Rhamnolipid-Coated Iron Oxide Nanoparticles as a Novel Multitarget Candidate against Major Foodborne E. coli Serotypes and Methicillin-Resistant S. aureus.

Surface-growing antibiotic-resistant pathogenic bacteria such as Escherichia coli and Staphylococcus aureus are emerging as a global health challenge due to dilemmas in clinical treatment. Furthermore, their pathogenesis, including increasingly serious antimicrobial resistance and biofilm formation, makes them challenging to treat by conventional therapy. Therefore, the development of novel antivirulence strategies will undoubtedly provide a path forward in combatting these resistant bacterial infections. In this regard, we developed novel biosurfactant-coated nanoparticles to combine the antiadhesive/antibiofilm properties of rhamnolipid (RHL)-coated Fe3O4 nanoparticles (NPs) with each of the p-coumaric acid (p-CoA) and gallic acid (GA) antimicrobial drugs by using the most available polymer common coatings (PVA) to expand the range of effective antibacterial drugs, as well as a mechanism for their synergistic effect via a simple method of preparation. Mechanistically, the average size of bare Fe3O4 NPs was ~15 nm, while RHL-coated Fe3O4@PVA@p-CoA/GA was about ~254 nm, with a drop in zeta potential from -18.7 mV to -34.3 mV, which helped increase stability. Our data show that RHL-Fe3O4@PVA@p-CoA/GA biosurfactant NPs can remarkably interfere with bacterial growth and significantly inhibited biofilm formation to more than 50% via downregulating IcaABCD and CsgBAC operons, which are responsible for slime layer formation and curli fimbriae production in S. aureus and E. coli, respectively. The novelty regarding the activity of RHL-Fe3O4@PVA@p-CoA/GA biosurfactant NPs reveals their potential effect as an alternative multitarget antivirulence candidate to minimize infection severity by inhibiting biofilm development. Therefore, they could be used in antibacterial coatings and wound dressings in the future. IMPORTANCE Antimicrobial resistance poses a great threat and challenge to humanity. Therefore, the search for alternative ways to target and eliminate microbes from plant, animal, and marine microorganisms is one of the world's concerns today. Furthermore, the extraordinary capacity of S. aureus and E. coli to resist standard antibacterial drugs is the dilemma of all currently used remedies. Methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) have become widespread, leading to no remedies being able to treat these threatening pathogens. The most widely recognized serotypes that cause severe foodborne illness are E. coli O157:H7, O26:H11, and O78:H10, and they display increasing antimicrobial resistance rates. Therefore, there is an urgent need for an effective therapy that has dual action to inhibit biofilm formation and decrease bacterial growth. In this study, the synthesized RHL-Fe3O4@PVA@p-CoA/GA biosurfactant NPs have interesting properties, making them excellent candidates for targeted drug delivery by inhibiting bacterial growth and downregulating biofilm-associated IcaABCD and CsgBAC gene loci.

The prevalence of healthcare-associated infection in medical intensive care units in Tunisia. Results of the multi-centre nosorea1 study.

OBJECTIVES: To determine the prevalence of Healthcare-Associated Infection (HAI) in medical Intensive Care Unit (ICU), risk factors for these infections and identify the predominant infecting organisms. METHODS: A 1-day point-prevalence study within all medical ICUs in Tunisia, all patients occupying an ICU bed over a 48-hour period were included. Rates of HAI, resistance patterns of microbiological isolates and potential risk factors for HAI were recorded. RESULTS: One hundred and three patients were collected from 15 Tunisian medical ICUs. HAI prevalence was 25.2% CI 95% [15-35].The most frequent HAIs were hospital acquired pneumonia in 19 cases (59%) and catheter related infection in 5 cases (15%). Independent factors associated with HAI occurrence were SAPSII score ≥ 33 with OR 1.047; CI 95% [1.015-1.077], p=0.003 and recent hospitalization with OR 4.14 CI 95% [1.235-13.889], p=0.021. Non-fermenting pathogens were the most frequent microorganisms reported in ICUs ecology, prior colonization and HAIs of the screened patients. CONCLUSION: HAIs are frequent in medical ICUs in Tunisia, which emphasize the importance of specific measures for surveillance and infection control in critically ill patients. Implementing a national monitoring system of HAI should be a major priority of public health in Tunisia.

[Prenatal diagnosis and management of two cases of bilateral ureteroceles on simplex ureters]. / Diagnostic prénatal et prise en charge de deux cas d'urétérocèles bilatéraux sur uretères simplex.

Ureterocele is a rare urologic disorder characterized by pseudocystic dilatation of the terminal submucosal ureter. Most cases of ureteroceles are associated with complete ureteral duplicity and ureterohydronephrosis, whereas ureteroceles on simplex ureters are rarer. The authors report two cases of bilateral ureteroceles on simplex ureters diagnosed prenatally at 30 and 32weeks gestation. Fetal ultrasound had revealed bilateral ureterohydronephrosis. The delivery was made at term and renal function was normal at birth. Radiological and isotopic studies of the urinary tract confirmed the diagnosis of bilateral ureteroceles on simplex ureters that were obstructive in one case and not obstructive in the other case. Both cases had urinary antiseptic treatment and neither had urinary infection. Endoscopic puncture with electrocoagulation of ureteroceles was performed at 8 and 14months of age, respectively, with a simple postoperative course. Prenatal diagnosis of ureteroceles is essential to plan early multidisciplinary care to avoid long-term renal consequences.

[Neonatal expression of beta-thalassemia trait associated with hereditary spherocytosis in two monozygotic twins]. / Expression néonatale d'un trait bêta-thalassémique associé à une sphérocytose héréditaire chez deux jumelles monozygotes.

The beta-thalassemia trait is a heterozygous beta-thalassemia characterized by a partial deficiency of the synthesis of beta-globin chains of hemoglobin. It is usually asymptomatic and the diagnosis is often made on the occasion of the completion of a systematic blood count or a family survey. Clinical expression during the neonatal period is impossible and its association with hereditary spherocytosis is common. We report two monozygotic twins who, on the 3rd day of life, presented intense jaundice, unconjugated bilirubin associated with anemia, without hepatosplenomegaly. Laboratory tests found nonimmune hemolytic anemia with microcytosis and hypochromia justifying iterative blood transfusions. The etiological investigation found heterozygous beta-thalassemia associated with hereditary spherocytosis. The family investigation and molecular analysis objectified the beta-thalassemic mutation IVS1nt110 (G→A) in the heterozygous state in the twins, the father, the mother, and in one of the two brothers. With any nonimmune hemolytic anemia in newborns, the etiological investigation should be systematic for early diagnosis and to plan appropriate treatment.

[Spontaneous rupture of the imperforate hymen in two newborns]. / Rupture spontanée de l'imperforation de l'hymen chez deux nouveau-nés.

Imperforate hymen is the most frequent congenital malformation of the female genital tract and usually remains asymptomatic until puberty. The diagnosis of this malformation is rarely made at birth and surgical treatment is often by hymenotomy. However, spontaneous rupture of the imperforate hymen is possible but is very rare. We report two cases of imperforate hymen revealed by mucocolpos at birth. Ultrasound examination does not objectify hydrocolpos or hydrometrocolpos. Spontaneous rupture of the imperforate hymen was observed respectively in the 4th and 7th day of life with a satisfactory result at 1 month of age. Screening for the imperforate hymen must be systematic at birth to offer early hymenotomy if the spontaneous rupture is not adequate and prevent serious complications of the disease at puberty.

[Prenatal diagnosis of a giant cystic lymphangioma in the axillothoracic wall]. / Diagnostic anténatal d'un lymphangiome kystique géant de la paroi thoraco-axillaire.

Cystic lymphangiomas are benign malformative tumors of the lymphatic vessels, rare but potentially serious and usually located in the cervical region. The diagnosis is usually easy, but the treatment is sometimes difficult because of their location and extension into the surrounding tissue. We report a case of giant cystic lymphangioma of the right axillary-thoracic wall diagnosed by prenatal ultrasound at 20 weeks gestation. The male infant was born at 37 weeks gestation with a large, swelling, lateral parietal right chest. Ultrasound soft tissue and chest CT scan confirmed the diagnosis of giant cystic lymphangioma of the right axillary-thoracic wall. Surgical excision was performed on the 21st day after birth and the mass was excised incompletely. The postoperative course was uncomplicated. Ultrasound soft tissue follow-up showed the persistence of multiple cystic structures in the axilla. Prenatal diagnosis of these tumors is essential for planning multidisciplinary management in early postnatal care.

[Clinical outcome and prognosis of neonatal bacterial meningitis]. / Aspects cliniques et évolutifs des méningites bactériennes néonatales.

OBJECTIVES: To study the epidemiological, clinical, and bacteriological aspects as well as the outcome of neonatal bacterial meningitis and analyze the factors of poor prognosis of this condition. PATIENTS AND METHODS: We report a retrospective analysis of 44 cases of neonatal bacterial meningitis hospitalized in the pediatric unit of Tahar Sfar Hospital in Mahdia, Tunisia, between January 1996 and December 2010. Inclusion criteria were infants less than 29 days of age who were hospitalized for bacterial meningitis diagnosed on either the presence of bacteria in cerebrospinal fluid or with more than 50 cells/mm(3), predominance of neutrophils, and the protein level greater than 1.2g/l. Clinical data were obtained through the analysis of patient files. Statistical analysis was based on the Chi(2) test, and P-values less than 0.05 were considered statistically significant. RESULTS: The incidence of neonatal bacterial meningitis was 0.49 per 1000 live births. The patients were premature in 20.4 % and low birth weight in 13.6 % of cases. The clinical presentation was not specific for most cases. The main signs at admission were hyperthermia (43.2 %), refusal to nurse (20.4 %), seizures (18.2 %), and respiratory distress (13.6 %). The cerebrospinal fluid culture was positive in 36.4 % of cases. The group B streptococcus was the most frequently isolated (62.5 %) followed by Escherichia coli (12.5 %). The association of cefotaxime-ampicillin-gentamicin was used as the first treatment in all cases. Ofloxacin was associated with initial antibiotic therapy during the first 5 days in 20.4 % of cases. The mortality rate was 15.9 % and the rate of neurological sequelae in survivors was 21.6 %. Prematurity, low birth weight, shock, respiratory distress, and pleocytosis of less than 500 cells/mm(3) were the main factors of a poor prognosis. The addition of ofloxacin to the initial antibiotic therapy was associated with a decreased rate of neurological sequelae in survivors (11 % vs. 25 %, P=0.042). CONCLUSION: This study emphasizes the severity of neonatal bacterial meningitis with high rates of mortality and neurological sequelae, especially in premature and low birth weight infants. An early diagnosis and effective antibiotic therapy is needed to improve the prognosis.

[Neonatal renal vein thrombosis in a heterozygous carrier of both factor V Leiden and the MTHFR gene mutation]. / Thrombose néonatale de la veine rénale et double hétérozygotie pour la mutation du facteur V de Leiden et du gène de la MTHFR.

Renal vein thrombosis (RVT) is a rare but potentially serious neonatal disease. Its epidemiology and its clinical and biological expression are currently well known, but its etiological exploration, like that of venous thromboembolism, is increasingly complex. Perinatal risk factors such as prematurity, dehydration, and birth asphyxia have lost their direct accountability at the expense of their interaction with constitutional disorders of hemostasis. We report a case of RVT in a newborn who was a heterozygous carrier of both factor V Leiden and the methylene tetrahydrofolate reductase (MTHFR) gene mutation. We recall the clinical and epidemiological characteristics. A search for inborn blood coagulation disorders should be systematic in the newborn infant with venous thrombosis because of the risk of recurrence, taking into account perinatal factors and maternal thrombophilia (especially if RVT is established during the prenatal period).

[Spontaneous regression of a giant facial hemangioma]. / Régression spontanée d'un hémangiome géant de la face.

Infantile cutaneous hemangioma is a benign vascular tumor and is very frequent in infants. The evolution is mostly favorable with spontaneous regression in 80% of cases. Clinical diagnosis is easy in its triphasic typical form with a phase of sometimes brutal postnatal growth, a phase of stabilization and a phase of slow secondary regression. We report a case of a giant facial hemangioma diagnosed at birth in full-term female newborn getting the right peri-orbital and fronto-temporal region. Initial evolution was marked by a fast increase of the tumor justifying its stake under prednisone at the age of 3 months but without improvement. At the age of 6 months, the patient was hospitalized for infection of the hemangioma with favorable evolution under oxacilline. Following evolution was marked by the total regression of the hemangioma at the age of 5 years at the price of peri-orbital cutaneous scars. We discuss here the diagnostic, therapeutic and evolutionary aspects of this pathology and review of the literature.