Serotype distribution of Streptococcus pneumoniae in children with invasive diseases in Turkey: 2008-2014

Successful vaccination policies for protection from invasive pneumococcal diseases (IPD) dependent on determination of the exact serotype distribution in each country. We aimed to identify serotypes of pneumococcal strains causing IPD in children in Turkey and emphasize the change in the serotypes before and after vaccination with 7-valent pneumococcal conjugate vaccine (PCV-7) was included and PCV-13 was newly changed in Turkish National Immunization Program. Streptococcus pneumoniae strains were isolated at 22 different hospitals of Turkey, which provide healthcare services to approximately 65% of the Turkish population. Of the 335 diagnosed cases with S. pneumoniae over the whole period of 2008-2014, the most common vaccine serotypes were 19F (15.8%), 6B (5.9%), 14 (5.9%), and 3 (5.9%). During the first 5 y of age, which is the target population for vaccination, the potential serotype coverage ranged from 57.5 % to 36.8%, from 65.0% to 44.7%, and from 77.4% to 60.5% for PCV-7, PCV-10, and PCV-13 in 2008-2014, respectively. The ratio of non-vaccine serotypes was 27.2% in 2008-2010 whereas was 37.6% in 2011-2014 (p=0.045). S. penumoniae serotypes was less non-susceptible to penicillin as compared to our previous results (33.7 vs 16.5 %, p=0.001). The reduction of those serotype coverage in years may be attributed to increasing vaccinated children in Turkey and the increasing non-vaccine serotype may be explained by serotype replacement. Our ongoing IPD surveillance is a significant source of information for the decision-making processes on pneumococcal vaccination.

[Evaluating of Plasmodium species isolated from peripheral blood samples in a non-endemic region]

OBJECTIVE

Malaria is a parasitic disease, caused by Plasmodium species, which transmitted to humans through genus Anopheles mosquitoes. This disease widely spreaded in tropical and subtropical areas. The aim of our study is to evaluate malaria cases diagnosed by peripheral blood examination.

METHODS

Peripheral blood samples sent to Parasitology Laboratory between 2001 and 2013 years, were examined using thick and thin blood smear techniques.

RESULTS

A total of 102 blood samples obtained from suspected patients were examined and eight of them were found to be positive. All cases were male and Plasmodium falciparum and Plasmodium vivax was detected in seven (87.5%) and one (12.5%) of them, respectively. Blood samples were mainly sent from Departments of Infectious Diseases. All P. falciparum cases had a history about work or travel to different African countries.

CONCLUSION

We think that patients who has fever and travel history to endemic countries especially in Africa, blood examination for malaria parasites should be taken into account in differential diagnosis.

Panton-Valentine leukocidin positive Staphylococcus aureus infection in childhood: a case report

Staphylococcus aureus is a common cause of musculoskeletal infections. Panton-Valentine leukocidin (PVL) is an exotoxin produced by S. aureus and is an important virulence factor. PVL-positive S. aureus infections have been associated with soft tissue infections and necrotizing pneumonia. In this case report, the clinical course of a 13-year-old boy who was admitted with right hip pain and fever, diagnosed with a gluteal abscess and incidentally discovered multiple cavitary pulmonary lesions, and had a methicillin susceptible and PVL-producing S. aureus (MSSA) extracted from the abscess culture is presented. The related literature is also reviewed.

[Investigation of the presence of class 1, 2, 3 integrons and their relationships with antibiotic resistance in clinical Stenotrophomonas maltophilia isolates]

Stenotrophomonas maltophilia is an opportunistic emergent pathogen causing hospital-acquired infections. It is resistant to majority of the broad spectrum antibiotics due to several mechanisms which significantly limit the treatment options. Although the relationship between integrons, mobile genetic elements which play role in transferring resistance genes, and the antibiotic resistance in different gram-negative bacteria have been investigated, the data are limited in Turkey especially for S.maltophilia. The aims of this study were to detect the presence of different classes of integrons and plasmids in clinical isolates of S.maltophilia and to investigate the antibiotic resistance profiles of those isolates. One hundred S.maltophilia strains isolated from various clinical samples (32 sputum, 25 tracheal aspirates, 9 urine and blood, 7 exudates and catheters, 4 sterile body fluids and wounds, 2 CSF, 1 conjunctiva) in our microbiology laboratory during January 2011-September 2012, were included in the study. The isolates were identified by VITEK2 Compact (BioMerieux, France) or Phoenix 100 (BD, USA) automatized systems, and the susceptibilities of the strains to levofloxacin, chloramphenicol, ceftazidime and trimethoprim/sulfamethoxazol (SXT) were evaluated via broth microdilution method according to the CLSI recommendations. Class 1 (intI-1), class 2 (intI-2), class 3 (intI-3) integron gene cassettes and integron 5'-3' conserved gene regions (intI-5'-3'CS) were investigated by polymerase chain reaction (PCR) using specific primers in all of the strains. Nucleotide sequence analysis of PCR products was performed in case of positive result, and the presence and size of plasmids were further investigated. The susceptibility rates of S.maltophilia strains to ceftazidime, chloramphenicol, SXT and levofloxacin were found as 24%, 66%, 93% and 95%, respectively, while MIC(50) and MIC(90) values were 64-128 µg/ml, 8-16 µg/ml, 1/19-2/38 µg/ml and 1-2 µg/ml, respectively. In PCR amplification with intI-1, intI-2 and intI-3 primers, 12%, 2% and 10% of the isolates yielded expectative bands, respectively. DNA sequence analysis of the amplified products revealed five isolates to harbour intI-1 gene, while intI class 2 and class 3 genes were not detected in any of the strains. Furthermore in PCR amplification with intI-5'CS and 3'CS primers, 20% of the strains yielded expected bands. Sequence analysis of these amplicons revealed the presence of quaternary ammonium compound resistance protein genes (qacL) in two, aminoglycoside adenyltransferase gene (aadA) in one and integron-associated recombination site (attI1) genes in five strains. Additionally, the presence of plasmids have been detected in 9 (9%) of the strains, however all of them was integron-negative. The sizes of plasmids were 2340, 1350, 2760, 18600, 20000, 3570-2540, 2510 and 5000-2540 base pairs, respectively. When the antibiotic susceptibility patterns of strains were compared with the presence of intI gene regions, no statistically significant relationship was observed (p> 0.05). In conclusion, the demonstration of integron class 1 genes and plasmids among clinical S.maltophilia strains is regarded as a warning data to indicate the potential for spread of those resistant strains in our hospital.

Evaluation of childhood brucellosis in the central Black Sea region

Brucellosis is a systemic infectious disease that leads to various clinical pictures and is still a significant health problem in Turkey. In this study, 52 pediatric patients diagnosed with brucellosis between January 2008 and December 2013 were examined. Clinical and laboratory findings, response to treatment, prognosis and complications were evaluated. Diagnosis of brucellosis was made based on a clinical picture compatible with the disease, together with standard tube agglutination test (SAT) positivity (1/160 or higer titer) or isolation of Brucella spp. in a sterile body fluid culture. The cases comprised 10 females and 42 males. In 75% of cases, there was a history of consumption of unpasteurized milk or dairy products. The most commonly seen symptoms and findings were fever (75%), arthralgia (54%), fatigue (19%), splenomegaly (44%), hepatomegaly (42%) and arthritis (19%). Atypical presentations were seen in one case of epidydymo-orchitis and three cases of bleeding of the nose and gums. In the laboratory examinations, anemia was determined in 56% of cases, leukopenia in 40% and thrombocytopenia in 27%. In blood cultures taken from 41 patients, Brucella spp. were isolated in 23 (56.1%). All patients recovered, and sequelae were seen only in a patient with osteoarthritis. In conclusion, although brucellosis leads to many different clinical pictures, a very good response to treatment can be obtained. If effective treatment cannot be implemented in time, the disease may become chronic, and complications and relapses may be encountered. Therefore, early diagnosis and treatment is of great importance.

[Seasonal and regional distribution of tularemia cases in Amasya, Turkey]

Tularemia have attracted attention due to increased number of cases since 2009 in Amasya region which is located at Central Blacksea Region of Turkey. The aims of this letter were to provide information about the disease, to emphasize the importance of early treatment due to the outbreak peak in our province between 2009-2012 and water chlorination in epidemic areas. A total of 250 tularemia-suspected patients (117 female, 133 male; mean age: 42 yrs) who were admitted to our hospital with the symptoms of sore throat, fever, malaise and/or presence of neck mass, from 20 different locations within last four years were included in the study. Serum samples of 73 (29.2%) patients yielded ≥ 1/160 titers with F.tularensis microagglutination test which were considered as positive. All positive cases presented with the oropharyngeal form of the disease. The year with the highest number of tularemia cases was 2010. When the regional distribution was evaluated, it was detected that positive cases have precipitated especially in the southeastern (highland area) and northeastern (lowland area) parts of Amasya (34/73; 46.6%). Majority of the tularemia cases (53/73; 72.6%) were identified in colder seasons. The number of cases in rural and urban centers have decreased after 2010. In conclusion, it is considered that the emergence of new cases is likely to persist due to the geographical characteristics of Amasya and occupational properties (livestock breeding) of the population. Therefore, the clinicians should consider tularemia in differential diagnosis of the cases originated from risky rural areas.

Panton-Valentine leukocidin in community and hospital-acquired Staphylococcus aureus strains

Staphylococcus aureus causes serious hospital-acquired (HA) and community-acquired (CA) infections. Skin and soft-tissue infections especially are sometimes caused by strains harbouring Panton-Valentine leukocidin (PVL). PVL belongs to a family of bi-component leukocidal toxins produced by staphylococci. It is a pore-forming toxin encoded by lukF-PV and lukS-PV. A total of 70 S. aureus strains: 38 (54%) methicillin-resistant (MRSA) and 32 (46%) methicillin-susceptible (MSSA), were isolated from patients admitted to Dicle University Hospital (Turkey). Identification of S. aureus and antibiotics-susceptibility testing were performed with PHOENIX 100. PVL genes and mecA genes were detected by polymerase chain reaction. Of the 70 studied strains, 36 ones (51%) were community acquired and 34 ones (49%) were hospital acquired . A total of 38 (54%) strains were positive for mecA (mecA⁺), of which 32 ones (84%) were HA. Of the mecA⁻ strains, 30 (94%) were CA. Of the 70 studied strains, 12 (17%) strains were PVL⁺: 8 (22%) of the 36 CA strains and 4 (12%) of the 34 HA strains. Of the 12 PVL⁺ strains, 4 strains were mecA⁺. The PVL positivity rate was 25% in MSSA, whereas 10.5% in MRSA. Of the overall PVL⁺ strains, seven strains were obtained from wounds; four ones from skin abscess; and one from blood culture. Taken together, the obtained results showed a substantial level of PVL genes in the studied region. Although PVL is known as a common virulence factor of CA MRSA, HA MRSA isolates in our study showed a considerable rate of PVL positivity.

[Strongyloides stercoralis in a patient with ankylosing spondylitis: case report]

Strongyloidiasis is a nematode-borne disease caused by several Strongyloides species. This case was presented in order to indicate Strongyloidosis in immunocompromised patients with several clinical findings. A fifty-five year old male patient on corticosteroid medication for a long time because of ankylosing spondylitis was on infliximab medication for 5 years. He presented with swelling of his right foot for ten days, right shoulder stiffness and low back pain. The presence of anaemia was remarkable. S. stercoralis was reported in histological examination of endoscopic duodenal biopsy specimen. Peripheral blood smear showed 68.4% neutrophils, 17% lymphocytes, 7.5% monocytes, and 6.7% (normal range 2%-6.2) eosinophils. The level of IgE was raised: 285IU/mL (normal range 5-120IU/mL). A large number of S. stercoralis larvae were detected upon stool examination with saline and iodine mounts and the formaldehyde ether concentration method. After treatment with two cure albendazole 400 mg/day for 7 days, S. stercoralis larvae were not detected in stool examination. It is interesting that response to treatment was not observed on the first cure and the recovery was seen on the second cure. We suggest that hyperinfections should be taken into consideration in the diagnosis and treatment of immunocompromised patients with several complaints so that life-threatening effects of the nematode may be prevented.

[Investigation of the presence of New Delhi metallo-beta-lactamase-1 (NDM-1) by PCR in carbapenem-resistant gram-negative isolates]

Bacteria producing New Delhi metallo-beta-lactamase-1 (NDM-1) exhibit high level resistance to beta-lactams including carbapenems. This broad-spectrum resistance limits treatment options for infections caused by NDM-1 producers. NDM-1 was first isolated from an Indian patient in Sweden; since then, NDM-1 producing isolates have been identified in many countries including Turkey. In this study, we investigated the presence of NDM-1 by PCR method in various gram-negative isolates recovered from clinical specimens in tertiary care hospitals in Samsun, Turkey. A total of 210 carbapenem-resistant gram-negative isolates (132 Acinetobacter baumannii, 54 Pseudomonas aeruginosa, 5 Pseudomonas putida, 8 Enterobacter cloacae, 3 Enterobacter aerogenes, 3 Klebsiella pneumoniae, 2 Providencia rettgeri, 2 Escherichia coli and 1 Citrobacter freundii) were included in the study. Identification and antibiotic susceptibility testing of the isolates were performed by using Vitek-2 Compact (bioMerieux, France) and BD Phoenix (BD Diagnostic Systems, MD) automated systems. The results of antibiotic susceptibility testing were interpreted according to the CLSI recommendations. In our study, NDM-1 gene was not detected in any of the clinical isolates by PCR. There was only one case study that reported the presence of NDM-1 in clinical isolates from Turkey [Poirel L et al. Antimicrob Agents Chemother 2012;56:2784]. Our data, together with the others, indicated that the existence of NDM-1 in clinical isolates is not common in Turkey. However, since NDM-1 is a plasmid-encoded enzyme, there is always a risk of spread of this resistance through the bacterial strains in our country. Therefore, continuous surveillance and investigation of carbapenem-resistant isolates with resistance patterns suggestive of NDM-1 may enable to identify NDM-1 producing isolates. Meanwhile special care should be given on rational antibiotic use and establishment of appropriate infection control policies to prevent the spread of NDM-1 producers and other potential resistant strains.

[In vitro activity of ceftaroline to MRSA isolates: a multicenter study]

Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging pathogen that cause severe community- and hospital-acquired infections. Studies continue on searching alternatives due to the limited number of therapeutic options in MRSA infections. Ceftaroline is a wide-spectrum new generation cephalosporin which has been begun to be used in treatment of skin and respiratory tract infections caused by MRSA. The aim of this study was to investigate the in vitro activity of ceftaroline against MRSA strains isolated from various clinical specimens in microbiology laboratories of seven hospitals located at different provinces (Bolu, Samsun, Rize, Tekirdag, Sakarya, Amasya, Osmaniye) of Turkey. A total of 192 MRSA isolates (89 skin/wound/abscess, 38 blood, 36 respiratory tract, 29 urine/sterile body fluids/catheter) were included in the study, and ceftaroline susceptibilities of the strains were detected by broth microdilution method. MIC values of 181 (94.3%) isolates were determined as ≤ 1 µg/ml meaning of susceptible according to the criteria of CLSI, and MIC values of 11 (5.7%) isolates were found as 2 µg/mL indicating intermediate susceptibility. The range of MIC values of the isolates was found between 0.25-2 µg/ml. The rates of intermediate isolates have varied between 0-12.5% from the participating centers. MIC50 and MIC90 values of all the isolates were determined as 0.5 µg/ml and 1 µg/ml, respectively. No significant differences were found between the centers in terms of mean MIC values (p> 0.05). MIC50 and MIC90 values in Samsun and Bolu isolates were found to be the same with the whole group, however, MIC50 and MIC90 were 0.5 µg/ml and 0.5 µg/ml in Amasya isolates and 1 µg/ml and 1 µg/ml in Rize, Tekirdag, Osmaniye and Sakarya isolates, respectively. When evaluating MIC50 and MIC90 values and isolation rates of intermediate strains according to the specimen types, there were no significant differences (p> 0.05). Susceptibility rates to ceftaroline and the distribution profiles of MIC values of the isolates obtained from seven centers of Turkey have been detected similar with the previous American and European reports. With this study, initial data on the activity of ceftaroline against MRSA were obtained from Turkey. These preliminary findings indicate that ceftaroline is effective even on Turkish isolates and can be a suitable treatment in cases requiring wide-spectrum antimicrobiotic use, however further large-scaled studies are needed.