Human Campylobacter spp. infections in Italy.

PURPOSE: Campylobacter is a frequent cause of enteric infections with common antimicrobial resistance issues. The most recent reports of campylobacteriosis in Italy include data from 2013 to 2016. We aimed to provide national epidemiological and microbiological data on human Campylobacter infections in Italy during the period 2017-2021. METHODS: Data was collected from 19 Hospitals in 13 Italian Regions. Bacterial identification was performed by mass spectrometry. Antibiograms were determined with Etest or Kirby-Bauer (EUCAST criteria). RESULTS: In total, 5419 isolations of Campylobacter spp. were performed. The most common species were C. jejuni (n = 4535, 83.7%), followed by C. coli (n = 732, 13.5%) and C. fetus (n = 34, 0.6%). The mean age of patients was 34.61 years and 57.1% were males. Outpatients accounted for 54% of the cases detected. Campylobacter were isolated from faeces in 97.3% of cases and in 2.7% from blood. C. fetus was mostly isolated from blood (88.2% of cases). We tested for antimicrobial susceptibility 4627 isolates (85.4%). Resistance to ciprofloxacin and tetracyclines was 75.5% and 54.8%, respectively; resistance to erythromycin was 4.8%; clarithromycin 2% and azithromycin 2%. 50% of C. jejuni and C. coli were resistant to ≥ 2 antibiotics. Over the study period, resistance to ciprofloxacin and tetracyclines significantly decreased (p < 0.005), while resistance to macrolides remained stable. CONCLUSION: Campylobacter resistance to fluoroquinolones and tetracyclines in Italy is decreasing but is still high, while macrolides retain good activity.

Small colony variant of methicillin-resistant Staphylococcus pseudintermedius ST71 presenting as a sticky phenotype.

We first observed the phenomenon of small colony variants (SCVs) in a Staphylococcus pseudintermedius sequence type 71 (ST71) strain, isolated from a non-pet owner. Although we found that small-sized colonies share main features with Staphylococcus aureus SCVs, they nevertheless show a novel, particular, and sticky phenotype, whose expression was extremely stable, even after subcultivation.

Beta-hemolytic, multi-lancefield antigen-agglutinating Enterococcus durans from a pregnant woman, mimicking Streptococcus agalactiae.

A beta-hemolytic Lancefield antigen A-, B-, C-, D-, F-, and G-positive Enterococcus durans strain was cultivated from the rectovaginal swab of a pregnant woman who underwent antenatal screening for Streptococcus agalactiae. The isolate raised concern as to what extent similar strains are misrecognized and lead to false diagnosis of group B streptococci.

Enterococcus hirae: a zoonotic microorganism in human umbilical cord blood.

Enterococcus hirae is rarely collected from man, while it is a common pathogen in mammals and birds. We describe the first isolation of the organism (strain DSM 27815) from human umbilical cord blood (UCB), thus emphasizing the risk of contamination of UCB units for clinical use. In this context, we also highlight the importance of an extensive training of the collecting personnel as to the observance of the disinfection protocol ensuring UCB units sterility.

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.

CAMP test detected Staphylococcus delphini ATCC 49172 beta-haemolysin production.

Through a CAMP test, we first observed a Staphylococcus delphini strain (ATCC 49172) to release beta-haemolysin. Production of the latter in this coagulase-positive species of the 'Staphylococcus intermedius Group', in fact, has been labeled to be undetermined, thus far. Of course, a wider number of strains have to be investigated in order to define whether this property is constitutive (like in Staphylococcus (pseud)intermedius), or strain-dependent (like in Staphylococcus aureus), and which clinical impact it has; nevertheless, we can state that S. delphini ATCC 49172 indeed produces this toxin.

Second Trimester Fetal Loss Due to Citrobacter koseri Infection: A Rare Cause of Preterm Premature Rupture of Membranes (PPROM).

Citrobacter koseri is a facultative anaerobic, motile, non-spore-forming Gram-negative bacillus, which belongs to the family of Enterobacteriaceae. Severe infections due to Citrobacter spp. have been reported in the urinary tract, respiratory airways, intra-abdominal organs, skin and soft tissue, eye, bone, bloodstream, and central nervous system. In newborns, C. koseri is a well-known cause of meningitis, cerebral abscesses, brain adhesions, encephalitis, and pneumocephalus. Infection can be acquired through vertical maternal transmission or horizontal hospital settings; however, in many cases, the source is unknown. Preterm premature rupture of membranes (PPROM), caused by C. koseri, has rarely been described. Herein, we describe a case of PPROM at 16 weeks and 3 days of gestation, leading to anhydramnios. The parents opted for legal termination of the pregnancy, as the prognosis was very poor. C. koseri was isolated postmortem from a placental subamniotic swab and parenchymal sample, as well as fetal blood and lung. To the best of our knowledge, this is the first case of early second-trimester PPROM in which C. koseri infection was demonstrated.

Daptomycin-resistant Staphylococcus pettenkoferi of human origin.

The importance of nosocomial infections caused by coagulase-negative staphylococci is constantly growing. The threat primarily affects immunocompromised patients, the elderly and neonates, particularly after invasive surgery. The problem is fundamentally exacerbated by expanding antibacterial drug resistance. A case report is presented of an 86-year-old patient who underwent a ruptured abdominal aortic aneurysm surgery and developed septicaemia upon surgical wound infection. The causal agent was likely a carbapenem-resistant Klebsiella pneumoniae, however, daptomycin-resistant Staphylococcus pettenkoferi was identified in blood cultures in the absence of daptomycin treatment. To the authors' knowledge, the case study presented is the first published episode of daptomycin-resistant S. pettenkoferi strain.

Could ß-hemolytic, group B Enterococcus faecalis be mistaken for Streptococcus agalactiae?

A ß-hemolytic Enterococcus faecalis strain agglutinating Lancefield group A, B, C, D, F, and G antisera was observed from a rectovaginal swab, in the context of antenatal screening for Streptococcus agalactiae (group B Streptococcus [GBS]). This is the first multi-Lancefield antisera-agglutinating isolate of this species, and it raised particular concern, as it may mimic GBS, leading to false reporting and useless receipt of intrapartum antibiotics.

Staphylococcus pseudintermedius for CAMP-test.

CAMP test reliably detects Listeria monocytogenes (Lm) and Streptococcus agalactiae (group B streptococcus, GBS); it is traditionally performed streaking the tested isolate perpendicularly to Staphylococcus aureus (Sa), provided that reference Sa strains (that produce ß-hemolysin) are used. In a zone of ß-hemolysin activity, in fact, GBS and Lm form typical arrow-shaped hemolytic areas. While Sa production of the toxin is strain-dependent, however, that of Staphylococcus pseudintermedius (Sp), a pet-owner colonizer and an emerging human pathogen, is constitutive, then observed in all clinical isolates. Therefore, Sp may indeed represent a valid alternative to perform the assay.

Liofilchem(®) Chromatic VRE and vancomycin MIC Test Strip detected glycopeptide resistance in a vanB neonatal Enterococcus faecium isolate showing alternate vancomycin susceptibility and resistance with bioMérieux Vitek2.

A 1-month old neonate urine sample yielded vanB Enterococcus faecium; nevertheless, the isolate alternatively showed susceptibility and resistance to vancomycin with bioMérieux Vitek2 (cards AST592, AST632, AST586), while glycopeptide resistance was detected by Liofilchem(®) vancomycin MIC Test Strip and disc along with the Chromatic VRE chromogenic medium. This communication emphasizes that, as vanB gene may be heterogeneously expressed within a given Enterococcus population, glycopeptide resistance may be missed when using automated systems for antibiotic susceptibility testing. We suggest therefore that vancomycin in vitro activity be studied on all clinical isolates through agar methods, including use of chromogenic media.

Surgical wound infection by mannitol-nonfermenting Staphylococcus aureus after lumbar microdiscectomy.

Purulent infection of a surgical wound developed after discectomy, and a mannitol-nonfermenting Staphylococcus aureus isolate was cultivated as the etiologic agent. Nonfermenting S. aureus strains are exceedingly rare and may be erroneously mistaken and dismissed as contaminants. This report then emphasizes that pure and massive cultures must be carefully evaluated, even if preliminary examination does not suggest a pathogenic organism. Also, although mannitol-negative, the studied strain was correctly detected as S. aureus by both the-FISH test (AdvanDx, USA) and the Liofilchem 'Chromatic Staph aureus', highlighting that additional diagnostic methods may support recognition of uncommon, nonfermenting S. aureus strains in the daily practice.

Successful off-label use of the Cepheid Xpert GBS in a late-onset neonatal meningitis by Streptococcus agalactiae.

We report the case of a late-onset neonatal meningitis by Streptococcus agalactiae (group B Streptococcus - GBS) that was diagnosed with a latex agglutination assay (on cerebrospinal fluid, CSF), as well as by using, for the first time, Xpert GBS (Cepheid, US) on CSF. Due to empirical antibiotics given before sampling, both CSF and blood culture were negative, so the abovementioned diagnostics was crucial. Moreover, the Xpert GBS assay, performed according to an off-label, modified protocol (the system is designed for GBS-carriage intrapartum screening, based on a completely automated real time-Polymerase Chain Reaction) quickly detected the organism's genome target. Although further investigation on this test's performace on CSF is required, then, we trust it may be a promising, quick and precise diagnostic method for infections in newborns.

Liofilchem(®) O.A. Listeria agar and direct CAMP test provided sooner Listeria monocytogenes identification from neonatal bacteremia.

Listeria monocytogenes infection in pregnant women and newborns is a cause for serious concern, and invasive disease outcome strongly depends on prompt antibiotic therapy. To provide sooner identification from neonatal bacteremia we performed a CAMP test directly on positive blood aliquots and inoculated the Liofilchem(®) O.A. Listeria chromogenic agar as well, thus providing a 24-h turn-around time for response.

Streptococcus agalactiae vaginitis: nonhemolytic variant on the Liofilchem® Chromatic StreptoB.

Streptococcus agalactiae (group B Streptococcus, GBS) vaginal pathogenicity is not uniformly acknowledged throughout the literature; accordingly, in women, genital itching and burning, along with leukorrhea are commonly and almost exclusively referred to bacterial vaginosis, candidiasis and trichomoniasis. Conversely, GBS virulence for vagina was recognized in the past, as the organism has been observed to potentially cause local inflammation and discharge, as well as lactobacilli rarefaction. We depict here a case where a nonhemolytic (γ-hemolytic) GBS strain was found to be the etiologic agent of vaginal infection. Such uncommon S. agalactiae phenotypes are hard to be recognized and may be therefore responsible for misdiagnosing and underestimation of GBS vaginitis prevalence; here, we had the support of the Liofilchem(®) Chromatic StreptoB medium, that successfully detected such an atypical variant.

About a bloodstream Corynebacterium striatum isolate.

Corynebacterium striatum is often dismissed as a contaminant when cultivated from blood samples; indeed, it is a skin saprophyte that may therefore be introduced into the clinical specimen accidentally. Nevertheless, the organism can be responsible for true bacteraemias, and multidrug resistance spread among nosocomial strains is of increasing concern. Specific criteria for testing have not been defined yet, but we however suggest to report clear resistances (i.e. absence of any inhibition zones with the disc test), in order to try to understand this species behaviour under antibiotic exposure. In this context, features of a blood isolate (strain DSM 45711) are here depicted.