BACKGROUND
tuberculosis  persists as a major cause of morbidity and mortality, affecting almost a third of the world's population  <cit> .
inadequate detection and cure rates have been identified as reasons for a mounting global tuberculosis burden  <cit> .
human immunodeficiency virus  is by far the major cause of the current increase in tuberculosis infection.
the presence of hiv increases the risk of reactivation of a latent mycobacterium tuberculosis  infection  <cit>  and rapid thus progression of the infection  <cit> ; hiv also increases mtb transmission rates at the community level, therefore threatening the health and survival of hiv- seronegative individuals as well  <cit> .
sub-saharan africa is endemic for both tb and hiv infection  <cit> , and pulmonary tuberculosis  in the hiv-affected countries of eastern and southern africa, such as tanzania, has increased rapidly in the past decades  <cit> .
molecular genotyping is an important tool for the understanding of tb epidemiology.
it can predict transmission rate and identify dominant strains, strains with an enhanced capacity to spread, strains associated with outbreak  <cit> , severe disease  <cit>  and drug resistance.
spacer oligonucleotide typing  is one of the molecular genotyping techniques; it is fast, robust, reliable, easy to perform, and cost-effective  <cit> .
on the basis of the variability of the direct-repeat  locus  <cit> , spoligotyping can detect different m. tuberculosis strains, such as the beijing genotype which is associated with enhanced febrile response in patients during treatment, and multiple drug resistance   <cit> .
for tb control, monitoring the emergence of drug resistant strains is essential.
while detection of drug resistance by phenotype is hindered by the prolonged time to identify resistant strains, genotypic prediction of drug resistance is faster.
data are accumulating on the correlation between gene mutations and phenotypic resistance.
such data however are sparse, particularly from sub-saharan africa where the disease burden is highest.
the primary mechanism for acquiring resistance in m. tuberculosis is the accumulation of point mutations in gene coding for drug targets or drug-converting enzymes  <cit> .
mutations in the catalase peroxidase gene   <cit>  and in a gene encoding the enoyl acyl carrier protein reductase   <cit>  have been found to account for  <dig> to 70% and  <dig> to 15% of inh-resistant mtb isolates, respectively  <cit> .
mutations resulting in an amino acid change within the 81-bp core region of the rna polymerase β-subunit  gene are found in 96% of rifampicin-resistant m. tuberculosis strains  <cit> .
the objectives of this study were to determine the genetic biodiversity of mtb by spoligotyping and to correlate spoligotypes and anti-tuberculous drug susceptibility in hiv-infected and non-hiv patients in northern tanzania, one of the tb and hiv endemic countries of eastern africa.
RESULTS
characteristics of the study population
in total  <dig> positive-culture samples from  <dig> patients were included in the study.
the majority of the patients in this study were from the chagga and masai tribes,  <dig> % and  <dig> %, respectively.
other tribes were represented by less than 5% each.
fifty-four  were peasants,  <dig>  business people,  <dig>  miners and  <dig>  herders, the remaining had other occupations.
the mean age  was  <dig> years .
eighty-three  were male patients.
fourteen patients  had a history of previous treatment for tuberculosis.
forty-seven  patients were hiv seropositive.
mean cd <dig> cell count  for the hiv seropositive patients was  <dig>  cells/ml and for the hiv seronegative group the mean cd <dig> count  was  <dig>  cells/ml.
spoligotypes
a total of  <dig> spoligotypes was identified among the  <dig> m. tuberculosis isolates.
fourteen isolates  had new and unique spoligotypes  while  <dig> isolates  belonged to  <dig> previously known spoligotypes.
a total of  <dig> isolates  from nine different phylogenetic clusters formed the major isolates .
these were cas1-kili with  <dig>  isolates , lam11- zwe  <dig>  , nd  <dig> , eai  <dig> , beijing  <dig>  and t-undefined  <dig>  as well as cas1-delhi , t <dig>  and lam <dig>  with  <dig> isolates  each .
three new shared spoligotypes  were established from our findings by comparing them with the spoligotypes which were available in the spoldb4: one eai  with that found in zambia, one t-undefined  with that found in the usa and one cas <dig> variant – undefined  with that found in sweden.
drug susceptibility testing
out of  <dig> tb isolates which were subjected to dst,  <dig>  were resistant to at least one anti-tb drug.
eight of the  <dig>  were monoresistant strains:  <dig> resistant to inh and one to streptomycin.
four strains  were resistant to multiple drugs: one  was resistant to inh and streptomycin and the other three  strains were mdr strains: two  strains were resistant to all four anti-tb drugs and one  strain was resistant to inh, rifampicin and ethambutol resistance of the  <dig> isolates for each drug was as follows: inh  <dig> strains , streptomycin  <dig> , rifampicin  <dig> , and ethambutol  <dig> .
four of the  <dig> mtb isolates  were found to have a mutation in a katg gene codon  <dig>  four of the  <dig> tested isolates were found to have a mutation in the hotspot region of the rpob gene.
of the  <dig> strains phenotypically resistant to inh, four strains were also genotypically resistant to inh.
the sensitivity of the mutant katg gene to predict phenotypical resistance to inh was  <dig> % and the specificity was 100%.
all three strains phenotypically resistant to rifampicin were also genotypically resistant to rifampicin.
both sensitivity and specificity of a mutation in the rpob gene to predict phenotypical resistance to rifampicin was 100%.
as shown in table  <dig>  two of the  <dig> isolates  belonging to four variants of the cas <dig> family  showed resistance to at least one drug and four could not be tested.
six of the  <dig> isolates  of the lam family  showed resistance to one or more anti-tb drugs.
three of the  <dig> isolates  of the t family  showed resistance.
one of the  <dig> isolates  of the eai family , one of the  <dig> isolates  of the nd family, and one of the three isolates  from the manu family  showed resistance to at least one anti-tb drug.
none of the seven m. tuberculosis beijing isolates was resistant to anti-tb drugs.
* cas: cas1-kili; cas1-delhi; cas1-undefined;cas2
** lam: lam11-zwe; lam9; lam <dig> or s; lam-undefined
*** t: t-undefined; t1; t3-uga; t3
# eai: eai; eai-variant; eai-undefined
## manu: manu1; manu <dig>
out of the  <dig> resistant isolates two  were new and unique isolates : the three mdr isolates were cas1- kili , eai  and lam  <dig> – zwe
previous tb treatment, hiv status and drug resistance
out of  <dig> patients who had a history of previous treatment for ptb, one  had a mdr-mtb strain and the other  <dig>  had strains sensitive to all four first line anti-tb drugs.
five of the  <dig> hiv-infected individuals  showed resistance to at least one drug.
three of the  <dig> hiv – infected individuals  had a history of previous treatment for tb and none of them had strain resistant to anti-tb drug.
discussion
there was a wide diversity of spoligotypes in this study group; the  <dig> mtb isolates produced  <dig> different spoligotypes.
the clades observed in this study were more than three-quarters of the total of  <dig> clades/lineages currently documented in the fourth international spoligotyping database, spoldb <dig>  <cit> .
this diversity may be attributed to increased human movement in this area due tourism, mining, asylum seeking  and transborder/international business.
historically, many people from europe and asia also lived here during pre- and post-independence times.
the structure of the tb population is determined by geography, demography, and human migration.
studies have shown that the host's geographical origin is predictive of the clinical m. tuberculosis isolates and there is an apparent stable association of tb bacilli populations with their human hosts in various environments  <cit> .
new types  accounted for one-tenth of all spoligotypes in this study.
the low percentage of new types may also be a result of increased human movements.
countries with a history of isolation have been shown to have a large number of new spoligotypes  <cit> .
in this study two of the three new shared spoligotypes were formed between two geographically widely separated isolates .
this again is more likely to be due to the increased human movement than homoplasy .
if it is assumed that tuberculosis may have affected the early hominids in east africa, evolved clonally and then spread to the rest of the world coincidentally with human migration out of africa  <cit> , then it is interesting to find that almost all strains go back to the origin of homo sapiens sapiens.
the site of this study is within the area of olduvai gorge in northern tanzania, which is regarded as the "cradle of mankind".
in this context, strains no.
116– <dig> with manu-derived spoligotypes are of particular interest .
among the different phylogenetic clusters found in this study, there were only nine major clusters with five or more isolates, but they comprised  <dig> % of all isolates.
this indicates the high transmission rate within the population.
this high transmission rate may also be influenced by the marked prevalence of hiv infection which increases the risk of tuberculosis for all people in a community, both those with hiv infection and the hiv seronegative community members  <cit> .
two clusters were by far the most prevalent: cas1-kili and lam11-zwe family, with a prevalence exceeding ten percent.
the predominance of these two families by more than ten percent has been demonstrated by another study based on is 6110-restriction fragment length polymorphism .
the study showed that the kilimanjaro and meru families were the most prevalent in this area  <cit> , the names of the families being derived from the two adjacent mountains found in this area.
while the kilimanjaro family refers to cas1-kili, the meru family is identical to lam11-zwe  <cit> .
another recent study, performed in dar-es-salaam, suggested the existence of new cas1-kili genotype variants   <cit> .
however, the absence of spacer  <dig> and  <dig> in the spoligotype-signatures reported by these authors was not found, even once, in our study.
a single clinical isolate, strain  <dig>  looks similar to the cas-dar variants.
this may be explained either by a specific loss of spacers  <dig> and  <dig> in the cas1-dar variants or by false negative hybridization spots.
spacer  <dig> and  <dig> may indeed sometimes provide barely interpretable results.
if confirmed, the absence of spacers  <dig> and  <dig> may provide interesting clues about the microevolution of cas1-kili in tanzania.
more than 5% of cases were beijing isolates which were the fifth most frequent spoligotype.
the presence of seven beijing isolates had already been reported in dar-es-salaam  <cit> .
the mean age of the patients with the beijing family was the lowest compared to those with other isolates .
it has already been reported that beijing is associated with young age  <cit>  which implies recent and ongoing transmission.
a striking finding was that not one single case of m. bovis or m. africanum was found in this study.
this study cohort consisted mainly of peasants and herders, including the masai people who are essentially semi-nomads or herders and their staple food includes milk and meat.
in uganda which is a neighbouring country, other genotypes of the m. tuberculosis complex, previously designated as "m. africanum 2" are the major cause of human tuberculosis  <cit> .
this finding may be a result of improved livestock and animal husbandry in tanzania or due to anthropologically rooted differences between uganda and tanzania.
all resistant isolates except one were resistant to inh, either alone or in combination with other drugs.
the level of inh resistance was high; a similar trend has been observed in many african countries; in some countries up to one-third of the isolates is resistant to inh  <cit> .
this rate is alarming, especially since inh is the first-line drug which is used throughout the course of tb treatment.
this also means a high probability of the development of mdr in the future, since it has been observed that mdr often develops from initial inh-monoresistant strains  <cit> .
several reports show a low prevalence of mdr-mtb in africa compared to asia and eastern europe  <cit> .
but the trend seems to be steadily increasing since previous reports from tanzania showed that inh monoresistance was about 5% and mdr was about 1%  <cit>  while our study reveals a more than two-fold increase in both inh resistance and mdr.
the upward trend in resistance has also been noted in neighboring countries  <cit> .
despite its high prevalence, the cas  <dig> family showed the least association with anti-tb drug resistance ; family lam and t were more frequently associated with anti-tb drug resistance.
another interesting aspect was the fact that all mtb beijing isolates in this study were susceptible to all anti-tb drugs unlike reports from other studies  <cit> .
a previous study in indonesia also showed no significant association between beijing strains and drug resistance  <cit> .
one-third of the study population was infected by both hiv and tb; this is the common trend in sub saharan africa  <cit> .
the association of hiv infection, however, with previous treatment for tb was not statistically significant and that with anti-tb drug resistance was absent in this study.
the smaller number of hiv- infected patients with a history of previous treatment for tb may be attributed to high mortality associated with the first mtb infection in tb/hiv co-infected patients  <cit> .
there was no association between hiv status and spoligopatterns except for beijing whereby only one person was hiv seropositive.
the mean cd <dig> count for patients with beijing was the lowest, although all patients except one were hiv seronegative.
this low cd <dig> count despite being hiv seronegative may be due to the pronounced virulence of the beijing strain.
it has been demonstrated that the beijing family is more virulent than other m. tuberculosis strains.
the virulence is attributed to the ability of the strain to produce phenolic glycolipid which is able to interfere with host immunity  <cit> .
CONCLUSIONS
in this study we found a wide diversity of spoligotypes with predominance of two genotype families.
the beijing family was also among the prevalent phylogenetic cluster.
the most prevalent cluster cas1-kili and the most virulent beijing were not or barely associated with anti-tb drug resistance.
a substantial proportion of resistant isolates was found, inh monoresistance being the highest and thus signaling the danger of increasing mdr in the future.
mdr was higher than that described in previous reports from tanzania.

 tuberculosis persists as a major cause of morbidity and mortality, affecting almost a third of the world's population. inadequate detection and cure rates have been identified as reasons for a mounting global tuberculosis burden. human immunodeficiency virus is by far the major cause of the current increase in tuberculosis infection. the presence of hiv increases the risk of reactivation of a latent mycobacterium tuberculosis infection and rapid thus progression of the infection; hiv also increases mtb transmission rates at the community level, therefore threatening the health and survival of hiv- seronegative individuals as well. sub-saharan africa is endemic for both tb and hiv infection, and pulmonary tuberculosis in the hiv-affected countries of eastern and southern africa, such as tanzania, has increased rapidly in the past decades. molecular genotyping is an important tool for the understanding of tb epidemiology. it can predict transmission rate and identify dominant strains, strains with an enhanced capacity to spread, strains associated with outbreak, severe disease and drug resistance. spacer oligonucleotide typing is one of the molecular genotyping techniques; it is fast, robust, reliable, easy to perform, and cost-effective. on the basis of the variability of the direct-repeat locus, spoligotyping can detect different m. tuberculosis strains, such as the beijing genotype which is associated with enhanced febrile response in patients during treatment, and multiple drug resistance. for tb control, monitoring the emergence of drug resistant strains is essential. while detection of drug resistance by phenotype is hindered by the prolonged time to identify resistant strains, genotypic prediction of drug resistance is faster. data are accumulating on the correlation between gene mutations and phenotypic resistance. such data however are sparse, particularly from sub-saharan africa where the disease burden is highest. the primary mechanism for acquiring resistance in m. tuberculosis is the accumulation of point mutations in gene coding for drug targets or drug-converting enzymes. mutations in the catalase peroxidase gene and in a gene encoding the enoyl acyl carrier protein reductase have been found to account for to 70% and to 15% of inh-resistant mtb isolates, respectively. mutations resulting in an amino acid change within the 81-bp core region of the rna polymerase β-subunit gene are found in 96% of rifampicin-resistant m. tuberculosis strains. the objectives of this study were to determine the genetic biodiversity of mtb by spoligotyping and to correlate spoligotypes and anti-tuberculous drug susceptibility in hiv-infected and non-hiv patients in northern tanzania, one of the tb and hiv endemic countries of eastern africa.  characteristics of the study population in total positive-culture samples from patients were included in the study. the majority of the patients in this study were from the chagga and masai tribes, % and %, respectively. other tribes were represented by less than 5% each. fifty-four were peasants, business people, miners and herders, the remaining had other occupations. the mean age was years. eighty-three were male patients. fourteen patients had a history of previous treatment for tuberculosis. forty-seven patients were hiv seropositive. mean cd cell count for the hiv seropositive patients was cells/ml and for the hiv seronegative group the mean cd count was cells/ml. spoligotypes a total of spoligotypes was identified among the m. tuberculosis isolates. fourteen isolates had new and unique spoligotypes while isolates belonged to previously known spoligotypes. a total of isolates from nine different phylogenetic clusters formed the major isolates. these were cas1-kili with isolates, lam11- zwe, nd, eai, beijing and t-undefined as well as cas1-delhi, t and lam with isolates each. three new shared spoligotypes were established from our findings by comparing them with the spoligotypes which were available in the spoldb4: one eai with that found in zambia, one t-undefined with that found in the usa and one cas variant – undefined with that found in sweden. drug susceptibility testing out of tb isolates which were subjected to dst, were resistant to at least one anti-tb drug. eight of the were monoresistant strains: resistant to inh and one to streptomycin. four strains were resistant to multiple drugs: one was resistant to inh and streptomycin and the other three strains were mdr strains: two strains were resistant to all four anti-tb drugs and one strain was resistant to inh, rifampicin and ethambutol resistance of the isolates for each drug was as follows: inh strains, streptomycin, rifampicin, and ethambutol. four of the mtb isolates were found to have a mutation in a katg gene codon four of the tested isolates were found to have a mutation in the hotspot region of the rpob gene. of the strains phenotypically resistant to inh, four strains were also genotypically resistant to inh. the sensitivity of the mutant katg gene to predict phenotypical resistance to inh was % and the specificity was 100%. all three strains phenotypically resistant to rifampicin were also genotypically resistant to rifampicin. both sensitivity and specificity of a mutation in the rpob gene to predict phenotypical resistance to rifampicin was 100%. as shown in table two of the isolates belonging to four variants of the cas family showed resistance to at least one drug and four could not be tested. six of the isolates of the lam family showed resistance to one or more anti-tb drugs. three of the isolates of the t family showed resistance. one of the isolates of the eai family, one of the isolates of the nd family, and one of the three isolates from the manu family showed resistance to at least one anti-tb drug. none of the seven m. tuberculosis beijing isolates was resistant to anti-tb drugs. * cas: cas1-kili; cas1-delhi; cas1-undefined;cas2 ** lam: lam11-zwe; lam9; lam or s; lam-undefined *** t: t-undefined; t1; t3-uga; t3 # eai: eai; eai-variant; eai-undefined ## manu: manu1; manu out of the resistant isolates two were new and unique isolates: the three mdr isolates were cas1- kili, eai and lam – zwe previous tb treatment, hiv status and drug resistance out of patients who had a history of previous treatment for ptb, one had a mdr-mtb strain and the other had strains sensitive to all four first line anti-tb drugs. five of the hiv-infected individuals showed resistance to at least one drug. three of the hiv – infected individuals had a history of previous treatment for tb and none of them had strain resistant to anti-tb drug. discussion there was a wide diversity of spoligotypes in this study group; the mtb isolates produced different spoligotypes. the clades observed in this study were more than three-quarters of the total of clades/lineages currently documented in the fourth international spoligotyping database, spoldb. this diversity may be attributed to increased human movement in this area due tourism, mining, asylum seeking and transborder/international business. historically, many people from europe and asia also lived here during pre- and post-independence times. the structure of the tb population is determined by geography, demography, and human migration. studies have shown that the host's geographical origin is predictive of the clinical m. tuberculosis isolates and there is an apparent stable association of tb bacilli populations with their human hosts in various environments. new types accounted for one-tenth of all spoligotypes in this study. the low percentage of new types may also be a result of increased human movements. countries with a history of isolation have been shown to have a large number of new spoligotypes. in this study two of the three new shared spoligotypes were formed between two geographically widely separated isolates. this again is more likely to be due to the increased human movement than homoplasy. if it is assumed that tuberculosis may have affected the early hominids in east africa, evolved clonally and then spread to the rest of the world coincidentally with human migration out of africa, then it is interesting to find that almost all strains go back to the origin of homo sapiens sapiens. the site of this study is within the area of olduvai gorge in northern tanzania, which is regarded as the "cradle of mankind". in this context, strains no. 116– with manu-derived spoligotypes are of particular interest. among the different phylogenetic clusters found in this study, there were only nine major clusters with five or more isolates, but they comprised % of all isolates. this indicates the high transmission rate within the population. this high transmission rate may also be influenced by the marked prevalence of hiv infection which increases the risk of tuberculosis for all people in a community, both those with hiv infection and the hiv seronegative community members. two clusters were by far the most prevalent: cas1-kili and lam11-zwe family, with a prevalence exceeding ten percent. the predominance of these two families by more than ten percent has been demonstrated by another study based on is 6110-restriction fragment length polymorphism. the study showed that the kilimanjaro and meru families were the most prevalent in this area, the names of the families being derived from the two adjacent mountains found in this area. while the kilimanjaro family refers to cas1-kili, the meru family is identical to lam11-zwe. another recent study, performed in dar-es-salaam, suggested the existence of new cas1-kili genotype variants. however, the absence of spacer and in the spoligotype-signatures reported by these authors was not found, even once, in our study. a single clinical isolate, strain looks similar to the cas-dar variants. this may be explained either by a specific loss of spacers and in the cas1-dar variants or by false negative hybridization spots. spacer and may indeed sometimes provide barely interpretable results. if confirmed, the absence of spacers and may provide interesting clues about the microevolution of cas1-kili in tanzania. more than 5% of cases were beijing isolates which were the fifth most frequent spoligotype. the presence of seven beijing isolates had already been reported in dar-es-salaam. the mean age of the patients with the beijing family was the lowest compared to those with other isolates. it has already been reported that beijing is associated with young age which implies recent and ongoing transmission. a striking finding was that not one single case of m. bovis or m. africanum was found in this study. this study cohort consisted mainly of peasants and herders, including the masai people who are essentially semi-nomads or herders and their staple food includes milk and meat. in uganda which is a neighbouring country, other genotypes of the m. tuberculosis complex, previously designated as "m. africanum 2" are the major cause of human tuberculosis. this finding may be a result of improved livestock and animal husbandry in tanzania or due to anthropologically rooted differences between uganda and tanzania. all resistant isolates except one were resistant to inh, either alone or in combination with other drugs. the level of inh resistance was high; a similar trend has been observed in many african countries; in some countries up to one-third of the isolates is resistant to inh. this rate is alarming, especially since inh is the first-line drug which is used throughout the course of tb treatment. this also means a high probability of the development of mdr in the future, since it has been observed that mdr often develops from initial inh-monoresistant strains. several reports show a low prevalence of mdr-mtb in africa compared to asia and eastern europe. but the trend seems to be steadily increasing since previous reports from tanzania showed that inh monoresistance was about 5% and mdr was about 1% while our study reveals a more than two-fold increase in both inh resistance and mdr. the upward trend in resistance has also been noted in neighboring countries. despite its high prevalence, the cas family showed the least association with anti-tb drug resistance; family lam and t were more frequently associated with anti-tb drug resistance. another interesting aspect was the fact that all mtb beijing isolates in this study were susceptible to all anti-tb drugs unlike reports from other studies. a previous study in indonesia also showed no significant association between beijing strains and drug resistance. one-third of the study population was infected by both hiv and tb; this is the common trend in sub saharan africa. the association of hiv infection, however, with previous treatment for tb was not statistically significant and that with anti-tb drug resistance was absent in this study. the smaller number of hiv- infected patients with a history of previous treatment for tb may be attributed to high mortality associated with the first mtb infection in tb/hiv co-infected patients. there was no association between hiv status and spoligopatterns except for beijing whereby only one person was hiv seropositive. the mean cd count for patients with beijing was the lowest, although all patients except one were hiv seronegative. this low cd count despite being hiv seronegative may be due to the pronounced virulence of the beijing strain. it has been demonstrated that the beijing family is more virulent than other m. tuberculosis strains. the virulence is attributed to the ability of the strain to produce phenolic glycolipid which is able to interfere with host immunity.  in this study we found a wide diversity of spoligotypes with predominance of two genotype families. the beijing family was also among the prevalent phylogenetic cluster. the most prevalent cluster cas1-kili and the most virulent beijing were not or barely associated with anti-tb drug resistance. a substantial proportion of resistant isolates was found, inh monoresistance being the highest and thus signaling the danger of increasing mdr in the future. mdr was higher than that described in previous reports from tanzania. 
hiv status was not associated with spoligotypes, resistance or previous tb treatment. sub-saharan africa is endemic for both tb and hiv infection. four strains were resistant to multiple drugs: one was resistant to inh and streptomycin and the other three were mdr strains: one was resistant to inh, rifampicin and ethambutol and two were resistant to all four anti-tb drugs. the spoligotypes were correlated with anti-tuberculous drug susceptibility in hiv-infected and non-hiv patients from tanzania. twelve of the phenotypically tested strains were resistant to anti-tb drugs. determination of the prevalence of m. tuberculosis strains and their drug susceptibility is important for tb control. eight were monoresistant strains: to isoniazid and one to streptomycin. fourteen isolates had new and unique spoligotypes while isolates belonged to known spoligotypes.
 tuberculosis is a major health problem and hiv is the major cause of the increase in tb. sub-saharan africa is endemic for both tb and hiv infection. determination of the prevalence of m. tuberculosis strains and their drug susceptibility is important for tb control. tb positive culture, bal fluid or sputum samples from patients were collected and genotyped. the spoligotypes were correlated with anti-tuberculous drug susceptibility in hiv-infected and non-hiv patients from tanzania.  one-third of patients were tb/hiv co-infected. forty-seven spoligotypes were identified. fourteen isolates had new and unique spoligotypes while isolates belonged to known spoligotypes. the major spoligotypes contained nine clusters: cas1-kili %, lam11- zwe %, nd %, eai %, beijing %, t-undefined %, cas1-delhi %, t % and lam %. twelve of the phenotypically tested strains were resistant to anti-tb drugs. eight were monoresistant strains: to isoniazid and one to streptomycin. four strains were resistant to multiple drugs: one was resistant to inh and streptomycin and the other three were mdr strains: one was resistant to inh, rifampicin and ethambutol and two were resistant to all four anti-tb drugs. mutation in the katg gene codon and the rpob hotspot region showed a low and high sensitivity, respectively, as predictor of phenotypic drug resistance.  cas1-kili and lam11-zwe were the most common families. strains of the beijing family and cas1-kili were not or least often associated with resistance, respectively. hiv status was not associated with spoligotypes, resistance or previous tb treatment. 