not sensitive enough to diagnose diabetic peripheral neuropathy in these patients. Nerve conduction velocity measurement, which is regarded as the gold standard for the assessment of diabetic peripheral neuropathy, should be applied more broadly.

Detection of mcr-4 positive Salmonella enterica serovar Typhimurium in clinical isolates of human origin, Italy, October to November 2016.

In this study we report the detection of the recently described mcr-4 gene in two human isolates of Salmonella enterica serovar Typhimurium. The strains were isolated from faecal samples of two Italian patients with gastroenteritis, collected in 2016. The identified mcr-4 genes (variant mcr-4.2) differed from the mcr-4 gene originally described in a Salmonella strain of swine origin from Italy. Salmonella species could represent a hidden reservoir for mcr genes.

Asaia lannensis bacteremia in a 'needle freak' patient.

The genus Asaia has gained much interest lately owing to constant new species discoveries and its role as a potential opportunistic pathogen to humans. Here we describe a transient bacteremia due to Asaia lannensis in a patient with a psychiatric disorder (compulsive self-injection of different substances). Common phenotypic methods of identification failed to identify this organism, and only restriction fragment lenght polymorphism of PCR-amplified 16S rRNA gene allowed for proper identification. The isolate was highly resistant to most antibiotics. The paper also discusses the currently available medical literature, acknowledges the potential problems linked to the isolation of these strains and proposes an approach to species identification that can be applied in a clinical microbiology laboratory.

Late-onset neonatal group B streptococcal disease associated with breast milk transmission: molecular typing using RAPD-PCR.

Group B Streptococcus (GBS) is considered to be the major cause of neonatal sepsis and meningitis of bacterial origin. Late-onset GBS infection is infrequent and occurs between 1 week and 3 months of age. The transmission of GBS through the ingestion of breast milk is reported in the literature, but only a few of these cases have been confirmed by molecular techniques. In this article we report five cases of late-onset GBS disease: transmission through maternal milk was confirmed in four cases, using the random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) typing assay. In addition, the RAPD-PCR assay showed that each of the isolated clones belonged to a different RAPD genotype, thus revealing that the late-onset GBS infections were not epidemiologically related.

Validity of the neurological examination in diagnosing diabetic peripheral neuropathy.

The aim of this study was to evaluate the prevalence of diabetic peripheral neuropathy in children and adolescents with type 1 diabetes mellitus and examine whether the neurological examination validly diagnoses diabetic peripheral neuropathy as compared with the gold standard of nerve conduction velocity in these patients. Nerve conduction velocity was measured in an unselected consecutive series of patients aged 8-18 years who had been suffering from type 1 diabetes mellitus for at least 1 year. For the neurological examination, neuropathy disability scores and neuropathy sign scores were used. Of the 39 patients, six (15%) had clinically evident diabetic peripheral neuropathy, whereas nerve conduction velocity testing revealed diabetic peripheral neuropathy in 15 (38%) patients. Sensitivity and specificity of the neurological examination for the diagnosis of diabetic peripheral neuropathy were 40% and 100%, respectively. The corresponding positive and negative predictive values were 100% and 72.7%, respectively. This conclusions from this study are that in children and adolescents with type 1 diabetes mellitus, diabetic peripheral neuropathy is highly prevalent, but in the majority of patients it is subclinical. Sensitivity and negative predictive values of the neurological examination are low. Therefore, routine nerve conduction velocity measurement for the assessment of diabetic peripheral neuropathy appears to be warranted in these patients.

Methicillin-resistant Staphylococcus pseudintermedius infection in a bone marrow transplant recipient.

Staphylococcus pseudintermedius is a veterinary pathogen that has seldom been described as an agent of human disease. Features of this probably underreported coagulase-positive Staphylococcus species are depicted here through the description of a graft-versus-host disease-related wound infection caused by a multidrug-resistant strain.

Neonatal diabetes mellitus due to pancreas agenesis: a new case report and review of the literature.

Neonatal diabetes mellitus (NDM) is a rare condition (1:400,000 neonates) defined as hyperglycemia occurring in the first months of life, lasting more than 2 wk and requiring insulin for management. We here report on a 33-month-old girl with pancreatic agenesis, an extremely rare cause of permanent neonatal diabetes mellitus (PNDM). Timely diagnosis and adequate treatment of both endocrine and exocrine insufficiency may permit survival and normal development.

Clonal multidrug-resistant Corynebacterium striatum strains, Italy.

We assessed the clinical relevance and performed molecular characterization of 36 multidrug-resistant strains of Corynebacterium striatum. Pulsed-field gel electrophoresis confirmed a single clone, possessing erm(X), tetA/B, cmxA/B, and aphA1 genes, but few related subclones. This strain is emerging as a pathogen in Italy.

Use of the DiversiLab semiautomated repetitive-sequence-based polymerase chain reaction for epidemiologic analysis on Acinetobacter baumannii isolates in different Italian hospitals.

Acinetobacter baumannii is typically a nosocomial pathogen. Epidemiologic tools that can rapidly trace the spread of hospital-associated infections due to this microorganism are essential. Currently, amplified fragment length polymorphism and pulsed-field gel electrophoresis using ApaI, a macrorestriction enzyme, are the molecular techniques most widely used to type this microorganism. Unfortunately, they are technically demanding, requiring also well-trained personnel, and are time consuming. The aims of this study are 1) to evaluate the usefulness of the semiautomated repetitive-sequence-based polymerase chain reaction (rep-PCR) for typing A. baumannii, comparing this method with another semiautomated technique, such as ribotyping, and 2) to acquire information about the incidence, the clinical significance, and the susceptibility patterns of this microorganism in 13 different Italian hospitals in a 4-week period (total study population, >14000 beds). Twenty-eight A. baumannii were isolated in 7 different hospitals; 21 strains were analyzed with molecular methods. Automated ribotyping distinguished 6 different clusters of isolates, whereas rep-PCR appeared to be more discriminating, allowing us to distinguish 8 different clusters. Our study confirms the good discriminatory power of the semiautomated rep-PCR. Although expensive, this method is simple, fast, and reproducible, and in our opinion, it could be used in a hierarchic approach as a 1st-line typing tool if results of analysis are required in a short period or if a large number of isolates have to be analyzed.