Date Published: June 29, 2017
Publisher: Public Library of Science
Author(s): Hongchao Jiang, Min Su, Liyue Kui, Hailin Huang, Lijuan Qiu, Li Li, Jing Ma, Tingyi Du, Mao Fan, Qiangming Sun, Xiaomei Liu, William M Shafer.
Acute bacterial meningitis is still considered one of the most dangerous infectious diseases in children. To investigate the prevalence and antibiotic resistance profiles of cerebrospinal fluid (CSF) pathogens in children with acute bacterial meningitis in Southwest China, CSF samples from 179 meningitis patients (3 days to 12 years old) with positive culture results were collected from 2012 to 2015. Isolated pathogens were identified using the Vitek-32 system. Gram stain results were used to guide subcultures and susceptibility testing. The antimicrobial susceptibility of isolates was determined using the disc diffusion method. Of the isolates, 50.8% were Gram-positive bacteria, and 49.2% were Gram-negative bacteria. The most prevalent pathogens were E. coli (28.5%), Streptococcus pneumoniae (17.8%), Staphylococcus epidermidis (10.0%), Haemophilus influenzae type b (9.5%), and group B streptococcus (7.2%). In young infants aged ≤3 months, E. coli was the organism most frequently isolated from CSF (39/76; 51.3%), followed by group B streptococcus (13/76; 17.1%) and Streptococcus pneumoniae (8/76; 10.5%). However, in young infants aged >3 months, the most frequently isolated organism was Streptococcus pneumoniae (24/103; 23.3%), followed by Staphylococcus epidermidis (18/103; 17.5%) and Haemophilus influenzae type b (16/103; 15.5%). Antimicrobial susceptibility tests indicated that for E. coli isolates, the susceptibility rates to aminoglycosides ranged from 56.8% to 100.0%, among them, amikacin was identified as the most effective against E. coli. As for cephalosporins, the susceptibility rates ranged from 29.4% to 78.4%, and cefoxitin was identified as the most effective cephalosporin. In addition, the susceptibility rates of piperacillin/tazobactam and imipenem against E. coli were 86.3% and 100%. Meanwhile, the susceptibility rates of Streptococcus pneumoniae isolates to penicillin G, erythromycin, chloramphenicol, ceftriaxone and tetracycline were 68.8%, 0.0%, 87.5%, 81.3% and 0.0%, respectively. Gentamycin, ofloxacin, linezolid and vancomycin were identified as the most effective antibiotics for Streptococcus pneumoniae, each with susceptibility rates of 100%. It was notable that other emerging pathogens, such as Listeria monocytogenes and group D streptococcus, cannot be underestimated in meningitis.
Meningitis is an inflammation of the membranes (meninges) surrounding the brain and spinal cord. Most cases of bacterial meningitis occur during childhood, and acute bacterial meningitis has been found to be a fatal and urgent condition associated with a high rate of mortality and serious potential morbidity [1, 2]. Therefore, early diagnosis and appropriate antibiotic treatment are necessary to avoid further complications. It has been reported that Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b were among the most prevalent pathogens causing this disease [3–6]. However, the prevalence and etiologies of meningitis pathogens may vary during different times, in geographical regions, and according to the age of the patients [3, 7–13]. Moreover, the effectiveness of treatment may be limited due to antibiotic-resistant bacterial strains. Periodic reviews of meningitis cases are necessary.
Acute bacterial meningitis remains a major health problem in children and newborn infants worldwide and, therefore, requires early diagnosis and aggressive therapy [2, 5, 16]. Despite the availability of potent newer antibiotics, the mortality rate associated with acute bacterial meningitis remains very high in some developing countries, ranging from 16–32% [16–20]. Meanwhile, according to the results of extensive studies of the etiology of meningitis that have been conducted in Nepal, French Guiana, the North American Arctic and northern Togo, Streptococcus pneumoniae and Haemophilus influenzae type b were the pathogens most frequently isolated from the CSF of pediatric bacterial meningitis cases [6, 17, 21–23]. Nevertheless, a report from Turkey showed that Neisseria meningitides serogroup W135 was the dominant organism isolated from children with bacterial meningitis . Thus, the etiological pathogens responsible for meningitis have been found to be relatively diverse. In this study, the organisms most frequently isolated from the CSF of meningitis patients in Yunnan province, China during 2012 to 2015 were E. coli (28.5%), Streptococcus pneumoniae (17.8%), Staphylococcus epidermidis (10.0%), Haemophilus influenzae type b (9.5%), and group B streptococcus (7.2%).