Bacteriological investigations were carried out on 151 children (80 males and

71 females) suffering from acute respiratory infections (ARI) to And out bacteria

associated with ARI. Fifty one children presenting with upper respiratory infections

(URI) and 100 with lower respiratory infections (LRI) seen at the outpatient

department of the Institute of Child Health and Hospital for Children, Madras,

were included in this study. In all, 56% of the children yielded any one

or a mixture of bacteria that could be potential or probable pathogens of ARI.

Nonfermenting gram negative bacilli (NFGNB) were the predominant organisms

isolated (27%) followed by non-typable ampicillin resistant Haemophilus influenzae

(13%) and b.  haemolytic streptococci groups C and G (11%). The other bacteria

isolated in this study were Klebsiella pneumoniae (7%), Streptococcus pneumoniae

(3%), Neisseria sps. pure (3%) and Staphylococcus aureus (1%). The isolation rate of

NFGNB was maximum (47%) when the duration of illness exceeded 7 days. Mixed

infections of potential or probable pathogens were observed in 11 patients which

included NFGNB + K. pneumoniae (2); H. influenzae + NFGNB (2); b-  haemolytic

streptococci + H. influenzae (2); b-  haemolytic streptococci + K. pneumoniae

(1) ; S. aureus + K. pneumoniae (1) ; Neisseria sp. + K. pneumoniae (2) and

NFGNB + b-  haemolytic streptococci + H. influenzae (1)

Datta, Manjula

Gopi, P G

Paramasivan, C N

Prabhakar, R

Sivadasan, K

Vallishayee , R S

NIRT Institutional Repository

Indian J. Med. Microbiol., 5, October, 1987 pp. 237-244Bacteriology of Acute Respiratory Infections in ChildrenK. SIVADASAN, C. N. PARAMASIVAN, MANJULA DATTA,R. S. VALLISHAYEE, P. G. GOPI AND R. PRABHAKARTuberculosis Research Centre Indian Council of Medical ResearchMadras-600031, IndiaBacteriological investigations were carried out on 151 children (80 males and71 females) suffering from acute respiratory infections (ARI) to And out bacteriaassociated with ARI.Fifty one children presenting with upper respiratory infec-tions (URI) and 100 with lower respiratory infections (LRI) seen at the outpatientdepartment of the Institute of Child Health and Hospital for Children, Madras,were included in this study.In al l ,  56% of the chi ldren yielded any oneor a mixture of bacteria that could be potential or probable pathogens of ARI.Nonfermenting gram negative bacilli (NFGNB) were the predominant organismsisolated (27%) followed by non-typable ampicillin resistant Haemophilus influenzae(13%) and b. haemolytic streptococci groups C and G (11%). The other bacteriaisolated in this study were Klebsiella pneumoniae (7%), Streptococcus pneumoniae(3%), Neisseria sps. pure (3%) and St phylococcus aureus (1%). The isolation rate ofNFGNB was maximum (47%) when the duration of illness exceeded 7 days. Mixedinfections of potential or probable pathogens were observed in 11 patients whichincluded NFGNB + K. pneumoniae (2); H. influenzae + NFGNB (2); b- haemolyticstreptococci + H. influenzae (2); b- haemolytic streptococci + K. pneumoniae(1) ; S. aureus + K. pneumoniae (1) ; Neisseria sp. + K. pneumoniae (2) andNFGNB + b- haemolytic streptococci + H. influenzae (1).Acute respiratory infections (ARI) in children constitute a major health pro-blem causing considerable mortality in developing countries and morbidity in deve-loped countries. It has been estimated that in most developing countries childrenunder 5 years of age represent about 15% of the total population but over 50% ofall deaths occur in this age group. In these countries ARI along with diarrhoea areidentified as the major killer diseases and the ARI related mortality is accountedto be about 50 times greater than that in developed countries1. In r ral India, themortality rate due to ARI in children under one year was reported to b  2707 per100,0002 as compared to 141 per 100,000 in the United Kingdom3.The aetiology of ARI is very complex since it could be caused by a variety ofagents such as viruses, bacteria, mycoplasmas and chlamydiae. It is difficult to238 K. Sivadasan et alassociate any particular agent as responsible for an episode of ARI since one agentmay predispose the subject to infection with another and different agents may causesimilar clinical symptoms. Diagnosis is further complicated because some potentialpathogens may reside in the respiratory tract of normal healthy individuals.World Health Organization has identified ARI as a priority area for researchand has suggested the following studies : (I) the correlation between clinical synd-romes and aetiological agents, (2) the relative frequency of occurrence of virusesand bacteria as aetiological agents, and (3) the monitoring of the drug sensitivitypattern of the bacterial pathogens isolated.A pilot bacteriological study was conducted in children suffering from ARI tofind out the causative organisms. The results are reported.Materials and MethodsSubjects : From October 1985 to March 1986, 151 children below 6 years ofage presenting with signsa d symptoms of ARI and attending the outpatientdepartment of the Institute of Child Health, Madras, were included in the study.All the children were free from any other acute bacterial illnesses like diarrhoea ormeningitis. Except for 11 children none gave a history of prior treatment.Specimens : Throat swabs,nasal swabs, nasal secretions and laryngeal swabswere collected, coded and transported on wet ice to the laboratory within 3 hoursof collection.Culture and Identification :Isolation and biochemical characterization weredone according to standardmethods4-7. The b. haemolytic streptococci wereserogrouped by the staphylococcal slide coagglutination method8. Serotyping ofHaemophilus influenzae was done by slide agglutination using type specific capsularantisera.Antibiogram : The antibiotic susceptibility testing of the isolates was done onMueller-Hinton agar by the disc-diffusion method9.ResultsOf the children included in the study, there were 80 males and 71 females.59% of the children were below 2 years of age.Of the 151 children studied, 84 (56%) yielded any one or a mixture of bacteriawhich may be considered potential or probable pathogens of ARI, very often alongwith other commensal flora (Table 1). The remaining 67 children (44%) yieldedonly a mixture of normal flora which included Neisseria species (Heavy), dipht-heroids (scanty), and b- haemolytic streptococci with none predominating overthe others.Table 1 : Distribution of children by organisms isolated, clinical diagnosis and duration of illness.No. of organisms isolated aTotal No, in whom Non Fer-    b- haemo- K. pneu- Haemo- Pneumo Staphy- Neisseriano. of organisms menting lytic moniae philus cocci lococcus   sp. (purechil- isolated gm neg  bacilli strepto- influ- aureus growth)dren cocci enzae(a) By clinical diagnosisURI (unspecified) 51 29 15 (29)b 6 (12) 2 (4) 10 (20) 0 1 0LRI (unspecified) 77 42 19 (25) 9 (12) 7 (9) 8 (10) 2 0 4 (5)(5)cLRI (specified)* 23 13 6 (26) 2 1 2 2 0 0(b) By duration (days) of history of illness1 – 3 55 32 13 (24) 9 (16) 2 (4) 7 (13) I 0 2(2)4 – 7 (20)66 34 13 5 (8) 7 (11) 10 (15) 3 (5) 1 2(3)> 7 30 18 14 (47) 3 (IO) 1 3 (10) 0 0 0Total 151 84 40 (26) 17 (11) 10 (7) 20 (13) 4 (3) 1(5)* Asthmatic bronchitis, Bronchopneumonia,Bronchitis, Acute bronchiolitis, Primary complex,PUD and pleural effusion.a Children having more than one type of organisms are added under each type.b Figures in parentheses indicate percentages to the total no. of children.c Figures in parentheses given below the numbers indicate pure growth.4 (3)240 K. Sivadasan et alOf the 96 isolations obtained from the 84 children yielding probable pathogensof ARI, 40 (42%) were non-fermenting gram negative bacilli (NFGNB), 20 (21%)Haemophilus influenzae, 17 (18%) b- haemolytic streptococci, 10 (( 10%) Klebsiellapneumoniae, 4 (4%) Streptococcus pneumoniae, 4 (4%) Neisseria and 1 (1%) coagu-lase positive Staphylococcus aureus.The rates of isolation of NFGNB, the most frequently isolated bacteria in thisstudy, were similar in upper respiratory tract infection (URI) and lower respiratorytract infection (LRI), being 29% and 25% respectively. Five patients yieldedNFGNB in pure culture all of whom had presented with LRI. Like NFGNB, therates of isolation of b- haemolytic streptococci were similar in URIand LRI (12%and 11% respectively). Klebsiella pneumoniae w re more often isolated from LRI(8%) than from URl cases (4%) whereas Ha mophilus influenzae were more oftenisolated from URI (20%) than from LRI cases (10%). However, in both the casesthe difference was not statistically significant. All the 4 isolations of pneumococciand that of Neisseria in pure culture,were from patients who presented with LRI.Mixed growth of potential or probable pathogens of ARI were observed in11 patients. These were NFGNB + K. pneumoniae (2), NFGNB + H. infiuenzae(2), b- haemolytic streptococci + H. influenzae (2), b- haemolytic streptococci +K. pneumoniae (1) and S. aureus + K. pneumoniae (1), Neisseria sp. + K. pneumoniae(2), and NFGNB + b- Haemolytic streptococci + Haemophilus influenzae (1).The isolation of bacteria in relation to the duration of history of illness on theexamination day is also presented in Table 1. it can be seen that the isolation ofNFGNB was maximum when the duration of illness exceeded 7 days as comparedto that when the duration of illness was 1-7 days. The age adjusted rates were 44%and 22% respectively (P=0.03). The isolation rate of b. haemolytic streptcocci washigher when the duration of illness was 1-3 days, the rate being 16% as comparedto 8% when the duration was more than 3 days (Statistically not significant).A study of the isolation of bacteria according to age and sex of the childrenshowed that the NFGNB were more often isolated from children aged 2 years andabove (32%) as compared to those aged below 2 years (22%) and were more predo-minant among males (30%) than among females (23%). However, these differenceswere not statistically significant. The b. haemolytic streptococci were isolated morefrequently from females than from males, the rate being 17% and 6% respectively(statistically not significant).All the NFGNB isolates were completely characterised based on growthcharacters and biochemical reactions and were identified as pseudomonas sps. otherthan Ps. aeruginosa. Majority of the NFGNB isolates (92%) belonged to Pseud -monas pseudoalkaligenes alkaligenes roup. Four strains were identified asPseudomonas pseudomallie group and one strain as Ps. stutzeri. The b- haemolyticBacteriology of ARI in Children 241streptococci belonged to groups C and G. None of the Haemophilus influenzaeisolates were typable with any of the type specific capsular antisera, a, b, c, d,e and f.Antibiogram : The antibiotic susceptibility pattern are shown in Table 2.Almost all the strains of b- haemolytic streptococci were sensitive to most of theTable 2 : Antibiotic susceptibility pattern of the bacteria isolated in the studyDrug Antibioticssensitivity PEN STR ERY CHL TET CEP KAN AMP GEN COL COTstatusSensitive 12Mod. Sensitive 0Resistant 0Sensitive 1Mod. Sensitive13Resistant 4Sensitive 0Mod. Sensitive 1Resistant 6B haemolytic streptococci (n=12)0 4 12 12 10 50 6 0 0 1 612 2 0 0 1 1Haemophilus influenzae (n=18)0 0 18 4 0 03 9 0 13 1 315 9 0 1 17 15Klebsiella pneumoniae(n = 7)1 0 2 2 0 50  0 0 0 0  06 7 5 5 7 211103 8 20 0 1315 10 30 6 61 0 16 1 01002100212001701205NFGNB (n=60)Sensitive 0 0 0 36 36 0 46 2 16 38 54Mod. Sensitive0 4 6 2 6 0 10 2 0 21 0Resistant 60 56 54 22 18 60 4 56 44 1 6a PEN : Penicillin TET : Tetracycline AMP : AmpicillinSTR : Streptomycin C E P  : Cephaloridine  GEN : GentamicinERY : Erythromycin KAN : Kanamycin COL : ColistinCHL : Chloramphenicol  COT : Cotrimaxazole b Some children had NFGNB isolated from more than one specimen collectedat the same time.242 K. Sivadasan et aldrugs tested.In contrast, more than50% of the Haemophilus influenzae weremultidrug resistant and 15 (83%) of the 18 strains were resistant to ampicillin.However, these strains were highly susceptible to chloramphenicol (all the 18) andcotrimoxazole (17 of 18).Majority of the NFGNB and K. pneumoniae isolates were multidrug resistant.Kanamycin, gentamicin and colistin were the most effective drugs for K. pneumoniaeisolates. AS regards NFGNB, cotrimoxazole followed by kanamycin were the mosteffective of the drugs tested.There were 11 patients who gave a history of prior antibiotic treatment.Twoof them yielded NFGNB, and 2, H. influenzae.The remaining 7 had a mixture ofnormal flora.DiscussionThe spectrum of bacteria obtained in our study is quite different from theconventional one where the bacteria most commonly incriminated. in ARI arePneumococcus, H. influenzae typ b, group A b- haemolytic streptococci and Stap-hylococcus aureus 10. The isolation of NFGNB from such a sizable number of ARIpatients has not been documented by anybody so far to our knowledge.The mere isolation of the bacteria,ven of the potential pathogens likeHaemophilus influenzae and Pneumococcus may not always bear any aetiologicalsignificance considering their colonisation at times even in healthy individuals.The invasive nature of these bacteria may probably be demonstrated bythe presenceof their antigen in body fluids like urine and pleural effusion.The antigen of Haemophilus influenzae and pneumococci have already been demon-strated in the urine and pleural fluid of patients presenting with ARI 11,12.The NFGNB in general are commensals of free-living saprophytes.But th irincreasing frequency of isolation from a variety of clinical materials13 in va iousclinical conditions, necessitates a re-evaluation of their role in the human diseaseprocess.The NFGNB have been shown to have the potential to act as secondaryor opportunistic pathogens in man14.The Haemophilus influenzae isolates have failed to react with any of the 6capsular antisera tested and hence were grouped as ‘non-typable’. However, thelack of encapsulation need not necessarily indicate non-pathogenicity. Recently,Wallace et al15 examined a large number of Haemophilus influenzae strains isolatedfrom CSF, blood and genital secretions and found that almost 90% were non-typable but were capable of producing invasive disease process.All the b- haemolytic streptococci isolated were grouped as C and G. This isagain a deviation from the conventional finding in that b- haemolytic streptococciBacteriology of ARI in Children 243of AR1 belong to group A10. Groups C and G are normally seen as commensalsof the respiratory tract of healthy individuals.The pathogenic potential of theseisolates need to be studied further.In general, the exact role of bacteria in the aetiopathogenesis of ARI is farfrom clear. It has been postulated that viruses at times initiate mild respiratoryinfections and predispose the subject to secondary bacterial colonisation and compli-cation. Also endogenous bacterial infection in this situation might acquire potentialto invade tissues deeper and play a role in enhancing the disease process16. Amongthe other possibilities, the viruses may also cause transient immunosuppression17,increased adherence of bacteria to infected cellsl8, or destruction of the integrityof the respiratory epithelial lining19. It is also quite likely that interactionof host factors, environmental conditions, nutritional status, and immunologicalcompetence etc. have a combined role in the complex aetiopathogenesis of ARI.In this study, we have classified the ARI broadly into LRI and URI based onthe signs and symptoms at the time of admission.It is true that URI have a thinbarrier and often appear as associated phenomenon in the same child.It is alsoknown that what starts as an URI is likely to progress to LRI within 48 hours.The highlights of the antibiogram studies were the presence of ampicillinresistant strains of Haemophilus influenzae and multidrug resistant NFGNB andK. pneumoniae. The indiscriminate use of antibiotics in respiratory infections ingeneral might have contributed for this observation. The emergence of suchmultidrug resistant bacteria will have serious consequences if they are capable ofproducing a complicated course of disease process.More reliable procedures like detection of antigens in body fluids, along withisolation and antibiogram studies are essential in the bacteriological surveillance ofARI in children.AcknowledgementThe authors are grateful to the Director, Institute of Child Health and Hospitalfor Children, Egmore, Madras for providing facilities and help for conducting thisstudy. The authors also thank Mr. G. K. Loganathan for technical assistance,Mr. G. Komaleswaran for computational assistance and Mr. B. Doraiswamy forsecretarial help.References1. Leowski, J. : WHO Programme on acute respiratory infections in children; Bull. Int. Un.Tub. 60 (1985), 50.2 . Office of the Registrar General India.Survey on infant and child mortality, 1979. (Ministryof Home Affairs), (1983) p. 54.244 K. Sivadasan et al3.4.5.6.7.8.910.11.12.13.14.15.16.17.18.19.World Health Statistics Annual. 1979 (World Health Organization, Geneva), (1979) p, 403.Collins, C. H. and Lyne, R. M. :Microbiological Methods 5th Edition Butter Worths,(1984).Cruickshank, R., Duguid, J. P., Marmion, B. P.,Swain, R. H. A. : Medical Microbio-logy 12th Edition Vol. II Churchil Livingstone, (1975).Bhujwala, R. A. : Laboratory Manual on non-fermentative gram negative bacilli (Non-fermenters).  A guide to identif ication. New Delhi  :Indian Associat ion of MedicalMicrobiologists, (1982).Pickett, M.J., Pedersen, M.M. : Non-fermenting bacilli associated with man. II. Detectionand identification.Am J. Clin Pathol 54 (1970), 164.Koshi, G., Thangavelu, C. P., Branhmadathan, K. N. :The reliability and rapidity of thecoagglutination technic and its comparison with precipitin technics in the grouping ofstreptococci.Am J. Clin Pathol 71 (1979), 709.Bauer, A. W., Kirby, W. M. M.. Sherris, J. C., Turck. M. : Antibiotic susceptibility testingby a standardised single disc method.Am J  Clin Pathol 45 (1966), 493.Klein, J. O.: Emerging perspectives in management and prevention of infections of therespiratory tract in infants and children.J. Am. Med. Assn. 78 (1985), 38.Lampe, R. M. : Chottipitayasunondh, T., Sunakorn, T. :Detection of bacterial antigen inpleural fluid by counter immunoelectrophoresis J. Pediatr 88 (1976), 557.Turner, R. B., Frederick, G. H., Hendley, J. O. : Counter immunoelectrophoresis of urinefor diagnosis of bacterial pneumonia in pediatric outpatients.Pediatric  71 (1983), 780.Mishra, B., Bhujwala, R.A., Shriniwas : Non-fermenters in human infection – Ind J Med.Res. 83 (1986), 561.Snell, J. J. S. : The distribution and identification of non-fermenting bacteria, PHLSmonograph series No. 4 London HMSO (1973).Wallace, R. J. Jr., Baker, C. J., Quinonone, F. J., Holl is, D. G., Weaver, R. E., Wiss K. :Non-typable Haemophilus influenzae (Biotype 4) as neonatal, maternal and genital pathogens.Rev. Infect. Dis. 5 (1983), 123.Sellers, T. F., Schulman, J., Bouvier, C., Mccune, R., Kilbourne, E. D. : The influence ofinfluenza virus infection on exogenous staphylococcal and endogenous murine bacterialinfection of bronchopulmonary tissues of mice. J. Exp. Med. 114 (1961), 237.Woodruff, J. E., Woodruff. J. J. :Viral Immunology and Immuno-pathology. AcademicPress., London (1975).Sanford, B. A., Skelokov, A., Ramsay, M. A. :Bacterial adherence to virus infected cells ;a cell culture model for bacterial super infections.J. Infect. Dis. 237 (1978), 176.Mims, C. A., White, D. O. :Viral Pathogenesis and Immunology. Blackwell ScientificPublication (1984).Reprint requests : Dr. R. Prabhakar, Tuberculosis Research Centre,Madras-600031 India

Bacteriology of Acute Respiratory Infections in Children

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Bacteriology of Acute Respiratory Infections in Children

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